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HomeMy WebLinkAboutCity_of_Oshkosh_Campbell_Creek_SWMP_Final_May_2006 Report North Branch Campbell Creek Stormwater Management Plan City of Oshkosh, WI May 2006 Report for City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Prepared by: STRAND ASSOCIATES, INC.® 910 West Wingra Drive Madison, WI 53715 www.strand.com May 2006 TABLE OF CONTENTS Page No. or Following EXECUTIVE SUMMARY SECTION 1–INTRODUCTION 1.01 Introduction................................................................................................ 1- 1 1.02 Scope of Study........................................................................................... 1- 1 1.03 Location of Study Area............................................................................... 1- 3 1.04 Other Similar Studies................................................................................. 1- 3 1.05 Applicable Standards and Design Criteria................................................. 1- 4 1.06 Phase II Stormwater Permit....................................................................... 1- 6 1.07 Definitions and Abbreviations.................................................................... 1- 6 SECTION 2–CONTRIBUTING WATERSHED CHARACTERISTICS 2.01 Basin Characteristics Affecting Stormwater Runoff................................... 2- 1 2.02 Expected Precipitation and Depths............................................................ 2- 4 2.03 Fox River and Lake Winnebago Regulatory Levels................................... 2- 5 2.04 Gauging Station on Fox River and Lake Winnebago................................. 2- 5 2.05 Lake Winnebago 2004-2005 Regulation Strategy..................................... 2- 6 2.06 Rainfall Gauges in Oshkosh...................................................................... 2- 6 2.07 Locations of Existing Flooding Problems................................................... 2- 7 SECTION 3–ENGINEERING ANALYSIS 3.01 Hydrologic Analysis.................................................................................... 3- 1 3.02 Hydraulic Analysis...................................................................................... 3- 2 SECTION 4–ALTERNATIVE ANALYSIS 4.01 General...................................................................................................... 4- 1 4.02 Alternative 1–Detention at Four Locations................................................. 4- 5 4.03 Alternative 2–Increase Conveyance Capacity in North Branch System.... 4- 9 4.04 Alternative 3–Flow Diversion Modification................................................. 4- 12 4.05 Alternative 4–Stormwater Pump Station at Downstream End of Campbell Creek......................................................................................... 4-16 4.06 Alternative 5–Single Mix of Project Components....................................... 4-18 4.07 Alternative 6............................................................................................... 4-20 4.08 Alternative 7............................................................................................... 4-21 4.09 Alternative 8............................................................................................... 4-24 4.10 Alternative 9............................................................................................... 4-26 4.11 Alternative 10............................................................................................. 4-28 4.12 Alternative 11............................................................................................. 4-30 4.13 Summary of Alternatives and Alternatives Analysis................................... 4-31 4.14 Storm Sewer Capacity Analysis Under Future Land Use Conditions for Modeled Storm Sewers with Alternative 7 in Place............ 4-33 4-15 Storm Sewer Sizing for Main Branch to Convey 10-Year Flow with Recommended Alternative in Place........................................... 4-33 TABLE OF CONTENTS Continued Page No. or following 4.16 Changes in Diversion at Diversion Points 1, 2, and 3 with Alternative 7 in Place................................................................................. 4-33 4.17 Off-line Stormwater Ponds (NR 116)......................................................... 4-33 SECTION 5–CONCLUSIONS AND RECOMMENDATIONS 5.01 General...................................................................................................... 5- 1 5.02 Recommendations for Achieving Stormwater Management Goals........... 5- 1 5.03 Implementation Plan.................................................................................. 5- 2 5.04 Funding Opportunities................................................................................ 5- 3 5.05 Policies and Practices................................................................................ 5- 3 5.06 Conclusion................................................................................................. 5- 5 APPENDICES APPENDIX A–FLOODING PHOTOGRAPHS APPENDIX B–DRAINAGE EVALUATION FORM APPENDIX C–STORMWATER FUNDING BROCHURE TABLES ES.04-1 Summary of Alternatives............................................................................ ES-4 ES.05-1 Stormwater Plan Components and Implementation Plan.......................... ES-5 2.01-1 Hydrologic Soils Groups (HSG)................................................................. 2- 2 2.01-2 Campbell Creek Watershed Soils.............................................................. 2- 3 2.01-3 Existing Conditions Hydrologic Parameter................................................. 2- 4 2.01-4 Future Conditions Hydrologic Parameter................................................... 2- 4 2.02-1 Design Storm Rainfall Depths, Bulletin 71................................................. 2- 4 2.03-1 Regulatory Levels–Lake Winnebago (National Geodetic Vertical Datum of 1929–NGVD 1929)......................... 2- 5 2.03-2 Regulatory Levels–Confluence with Campbell Creek (NGVD 1929)......... 2- 5 2.05-1 Lake Winnebago 2004-2006 Regulation Strategy..................................... 2- 6 2.07-1 Locations of Existing Flooding................................................................... 2- 9 3.01-1 Peak Discharge Rates by Subasin–Existing Conditions............................ 3- 2 3.01-2 Peak Discharge Rates by Subbasin–Future Conditions............................ 3- 2 3.02-1 Boundary Conditions at Sawyer Creek/Westfield Outfall (NGVD 1929).... 3- 3 3.02-2 Boundary Conditions at Sawyer Creek/Washburn Street Outfall (NGVD 1929)............................................................................................. 3- 3 3.02-3 Storm System Characteristics.................................................................... 3- 5 3.02-4 Existing Peak Charges–Elevations Summary............................................ 3- 5 4.01-1 Existing Available Detention...................................................................... 4- 1 4.01-2 Proposed Alternatives Detention Availability–Future Conditions............... 4- 1 4.01-3 Alternative Components............................................................................. 4- 3 4.02-1 Vacant Parcel Information–Component 1c................................................ 4- 6 4.02-2 Alternative 1–Opinion of Probable Cost–Detention at Four Locations....... 4- 8 4.02-3 Detention at Four Locations Effects at Landmark Plaza–Future Conditions–Alternative 1............................................................................ 4- 9 TABLE OF CONTENTS Continued Page No. or following TABLES (Continued) 4.03-1 Alternative 2–Opinion of Probable Cost–Increase Conveyance Capacity in North Branch System.............................................................. 4-11 4.03-2 Increased Conveyance Capacity Effects at Landmark Plaza–Future Conditions–Alternative 2............................................................................ 4-12 4.04-1 Alternative 3–Opinion of Probable Cost–Diversion Modification................ 4-15 4.04-2 Diversion Modification Effects–Future Conditions–Alternative 3............... 4-16 4.05-1 Opinion of Probable Cost–Stormwater Pump Station–Alternative 4.......... 4-17 4.05-2 Pump Effects at Landmark Plaza–Future Conditions with Pump Station at Campbell Creek Discharge–Alternative 4.................................. 4-18 4.06-1 Alternative 5–Opinion of Probable Costs–Select Detention....................... 4-18 4.06-2 Future Conditions Effects–Alternative 5..................................................... 4-19 4.07-1 Alternative 6–Opinion of Probable Cost..................................................... 4-20 4.07-2 Future Conditions Effects–Alternative 6..................................................... 4-21 4.08-1 Alternative 7–Opinion of Probable Cost..................................................... 4-23 4.08-2 Future Conditions Effects–Alternative 7..................................................... 4-24 4.09-1 Alternative 8–Opinion of Probable Cost..................................................... 4-25 4.09-2 Future Conditions Effects–Alternatives 8................................................... 4-26 4.10-1 Alternative 9–Opinion of Probable Cost..................................................... 4-27 4.10-2 Future Conditions Effects–Alternative 9..................................................... 4-27 4.11-1 Alternative 10–Opinion of Probable Cost................................................... 4-29 4.11-2 Future Conditions Effects–Alternative 10................................................... 4-29 4.12-1 Alternative 11–Opinion of Probable Cost................................................... 4-30 4.12-2 Future Conditions Effects–Alternative11.................................................... 4-31 4.13-1 Summary of Alternatives............................................................................ 4-31 4.13-2 Summary of Effects–Ranking Data............................................................ 4-31 4-13-3 Summary of Effects–Rankings................................................................... 4-31 4.13-4 Least Amount of Increase in 100-Year, 2-Hour Duration Flow Rates at Sawyer Creek/USH 41 Outfall Ranking....................................... 4-32 4.13-5 Maximizes Use of Storage in Watershed................................................... 4-32 5.03-1 Stormwater Plan Components and Implementation Plan (Cost Includes 25 Percent Engineering and Contingencies)..................... 5- 2 TABLE OF CONTENTS Continued Page No. or following FIGURES 1.03-1 Study Area Location Relative to DNR Watersheds.................................... 1- 3 2.01-1 Drainage Area Map..........................................................................Pocket Folder 2.01-2 Soils Map................................................................................................... 2- 2 2.01-3 Existing Land Use–Impervious Area Map.................................................. 2- 4 2.01-4 Future Land Use–Impervious Area Map.................................................... 2- 4 2.01-5 Existing Land Use–Smart Growth Plan...................................................... 2- 4 2.01-6 20-Year Land Use Plan–Smart Growth Plan ............................................ 2- 4 2.01-7 Zoning Map–Smart Growth Plan................................................................ 2- 4 2.03-1 Fox River Flood Profile.............................................................................. 2- 5 2.03-2 Sawyer Creek Flood Profiles..................................................................... 2- 5 2.06-1 June 10 and 11, 2004 Storm Event–USACE Gauge in Oshkosh, Wisconsin................................................................................................... 2- 7 2.07-1 Problem Areas........................................................................................... 2- 8 3.02-1 Existing Conditions Pipe Capacity...................................................Pocket Folder 3.02-2 Existing Survey Data at Landmark Plaza and Tippler................................ 3- 4 3.02-3 Existing Conditions Diversion Analysis...................................................... 3- 6 4.02-1a Alternative 1–Component 1A–Detention at Vacant Lot South of Landmark Plaza......................................................................................... 4- 5 4.02-1b Alternative 1–Component 1B–Detention at Golf Course........................... 4- 5 4.02-1c Alternative 1–Component 1C– Detention at Vacant Lot Southeast of 9th/Washburn Street Intersection... 4- 6 4.02-1d Alternative 1–Component 1D– 100-Year Overflow to and Detention at Tippler Junior High...................... 4- 6 4.02-1e Alternative 1–Component 1E..................................................................... 4- 6 4.03-1 Alternative 2–Component 2C– Downstream Pipe Upsizing to Convey the 100-Year Flow........................ 4- 9 4.03-2a Alternative 2–Component 2A– Additional Internal Capacity at Landmark Plaza........................................ 4- 9 4.04-1 100-Year Storm Sewer in DOT ROW........................................................ 4-12 4.04-2 Alternative Expanded Tippler Detention.................................................... 4-12 4.04-3 Alternative Expanded Golf Course............................................................. 4-12 4.05-1 Alternative 4 – Stormwater Pump Station at Downstream End of Campbell Creek........... 4-16 4.08-1 Alternative 7–Components......................................................................... 4-21 4.14-1 Pipe Capacity Analysis with Alternative 7 in Place..........................Pocket Folder 4.15-1 Downstream Pipe Upsizing to Convey the 10-Year Flow with Alternative 7 in Place................................................................. 4-33 4.16-1 Diversion Analysis–With Alternative 7 in Place.......................................... 4-33 EXECUTIVE SUMMARY City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Executive Summary Prepared by Strand Associates, Inc.® ES-1 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\ES.doc\052506 ES.01 INTRODUCTION This report summarizes the methodology and results of a study done by Strand Associates, Inc. to develop a stormwater management plan for the North Branch of Campbell Creek Watershed in the City of Oshkosh. The North Branch Campbell Creek Watershed is predominantly a fully developed urban watershed that comes together at W. 4th Avenue and Sawyer Street with the South Branch of Campbell Creek. The North Branch of Campbell Creek and specifically the Landmark Plaza have experienced recent flooding. A sampling of photographs taken by City staff on June 11, 2004, documenting the flooding that occurred as a result of a June 10/11, 2004, storm event is included in Appendix A. Much of the development in this watershed occurred prior to the advent and implementation of strong guidelines on stormwater management, resulting in several areas with stormwater system capacity issues. This stormwater management plan, in conjunction with previous stormwater studies, will address ways to mitigate the existing stormwater flooding problems in the North Branch of Campbell Creek watershed and suggest ways to decrease the impacts of future development. ES.02 CONTRIBUTING WATERSHED CHARACTERISTICS The Campbell Creek watershed is a highly developed watershed with large amounts of impervious surfaces such as streets, parking lots, and rooftops. The high level of impervious surface results in high peak discharge rates and runoff volumes during storm events. The soils in the Campbell Creek watershed are predominantly Type C soils (Kewaunee Silt Loam underlain by clay subsoil). Thus, there is little infiltration potential in the underlying soils. Seven flooding locations in the Campbell Creek watershed were identified. Apparent causes of the flooding and type of damage incurred are listed in Table 2.07-1. The June 10 and 11, 2004, storm event that prompted this study compares to a 20-year, 12-hour storm event (cumulative 3.63 inches of rainfall). The lower reaches of the Campbell Creek storm sewer system (and adjacent linked Sawyer Creek storm sewer system) are affected by the Lake Winnebago pool elevation. When lake levels are high, the storm sewer capacity is reduced because the pipe is partially full of water at the start of a storm event. ES.03 HYDROLOGIC ANALYSIS Hydrologic models were developed for the Campbell Creek drainage area using the RUNOFF module of the computer model XP-SWMMTM. XP-SWMMTM estimates peak stormwater discharges and volumes based on mathematical input parameters representing precipitation depth and time distribution, drainage area, land use, and time of concentration for each subbasin. This model was used to determine drainage system capacities and analyze performance of the proposed alternatives. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Executive Summary Prepared by Strand Associates, Inc.® ES-2 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\ES.doc\052506 Computer modeling results appear to closely match observed locations, depths, and durations of flooding in the Campbell Creek watershed. However, modeling also indicates that severity of flooding in the lower reaches of the Campbell Creek watershed is strongly tied to the water surface elevation of Lake Winnebago during the storm. Hydrologic analysis was run to assess the effect of the 10-year and 100-year storm events under existing and future land use conditions as well as the effect of the June 10/11, 2004, storm event (under land use and moisture conditions existing at the start of that storm) on Landmark Plaza flooding. This analysis indicates the following: 1. In certain areas, the existing storm sewer system has less than a recommended 10- year design storm capacity under existing conditions. The modeled existing storm sewer system in the Campbell Creek watershed has capacities ranging from 1-year to 100-year. However, certain downstream capacities are realized only because of upstream ponding that attenuates flows getting downstream. 2. Modeling results indicate that the existing 36-inch x 58-inch CMP downstream from Landmark Plaza has limited conveyance capacity because of the high Manning’s “n” values, minimal or reverse slope, and shallow cover. This limited downstream capacity creates a “bottleneck” causing flows to surcharge and inundate upstream areas including Landmark Plaza and appears to be a major factor in the flooding occurring at the Landmark Plaza. Any measures to increase flow rates from Landmark Plaza must also include either improved downstream conveyance or detention to maintain the system capacity. The challenge to upsizing this portion of the storm sewer will be dealing with cover issues and utility conflicts. 3. It appears that the low elevation at which Landmark Plaza was built is a major contributing factor to the flooding problems that are presently occurring. This is evidenced by the fact that the first floor elevation of the eastern Landmark Plaza building (762.28) is only approximately 0.41 feet above the lowest overflow elevation of 761.87 (located on the east side of Westfield Drive) that would allow stormwater from the Landmark Property to discharge into the Tippler Athletic Field. As described in more detail in Section 4.01, we would recommend a minimum of 1.5 feet of freeboard (with 2 feet being desirable) from the first floor elevation of a building to the computed 100-year water surface elevation adjacent to the building. 4. Modeling results indicate that Sawyer Creek did not back up into Landmark Plaza as was originally theorized during the June 10/11, 2004, storm event. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Executive Summary Prepared by Strand Associates, Inc.® ES-3 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\ES.doc\052506 5. There are three diversion/cross connection points along Washburn Street/USH 41 that allow flows to move into and out of adjacent basins as shown in Figure 3.02-2. Diversion Point 1 is south of the Dickinson Avenue/Washburn Street intersection, Diversion Point 2 is just west of Landmark Plaza, and Diversion Point 3 is north of Witzel Avenue. These three diversion/cross connection points appear to have been naturally occurring drainage routes prior to development occurring in these locations. Diverting additional flows toward Sawyer Creek and thus away from the Landmark Plaza at Diversion Point 2 appears feasible only if the storm sewer leading from just north of Witzel Avenue to the Sawyer Creek/Washburn Street outfall is upsized to maintain the existing 100-year capacity of that segment of storm sewer. Diversion of additional flow to the east to reduce flooding along Washburn Street at Diversion Point 1 appears to be feasible, provided it is routed to the proposed Armory detention pond. 6. The capacity of the existing ditch and connecting storm sewer culvert through Landmark Plaza are currently limited by backwater caused by the downstream drainage system. In general, if the downstream “bottleneck” and associated backwater are reduced/relieved, then modeling results indicate that these ditch segments and connecting storm sewer culvert appear to be able to pass the 100-year 2-hour duration storm event flows around the west and south sides of the southern Landmark Plaza building and the movie theater building without inundating these buildings. 7. Modeling results indicate that the areas west and southwest of the eastern Landmark Plaza building have adequate overland flow routes that would convey flows around the north and south sides of the building rather than flood the building if the downstream drainage system capacity is increased. However, the three stormwater inlets on the west and southwest sides of the eastern Landmark Plaza building would experience parking lot surface ponding ranging in depth from 11.8 inches up to 15.5 inches before overflowing along these routes. We would normally recommend no more than 6 to 9 inches of ponding to avoid damage to vehicles at low points. We recommend that the owner of Landmark Plaza perform a study to determine how to reduce potential ponding at the three stormwater inlets to an acceptable level considering that downstream backwater effects are alleviated. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Executive Summary Prepared by Strand Associates, Inc.® ES-4 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\ES.doc\052506 ES.04 ALTERNATIVES ANALYSIS To identify the most cost-effective solution to address the goals of this study, the eleven individual alternatives described in Table 4.13-1 were evaluated. These alternatives were ranked in terms of flooding at Landmark Plaza and flooding watershed-wide. The following criteria were used to arrive at a recommendation after assessment of these eleven alternatives. This included selection of the lowest cost alternative that meets the following criteria: 1. Meets Landmark Plaza Flooding Criteria (2 feet or greater freeboard = Alternatives 3, 6, 7, 8, 9, 10, and 11; and 1.5 to 2 feet freeboard = Alternative 2). 2. Meets Tippler Flooding Criteria (2 feet or greater freeboard = Alternatives 3, 6, 7, 8, 9, 10, and 11; 1.5 to 2 feet freeboard = Alternatives 2). 3. Is in the top six for watershed-wide benefit (Alternatives 3, 7, 8, 9, 10, and 11). 4. Keeps the increased peak discharge at the Sawyer Creek/Washburn outfall to a minimum (Alternatives 7, 9, and 11). See Table 4.13-4. 5. Maximizes use of the ponds considered under these alternatives. See Table 4.13-5. Alt. Alternative Description Landmark Plaza Benefit Rank Watershed- Wide Benefit Rank Avg. Rank Meets Landmark Plaza Criteria Opinion of Probable Cost 1 Detention at Four Locations 9 8 8 No $7,394,200 2 Increase Conveyance Capacity in North Branch System 8 11 9 Yes $2,899,000 3 Flow Diversion Modification 5 3 4 Yes $16,213,600 4 Stormwater Pump Station at Downstream End of Campbell Creek 11 10 11 No $2,682,600 5 Original Mix of Project Components 10 9 10 No $5,581,500 6 Alternative 6 3 7 6 Yes $8,430,600 7 Alternative 7 4 6 5 Yes $7,463,900 8 Alternative 8 1 1 1 Yes $16,030,800 9 Alternative 9 6 2 3 Yes $14,831,600 10 Alternative 10 2 4 2 Yes $14,892,900 11 Alternative 11 7 5 7 Yes $13,693,700 Note: Component 2c ($82,400) would be a Landmark Plaza property owner cost but is included in the costs for Alt. 2 in this table. Table ES 04-1 Summary of Alternatives (Including Land Acquisition Costs and 25 Percent Engineering and Contingency) City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Executive Summary Prepared by Strand Associates, Inc.® ES-5 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\ES.doc\052506 For the purposes of this assessment, Alternatives 1, 4, and 5 are not considered feasible because they do not meet the Landmark Plaza freeboard criteria so they are not included in Table 4.13-4 or Table 4.13-5. The lowest cost alternative meeting the selection criteria is Alternative 7. However, we feel that after implementation of the components of Alternative 7, the City may want to consider providing 120 acre-feet or more of detention at the Westhaven Golf Course or upstream of W. 20th Avenue to deal with persistent flooding problems along W. Washburn Street between W. 20th Avenue and W. 9th Avenue and southeast of Allerton Drive. The high cost to get stormwater to and build detention at the Westhaven Golf Course would be offset by the benefit in reducing actual flood damage costs and is a deterrent to providing this 120 acre-feet of detention. Detention upstream of W. 20th Avenue may be more readily accessible, thus decreasing the cost of providing this detention ES.05 CONCLUSIONS AND RECOMMENDATIONS The recommended stormwater management plan is described in Table ES.05-1. Component Description Opinion of Probable Cost Implementation Schedule and Funding Source Alternative 7 7a Expanded Detention at Tippler Junior High Property $1,783,100 UNPS or MFC grant 7d Storm Sewer System Improvements from Landmark Plaza to Tippler Junior High Detention $408,800 MFC grant 7b Expanded Armory Detention and Upsizing of Storm Sewer Across USH 41 $3,459,700 -Project already in Capital Improvement Plan – MFC or UNPS grant -Doesn’t include cost of removing existing earthen hill on the site 7c Detention at Vacant Lot Southwest of 9th/Washburn Intersection $1,812,300 UNPS or MFC grant TOTAL $7,463,900 Note: Costs do not include utility conflict resolution. Table ES.05-1 Stormwater Plan Components and Implementation Plan (Costs include 25 Percent Engineering and Contingency) In addition to our recommended stormwater management plan, we suggest these recommendations be followed during implementation of the plan: 1. The City should complete soils investigation to determine soil characteristics in locations where detention ponds are proposed. 2. The City should adopt the Policies and Practices identified in Section 5.05 and the Drainage Evaluation Form in Appendix B. 3. The City should coordinate detention basins recommended in this study with detention basins recommended in the water quality study being performed by another consultant. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Executive Summary Prepared by Strand Associates, Inc.® ES-6 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\ES.doc\052506 4. The City should investigate funding opportunities for the detention basins through the Wisconsin Department of Natural Resources (DNR) Municipal Flood Control Grant program and Urban Nonpoint Source and Stormwater Grant program. The DNR Lake Protection Grant program, River Protection Grant program, and Stewardship Grant program should also be explored. 5. The City should update City stormwater facility maps using the field survey forms and survey information provided by Strand Associates. 6. The City should further explore the regulatory requirements with the WI DNR regarding permitting of the off-line pond for the Armory Detention Basin project. 7. The City should investigate possible utility conflicts and space availability for each component of the recommended Alternative. 8. The City should survey the existing earthen hill at the expanded Armory detention basin site and add the cost for removal to the cost of Alternative 7. 9. The owner of Landmark Plaza should perform a study to determine how to reduce potential ponding at nodes 06-846, 06,847, and 06-1293.2 to an acceptable level considering that downstream backwater effects are alleviated as discussed in Section 3.02 C. 7. 10. At the City’s discretion, after implementation of the components of Alternative 7, the City may want to consider providing approximately 120 acre-feet of detention at the Westhaven Golf Course or upstream of W. 20th Avenue. As discussed above, providing this detention upstream of W. 20th Avenue may be more cost beneficial to accomplish. 11. We recommend that the City assess inlet capacity in conjunction with future street improvement projects to evaluate the benefits of adding inlets to fully realize the capacities shown in Figure 4.14-1. 12. The City should consider upsizing the storm conveyance facilities shown in Figure 4.15- 1 as funds become available, as reconstruction becomes necessary and as feasible after implementation of Alternative 7. SECTION 1 INTRODUCTION City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 1–Introduction Prepared by Strand Associates, Inc.® 1-1 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S1.doc\052606 1.01 INTRODUCTION This report summarizes the methodology and results of a study done by Strand Associates, Inc. to develop a stormwater management plan for the North Branch of Campbell Creek Watershed in the City of Oshkosh. The North Branch Campbell Creek Watershed is predominantly a fully developed urban watershed that joins with the South Branch of Campbell Creek at West 4th Avenue and Sawyer Street. The North Branch of Campbell Creek and specifically the Landmark Plaza have experienced recent flooding. A sampling of photographs taken by City staff on June 11, 2004, documenting the flooding that occurred as a result of a June 10/11, 2004, storm event is included in Appendix A. Much of the development in this watershed occurred prior to the advent and implementation of strong guidelines on stormwater management, resulting in several areas with stormwater system capacity issues. This stormwater management plan, in conjunction with previous stormwater studies, will address ways to mitigate the existing stormwater flooding problems in the North Branch of Campbell Creek watershed and suggest ways to decrease the impacts of future development. The following tasks were performed: 1. Evaluate alternatives to reduce flooding in the North Branch Campbell Creek Watershed. 2. Evaluate specific alternatives to reduce flooding at the Landmark Plaza shopping center. 3. Perform field survey of stormwater conveyance facilities surrounding the Landmark Plaza shopping center as well as at other critical locations. 4. Set up a hydraulic model of the stormwater conveyance system that will allow for assessment of existing and potential diversions to Sawyer Creek, inclusion of the Armory and Wal-Mart detention basins (based on existing information), inclusion of the proposed Campbell Creek Detention Basins Phase I and II at the Menard’s/Armory site, and inclusion of the Westhaven Golf Club detention (based on existing information). 1.02 SCOPE OF STUDY This study included the following key elements: A. Topographic Survey A field survey was completed to provide vertical elevation and horizontal location of various portions of the storm sewer system including storm sewer and ditches along USH 41/Washburn Street. In addition, mapping data was obtained from previous work in the watershed. Mapping used for this study is discussed in Section 2 and shown in Figure 2.01-1. The field survey forms and survey information have been provided to the City of Oshkosh for use in updating the City’s Geographical Information System (GIS). . City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 1–Introduction Prepared by Strand Associates, Inc.® 1-2 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S1.doc\052606 B. Storm Sewer System Map A storm sewer system map was developed for the Campbell Creek Watershed with the mapping focusing on the North Branch system. This map is shown in Figure 2.01-1 attached at the back of this report C. Analysis of Existing Drainage System The existing stormwater drainage system was analyzed with the XP-SWMMTM computer model. Portions of the South Branch and Main Branch were modeled along with the mainline in the North Branch. This model was developed to estimate the peak discharge rates and runoff volumes during storm events under existing land use conditions. The model was also used to identify available capacities of existing storm sewers and detention basins. This analysis identified areas currently vulnerable to flooding during extreme storm events. D. Analysis of Potential Impacts of Future Development on Existing Drainage Systems The XP-SWWMTM model was used to determine locations where improvements to the existing drainage system will accommodate future development and mitigate the associated stormwater impacts under future land use conditions. E. Policies and Practices A set of policies and guidance for responding to and documenting existing drainage issues was developed and is included in Section 5 along with a Drainage Evaluation Form in Appendix B. F. Stormwater Management Plan This project report includes recommendations based on an alternatives analysis. Discussion of project components is also included in the report. Opinions of Probable Cost for each conceptual alternative are included. All costs are presented in 2nd quarter 2006 dollars. Future construction costs should be adjusted for inflation when final project schedules are determined. G. Implementation Plan The implementation plan includes the development of a schedule for completion of recommended improvements and a discussion of financing options for the recommended stormwater improvements. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 1–Introduction Prepared by Strand Associates, Inc.® 1-3 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S1.doc\052606 1.03 LOCATION OF STUDY AREA The Campbell Creek watershed in an area east of South Oakwood Road, north of W. 20th Avenue, west of the Fox River, and south of Taft Avenue. The North Branch is in the northwest portion of this area. The location of the study area, which is in the Upper Fox River Basin, also is shown in Figure 1.03-1 and is located in the Upper Fox River Basin. Figure 1.03-1 Study Area Location Relative to DNR Watersheds 1.04 OTHER SIMILAR STUDIES The following reports/plans are applicable to portions of the North Branch Campbell Creek planning area. Stormwater Management Plan–Campbell Creek Watershed, Prepared for City of Oshkosh, HNTB, December 1994. Citywide Storm Water Management Study, Prepared for City of Oshkosh, Mead & Hunt, March 2000. Stormwater Management Revenue Alternatives Phase I Feasibility Analysis, Tetra Tech MPS/Mead & Hunt, August 2000. Winnebago County Land and Water Resource Management Plan, 1998. The State of the Upper Fox River Basin, Wisconsin Department of Natural Resources (DNR), WT-665- 2001, October 2001. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 1–Introduction Prepared by Strand Associates, Inc.® 1-4 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S1.doc\052606 1.05 APPLICABLE STANDARDS AND DESIGN CRITERIA Land development in the City of Oshkosh is regulated by City ordinances as well as by state statutes. The design criteria used in this report are intended to meet these ordinances. A. City of Oshkosh Ordinances Land-disturbing and land development activities in the City of Oshkosh are regulated by the following City of Oshkosh ordinances regarding stormwater and erosion control: 1. Chapter 24–Wastewater Systems and Storm Drainage. In terms of ordinance requirements affecting flooding, Section 24-10 Storm Drainage Requirements (D) reads: “The peak runoff rate from a 10-year and a 100-year storm after development shall not exceed predevelopment runoff peaks, which would have resulted from storms with 24-hour durations and a recurrence interval of 10 years.” 2. Chapter 30 (39–67)–Floodplain Zoning Ordinance. 3. Chapter 30 (69-75)–Land Subdivision Ordinance. 4. Storm Sewer Sizing Requirements–According to City staff, the City requires installation of storm sewers designed for a 10-year storm event as required by the Wisconsin Department of Transportation (WisDOT) Facilities Development Manual (FDM) for new subdivisions as well as a route for safe passage of the 100-year storm event. B. State of Wisconsin–NR 151 Development activities are also regulated by Wisconsin Department of Natural Resources (DNR) NR 151, which applies to new development and redevelopment that has 1 acre or more of land- disturbing construction activity. NR 151 has stormwater and erosion control requirements falling under the following general categories. The full NR 151 code can be found at: http://www.legis.state.wi.us/rsb/code/nr/nr151.pdf In addition, the DNR Wet Detention Basin standard, which is used to comply with the detention standards of NR 151 is available at the following website. http://www.dnr.state.wi.us/org/water/wm/nps/stormwater/techstds.htm 1. Erosion Control (Construction Site Performance Standards) ƒ Implement Best Management Practices (BMPs) to reduce the sediment load carried to runoff by 80 percent. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 1–Introduction Prepared by Strand Associates, Inc.® 1-5 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S1.doc\052606 ƒ Minimize tracking of sediment from the construction site onto roads and other paved surfaces. ƒ Minimize the discharge of sediment as part of site dewatering. ƒ Protect separate storm drain inlet structures from receiving sediment. 2. Stormwater (Postconstruction Site Performance Standards) ƒ Total Suspended Solids Reduction of 80 percent for new development and 40 percent for redevelopment. ƒ Peak discharge control for the 2-year storm as follows. “By design, BMPs shall be employed to maintain or reduce the peak runoff discharge rates, to the maximum extent practicable, as compared to pre-development conditions for the 2-year, 24-hour design storm applicable to the post-construction site…”. ƒ Infiltration. ƒ Protective Areas. ƒ Fueling and Maintenance Areas. C. Winnebago County Ordinances The Winnebago County stormwater and erosion control ordinances, as written, require all developments regardless of amount of land disturbance or amount of impervious area created to comply with the Winnebago County stormwater ordinance. Through our ongoing discussions with the County regarding applicability of the County ordinance on projects in the Town of Omro, we have obtained further clarification on impervious area thresholds as follows. ƒ Stormwater Plan/Permit Required: 1,000 square feet of commercial building/parking lot impervious area AND/OR 1,000 square feet or greater residential out building. ƒ Erosion Control Plan/Permit Required: 4,000 square feet of agricultural impervious area (but doesn’t require a stormwater plan/permit). Currently, the City is administering its own stormwater and erosion control requirements independent of Winnebago County. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 1–Introduction Prepared by Strand Associates, Inc.® 1-6 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S1.doc\052606 1.06 PHASE II STORMWATER PERMIT The City of Oshkosh will be covered under the Wisconsin Pollutant Discharge Elimination System (WPDES) Phase II Stormwater Permit program upon issuance of the permit. This general permit, WPDES Permit No. WI-S050075-1, has been signed/issued and became effective on January 19, 2006. In early March 2006, the City received a letter indicating that the City is now under this permit and has 90 days to complete the Notice of Intent to Apply for Coverage Under MS4 General Permit form and submit it to the DNR. This submittal requires a summary of measurable goals, management programs, and practices that they will be implementing to comply with the MS4 general permit. After a submittal by the City, the DNR will review submittals and post on web site. This will lead to authorization of coverage under the general permit in the summer of 2006. The permit compliance schedule then allows between 12 and 48 months to develop and implement program activities. The permit will have requirements under the following items. 1. Public Information and Education 2. Public Involvement and Participation 3. Illicit Discharge Detection and Elimination 4. Construction Site Pollution Control 5. Postconstruction Site Stormwater Management 6. Pollution Prevention 7. Storm Sewer System Map The City is currently undertaking this effort under a separate project. 1.07 DEFINITIONS AND ABBREVIATIONS The following definitions and abbreviations are presented as an aid to the reader. A. Definitions Average Sediment Depth–The average depth of deposited sediment measured over the entire pond area. Average Current Normal Pool Depth–The average depth of water measured over the entire pond area. This is the difference between the water surface and the top of sediment. Average Current Total Pond Depth–The average depth of the pond if all deposited sediment were removed. This is the difference between the water surface and the existing bottom of the pond. Control Structure–The manmade structure that controls the water released from a stormwater facility to the outfall. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 1–Introduction Prepared by Strand Associates, Inc.® 1-7 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S1.doc\052606 Curve Number–The Soil Conservation Service has devised a method of computing the runoff from an area based on a system of curve numbers. The curve number for an area of land is obtained by examining the land use and soil type of the land area. Flume–The structure or channel upstream of the stormwater facility used to convey stormwater to the facility. Forebay–The area of the pond near the inlet where heavy sediments are encouraged to settle out of the stormwater that enters a facility. Outfall–The piping, channel, or other equipment downstream of the control structure used to transfer water out of the control structure to the surrounding environment. Recurrence Interval–The probability that a given rainfall event will occur in a given year. For example, a 100-year rainfall event has a 1 percent chance of occurring in a given year (1/100 = 0.01 = 1 percent), a 5-year rainfall event has a 20 percent chance of occurring in a given year (1/5 = 0.20 = 20 percent). Subbasin–The parts of a drainage basin that, when combined, create the entire drainage basin for a facility. Time of Concentration (Tc)–“… the time for runoff to travel from the hydraulically most distant point of the watershed to a point of interest within the watershed,” SCS, 1986. Time Distribution of Rainfall–The amount of rainfall that has fallen during a storm event versus the amount of time that has elapsed during a storm event. Weir–A wall spanning the control structure. When the water level of the pond reaches the top of the weir, water flows over the weir and out of the pond. B. Abbreviations ac - acres ac-ft - acre feet BMP - Best Management Practices cfs - cubic feet per second CMP - corrugated metal pipe DNR - Wisconsin Department of Natural Resources FDM - Facilities Development Manual FEMA - Federal Emergency Management Agency HSG - Hydrologic Soils Groups ft - feet GIS - Geographic Information System MRCC - Midwestern Regional Climate Center NGVD - National Geodetic Vertical Datum City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 1–Introduction Prepared by Strand Associates, Inc.® 1-8 JHL:pll\\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S1.doc\052606 NHI - National Heritage Inventory NOI - Notice of Intent NRCS - National Resource Conservation Service RCP - reinforced concrete pipe RCN - runoff curve number SCS - Soil Conservation Service sq mi - square miles Tc - time of concentration TIN - triangulated irregular network TSS - total suspended solids USACE - United States Army Corps of Engineers USGS - United States Geological Survey WisDOT - Wisconsin Department of Transportation WPDES - Wisconsin Pollutant Discharge Elimination System WWTP - wastewater treatment plant SECTION 2 CONTRIBUTING WATERSHED CHARACTERISTICS City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® 2-1 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S2.doc\052506 2.01 BASIN CHARACTERISTICS AFFECTING STORMWATER RUNOFF A. General The amount of stormwater discharging from a watershed depends on a number of individual characteristics. Watershed size and topography, land use, soil types and degree of saturation, type of drainage system (storm sewers, open channels), and amount of watershed storage available all affect stormwater discharge. To quantify stormwater flows and volumes, an inventory of watershed physical characteristics in the Campbell Creek watershed was completed. This section describes physical land characteristics in the Campbell Creek watershed that impact stormwater runoff. B. Drainage Patterns Existing drainage patterns, watershed designations, and locations and sizes of storm sewer and other water features are identified in Figure 2.01-1 attached at the back of this report. The Campbell Creek watershed draining approximately 1,840 acres is located west of the Fox River and south of Lake Butte des Morts and includes lands currently in the City of Oshkosh, Town of Algoma, and Town of Nekimi. The portion of the City being studied with this plan drains in four general manners. The northernmost portion referred to as the North Branch of Campbell Creek (NBB-xx basin id designations) drains an area of approximately 140 acres east of USH 41 including Landmark Plaza lands prior to draining east through the storm sewer system. The southernmost portion referred to as the South Branch of Campbell Creek (SBB-xx basin id designations) drains a total of 1,000 acres. Of this total, approximately 665 acres of land west of USH 41 and then drains either northerly towards Sawyer Creek via a WisDOT ditch or easterly through the Armory area before joining up with the North Branch near the intersection of Glen Avenue and Mason Street. The joined North and South Branch systems continue easterly to a backwater of the Fox River through the Main Stem watershed (CCB-xx basin id designations) that drains approximately 225 acres. The Fox River then discharges into Lake Winnebago prior to draining northeasterly to Green Bay and Lake Michigan. A portion of the Sawyer Creek watershed (SCB-xx basin id designations) is interconnected with the North Branch and South Branch systems allowing approximately 475 acres of drainage to impact drainage patterns in the Campbell Creek watershed. Upstream stormwater flows are able to enter Landmark Plaza through a 3-foot x 4.5-foot reinforced concrete pipe (RCP) Box starting in the ditch at the west side of USH 41 that discharges into the ditch that runs on the south side of Landmark Plaza. At the southeast corner of Landmark Plaza, the ditch enters the storm sewer system and heads north toward the center of the east side of Landmark Plaza before heading east to the Campbell Creek outfall in a 36-inch x 58-inch corrugated metal pipe (CMP) at an approximate average slope of 0.232 percent. The Fox River through Oshkosh and Lake Winnebago are both identified by the DNR as impaired waters and are on the 303(d) list. Impaired waters are those that are not meeting the state’s water quality standards. More information on the 303 (d) list can be found on the DNR’s Web site at: http://dnr.wi.gov/org/water/wm/wqs/303d/303d.html. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® 2-2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S2.doc\052506 C. Soils The amount of stormwater runoff produced by a storm event is impacted by the types of soil underlying the watershed. Soils having a high percentage of sand and gravel will absorb a higher percentage of stormwater runoff than will soils having high clay content. This means that sandy soil generally produces less runoff than clay soil. The Natural Resource Conservation Service (NRCS) classifies soil types in categories known as Hydrologic Soil Groups (HSG). Group A soils consist of sandy soils having high infiltration rates and low runoff potential. Group B soils have moderately fine to moderately coarse textures and moderate runoff potential. Group C soils are typically sandy clay loam soils having moderately fine to fine textures and a low infiltration capacity. Examples of Group D soils are clays, soils with a permanent high water table, and shallow soils over nearly impervious material. Group D soils have a very low infiltration capacity and have high runoff potential. HSG Percent of Watershed A 0.5% B 0.4% B/D 2.0% C 95.2% D 1.8% Table 2.01-1 Hydrologic Soil Groups (HSG) Soil types, hydrologic soil group, and expected soil permeability at 36-inch depth in the Campbell Creek Watershed are identified in Table 2.01-2 and illustrated in Figure 2.01-2. According to the Winnebago County, Wisconsin, Soils Survey, published by the U.S. Department of Agriculture in cooperation with the Research Division of the College of Agricultural and Life Sciences, University of Wisconsin, local soils are primarily silt loams and silty clay loams. These soils are classified by the NRCS as mainly HSG Group C soils. Infiltration rates for the Group B soils range from 0.15 to 0.30 inches per hour. Infiltration rates for the Group C soils range from 0.05 to 0.15 inches per hour. Infiltration rates for Group A soils are generally greater than 0.30 inches per hour. The percentages of each hydrologic soil group in the watershed are shown in Table 2.01-1. According to the NRCS Soil Survey for Winnebago County, the predominant soil type in the Campbell Creek watershed belongs to the Kewaunee Silt Loam series. These are well drained and moderately well-drained soils on convex hills and lower side slopes with a silt loam surface layer, a firm clay subsoil, and a firm silty clay loam substratum. SOILS MAP NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 2.01-21-382.021 Taft Ave Knapp St W. South Park Ave US HWY 41 ST HWY 44 W 20th Ave S Oakwood Rd W 9th Ave Witzel Ave US HWY 41 City of Oshkosh Town of Algoma City of Oshkosh Town of Algoma Town of Nekimi Town of Nekimi City of Oshkosh Town of Algoma FOX RIVER CAMPBELL CREEK Town of Nekimi Town of Algoma SBB-60 SCB-75 CCB-10 SBB-15 SBB-25 SCB-35 SCB-85 CCB-05 SCB-70 SCB-50 SCB-10 NBB-30 CCB-20 SBB-55 NBB-20 SBB-45 SCB-15 SBB-50 SBB-30NBB-15 SBB-10 SCB-30 SCB-55 SBB-20 SCB-20 NBB-55 SBB-05 SBB-41 CCB-15 NBB-10 SCB-25 SCB-80 SBB-40 SCB-40 SCB-60 SBB-35 NBB-45 SCB-65 NBB-25 SBB-42 NBB-05 SCB-05 NBB-40NBB-35 NBB-50 SCB-45 S:\@SAI\351--400\382\021\GIS\Report Figures\Soils.mxd 0 1,500 3,000 750 Feet Legend Municipal Boundary Existing Drainage Basins Hydrologic Soils Group A B B/D C D City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® 2-3 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S2.doc\052506 Symbol Soil Description Permeability at 36 inches (in/hr) HSG1 Percent of Watershed HmB Hochheim loam, 2-6% slopes Gently sloping, well drained soils on broad crests of hills and ridges on till plains; loam surface layer; friable loam subsoil; gravelly fine sandy loam substratum. 0.2-2.0 B 0.4% HrB Hortonville silt loam, 2-6% slopes Gently sloping, well drained soils on convex hills and lower side slopes on till plains; silt loam surface layer; friable loam subsoil; friable loam substratum 0.2-2.0 C 0.5% KnB Kewaunee silt loam, 2-6% slopes Gently sloping, well drained and moderately well drained soil is on convex hills and lower side slopes; silt loam surface layer; firm clay subsoil; firm silty clay loam substratum. 0.06-0.6 C 54.1% KoC2 Kewaunee silt loam, 6-12% slopes Sloping, well drained soil on sides of moraines and hills; silty clay loam surface layer; firm clay subsoil; firm silty clay loam substratum. 0.06-0.6 C 2.3% LzB Lorenzo Variant loam, 2-8% slopes Gently sloping, moderately well drained soil on till plains; loam surface layer; upper part of subsoil is friable caly loam; lower part of subsoil is friable gravelly sandy loam; very gravelly loamy sand substratum. 0.06-0.6 C 3.1% MaA Manawa silty clay loam, 0- 3% slopes Nearly level to gently sloping, somewhat poorly drained soil in drainageways and depressional areas; silty clay loam surface layer; upper part of subsoil is firm silty clay loam; lower part of subsoil and substratum is firm silty clay. 0.06-0.2 C 21.4% MtA Mosel silt loam, 0-3% slopes Nearly level to gently sloping, somewhat poorly drained soil on valley terraces and in drainageways and swales in uplands; silt loam surface layer; friable silt loam subsurface layer; upper part subsoil is friable clay loam; lower part subsoil is firm silty clay; firm silty clay substratum 0.06-0.6 C 2.9% Na Navan silt loam Nearly level, poorly drained soil in drainageways and swales in the uplands; silt loam surface layer; upper subsoil is friable silt loam; lower subsoil is firm clay loam; firm silty clay substratum. 0.6-2.0 D 0.7% OmB Omro clay loam, 2-6% slopes Gently sloping, well drained soil is on crests and sides of broad hills; clay loam surface layer; upper subsoil is firm clay; lower subsoil is firm silty clay; friable gravelly fine sandy loam substratum. 0.06-0.6 C 4.5% Pg Pits, gravel Excavation pits from which sand and gravel have been removed. NA A 0.5% Pu Poygan silty clay loam Nearly level, poorly drained soil in drainageways and depressional areas; silty clay loam surface area; firm silty clay subsoil; firm silty clay substratum. 0.06-0.2 D 1.2% UoA Udorthents, 0-3% slopes Nearly level to gently sloping, moderately well drained to somewhat poorly drained soils adjacent to major drainageways and lakes; 1 to 4 feet of fill material over poorly drained soils; fill material is commonly clay, silty clay, silty clay loam and clay loam containing pebbles and stones; buried soil is mineral or organic. NA C 6.5% We Wauseon silt loam Nearly level, poorly drained soil in drainageways and swales in the uplands; silt loam surface layer; upper subsoil is friable silt loam; middle and lower subsoil is friable fine sandy loam; firm silty clay loam substratum. <0.6 B/D 2.0% 1 HSG = Hydrologic soils group Table 2.01-2 Campbell Creek Watershed Soils City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® 2-4 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S2.doc\052506 E. Land Use Land use is another factor that affects the amount of stormwater runoff that will be produced by a rainstorm. Urbanization and development reduce the ability of the ground to absorb stormwater, typically causing peak discharges and runoff volumes to increase. The time from the beginning of the storm event to the occurrence of the peak runoff may also be significantly shortened. Existing and future land use in the Campbell Creek watershed is shown in Figures 2.01-3 and 2.01-4. Existing land use is based on the City’s impervious area GIS layer supplemented with review of aerial information provided by Winnebago County. See Figure 2.01-5 for a graphic of the different types of existing landuse according to the City’s Smart Growth Plan. Future land use is also based on the City’s impervious area GIS layer as shown in Figure 2.01-4 and is supplemented with land use from the 20-Year Land Use Plan (Smart Growth Plan) shown in Figure 2.01-6 for areas currently not developed. This investigation indicates that the watershed is currently almost entirely built out except for agricultural lands in the southwestern portion of the watershed and various vacant parcels of land in the urbanized central portion of the watershed. The City of Oshkosh Stormwater Ordinance (Chapter 24) in conjunction with NR 151 regulates future development (over 1 acre in size). Future land use will likely increase future stormwater volumes due to the increase in impervious area. We have also included a zoning map from the City Smart Growth Plan in Figure 2.01-7. Table 2.01-3 and 2.01-4 summarize the existing and future hydrologic parameters for each drainage basin, respectively. These tables show that the impervious area increases approximately 10 percent between existing and future land use conditions. 2.02 EXPECTED PRECIPITATION DEPTHS According to the Midwestern Regional Climate Center (MRCC) Web site, the City of Oshkosh receives an average annual precipitation of 31.57 inches. Significant runoff-producing events typically occur during spring and summer thunderstorms as a result of stormwater runoff from short-duration, intense storm events. The depth and duration of rainfall in a watershed for a given storm event has a major impact on the amount of stormwater runoff produced. Table 2.02-1 summarizes expected rainfall depths for the 1-year through 100-year storm frequencies for the region (Bulletin 71, Rainfall Atlas of the Midwest, Floyd A. Huff and James R. Angel–Climatic Section 6). These rainfall totals are used in conjunction with the Huff distribution to estimate peak storm discharges. Storm Duration (hours) Frequency (yr) 1 2 3 6 12 18 24 1 0.92 1.14 1.25 1.47 1.71 1.84 1.96 2 1.13 1.39 1.54 1.80 2.09 2.26 2.40 5 1.41 1.74 1.92 2.25 2.61 2.82 3.00 10 1.67 2.06 2.28 2.67 3.10 3.35 3.56 25 2.10 2.59 2.85 3.35 3.88 4.19 4.46 50 2.50 3.09 3.40 3.99 4.63 5.00 5.32 100 2.98 3.68 4.06 4.76 5.52 5.97 6.35 Table 2.02-1 Design Storm Rainfall Depths, Bulletin 71 EXISTING LAND USE - IMPERVIOUS AREA MAP NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 2.01-31-382.021 Taft Ave Knapp St W. South Park Ave US HWY 41 ST HWY 44 W 20th Ave S Oakwood Rd W 9th Ave Witzel Ave US HWY 41 City of Oshkosh Town of Algoma City of Oshkosh Town of Algoma Town of Nekimi Town of Nekimi City of Oshkosh Town of Algoma FOX RIVER CAMPBELL CREEK Town of Nekimi Town of Algoma SBB-60 SCB-75 CCB-10 SBB-15 SBB-25 SCB-35 SCB-85 CCB-05 SCB-70 SCB-50 SCB-10 NBB-30 CCB-20 SBB-55 NBB-20 SBB-45 SCB-15 SBB-50 SBB-30NBB-15 SBB-10 SCB-30 SCB-55 SBB-20 SCB-20 NBB-55 SBB-05 SBB-41 CCB-15 NBB-10 SCB-25 SCB-80 SBB-40 SCB-40 SCB-60 SBB-35 NBB-45 SCB-65 NBB-25 SBB-42 NBB-05 SCB-05 NBB-40NBB-35 NBB-50 SCB-45 S:\@SAI\351--400\382\021\GIS\Report Figures\Impervious Areas .mxd 0 1,500 3,000 750 Feet Legend Municipal Boundary Existing Drainage Basins Impervious Area Pervious Area (Non-Agriculture) Pervious Area (Agriculture) Minor ROW Major ROW DOT ROW FUTURE LAND USE - IMPERVIOUS AREA MAP NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 2.01-41-382.021 Taft Ave Knapp St W. South Park Ave US HWY 41 ST HWY 44 W 20th Ave S Oakwood Rd W 9th Ave Witzel Ave US HWY 41 City of Oshkosh Town of Algoma City of Oshkosh Town of Algoma Town of Nekimi Town of Nekimi City of Oshkosh Town of Algoma FOX RIVER CAMPBELL CREEK Town of Nekimi Town of Algoma SBB-60 SCB-75 CCB-10 SBB-15 SBB-25 SCB-35 SCB-85 CCB-05 SCB-70 SCB-50 SCB-10 NBB-30 CCB-20 SBB-55 NBB-20 SBB-45 SCB-15 SBB-50 SBB-30NBB-15 SBB-10 SCB-30 SCB-55 SBB-20 SCB-20 NBB-55 SBB-05 SBB-41 CCB-15 NBB-10 SCB-25 SCB-80 SBB-40 SCB-40 SCB-60 SBB-35 NBB-45 SCB-65 NBB-25 SBB-42 NBB-05 SCB-05 NBB-40NBB-35 NBB-50 SCB-45 S:\@SAI\351--400\382\021\GIS\Report Figures\Future Impervious Areas.mxd 0 1,500 3,000 750 Feet Legend Municipal Boundary Existing Drainage Basins Impervious Area Pervious Area (Non-Agriculture) Pervious Area (Agriculture) Minor ROW Major ROW DOT ROW Industrial Residential Commercial EXISTING LAND USE MAP - SMART GROWTH PLAN NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 2.01-51-382.021 Taft Ave Knapp St W. South Park Ave US HWY 41 ST HWY 44 W 20th Ave S Oakwood Rd W 9th Ave Witzel Ave US HWY 41 City of Oshkosh Town of Algoma City of Oshkosh Town of Algoma Town of Nekimi Town of Nekimi City of Oshkosh Town of Algoma FOX RIVER CAMPBELL CREEK Town of Nekimi Town of Algoma City of Oshkosh SBB-60 SCB-75 CCB-10 SBB-15 SBB-25 SCB-35 SCB-85 CCB-05 SCB-70 SCB-50 SCB-10 NBB-30 CCB-20 SBB-55 NBB-20 SBB-45 SCB-15 SBB-50 SBB-30NBB-15 SBB-10 SCB-30 SCB-55 SBB-20 SCB-20 NBB-55 SBB-05 SBB-41 CCB-15 NBB-10 SCB-25 SCB-80 SBB-40 SCB-40 SCB-60 SBB-35 NBB-45 SCB-65 NBB-25 SBB-42 NBB-05 SCB-05 NBB-40NBB-35 NBB-50 SCB-45 S:\@SAI\351--400\382\021\GIS\Report Figures\Existing Land Use.mxd 0 1,500 3,000 750 Feet Legend Municipal Boundary Existing Drainage Basins Land Use Commercial Industrial Residential Agriculture Government Infill Non-Res Landfill-Quarry Mixed Use Parking Lot Public Park Rec-Open Space School Vacant Land Infrastructure Institutional 20 YEAR LAND USE PLAN - SMART GROWTH PLAN NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 2.01-61-382.021 Taft Ave Knapp St W. South Park Ave US HWY 41 ST HWY 44 W 20th Ave S Oakwood Rd W 9th Ave Witzel Ave US HWY 41 City of Oshkosh Town of Algoma City of Oshkosh Town of Algoma Town of Nekimi Town of Nekimi City of Oshkosh Town of Algoma FOX RIVER CAMPBELL CREEK Town of Nekimi Town of Algoma SBB-60 SCB-75 CCB-10 SBB-15 SBB-25 SCB-35 SCB-85 CCB-05 SCB-70 SCB-50 SCB-10 NBB-30 CCB-20 SBB-55 NBB-20 SBB-45 SCB-15 SBB-50 SBB-30NBB-15 SBB-10 SCB-30 SCB-55 SBB-20 SCB-20 NBB-55 SBB-05 SBB-41 CCB-15 NBB-10 SCB-25 SCB-80 SBB-40 SCB-40 SCB-60 SBB-35 NBB-45 SCB-65 NBB-25 SBB-42 NBB-05 SCB-05 NBB-40NBB-35 NBB-50 SCB-45 S:\@SAI\351--400\382\021\GIS\Report Figures\20 Year Land Use Plan.mxd 0 1,500 3,000 750 Feet Legend Municipal Boundary Existing Drainage Basins 20-Year Land Use Plan Commercial Industrial Pro Public Institution Residential ZONING MAP - SMART GROWTH PLAN NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 2.01-71-382.021 Taft Ave Knapp St W. South Park Ave US HWY 41 ST HWY 44 W 20th Ave S Oakwood Rd W 9th Ave Witzel Ave US HWY 41 City of Oshkosh Town of Algoma City of Oshkosh Town of Algoma Town of Nekimi Town of Nekimi City of Oshkosh Town of Algoma FOX RIVER CAMPBELL CREEK Town of Nekimi Town of Algoma City of Oshkosh SBB-60 SCB-75 CCB-10 SBB-15 SBB-25 SCB-35 SCB-85 CCB-05 SCB-70 SCB-50 SCB-10 NBB-30 CCB-20 SBB-55 NBB-20 SBB-45 SCB-15 SBB-50 SBB-30NBB-15 SBB-10 SCB-30 SCB-55 SBB-20 SCB-20 NBB-55 SBB-05 SBB-41 CCB-15 NBB-10 SCB-25 SCB-80 SBB-40 SCB-40 SCB-60 SBB-35 NBB-45 SCB-65 NBB-25 SBB-42 NBB-05 SCB-05 NBB-40NBB-35 NBB-50 SCB-45 S:\@SAI\351--400\382\021\GIS\Report Figures\Zoning.mxd 0 1,500 3,000 750 Feet Legend Municipal Boundary Existing Drainage Basins TAG C M R T City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® Page 1 of 1 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 2.01-3.doc\052506 TABLE 2.01-3 EXISTING CONDITIONS HYDROLOGIC PARAMETER Basin ID Structure ID Drainage Basin Area (ac) Tc (hrs) Tc (min) Total Impervious Area (ac) Total Pervious Area (ac) Total Pervious Ag. (ac) Pervious % Impervious % Pervious RCN Composite RCN CCB-05 D-OF-3 46.68 0.47 28.2 21.15 25.52 0.00 55% 45% 74 85 CCB-10 Outfall 1 134.37 0.75 45.0 66.46 67.91 0.00 51% 49% 75 86 CCB-15 06-462 15.97 0.32 19.2 5.94 10.03 0.00 63% 37% 74 83 CCB-20 06-602 27.78 0.89 53.4 11.56 16.23 0.00 58% 42% 74 84 Total 224.80 105.12 119.68 0.00 53% 47% NBB-05 06-469 7.00 0.56 33.6 2.87 4.14 0.00 59% 41% 74 84 NBB-10 06-552 14.29 0.44 26.4 6.73 7.57 0.00 53% 47% 75 86 NBB-15 06-653 21.75 0.70 42.0 8.75 13.00 0.00 60% 40% 74 84 NBB-20 06-770 26.03 0.70 42.0 5.51 20.52 0.00 79% 21% 74 79 NBB-25 06-1062 7.08 0.39 23.4 3.61 3.48 0.00 49% 51% 74 86 NBB-30 06-688 29.72 0.34 20.4 17.25 12.47 0.00 42% 58% 76 88 NBB-35 06-843 3.98 0.30 18.0 3.03 0.95 0.00 24% 76% 75 92 NBB-40 06-846 6.08 0.09 5.4 5.02 1.07 0.00 18% 82% 74 94 NBB-45 06-847 4.25 0.08 4.8 4.03 0.22 0.00 5% 95% 74 97 NBB-50 06-1293.2 2.31 0.09 5.4 2.25 0.06 0.00 3% 97% 74 97 NBB-55 LP-5 18.43 0.30 18.0 6.92 11.51 0.00 62% 38% 76 84 Total 140.93 65.96 74.97 0.00 53% 47% SBB-05 06-471 16.63 0.31 18.6 7.03 9.60 0.00 58% 42% 74 84 SBB-10 06-474 20.38 0.62 37.2 7.19 13.20 0.00 65% 35% 74 83 SBB-15 06-473 73.71 0.77 46.2 23.88 49.83 0.00 68% 32% 68 78 SBB-20 AEW-1 19.10 0.54 32.4 7.61 11.50 0.00 60% 40% 74 84 SBB-25 13-420 71.15 0.71 42.6 36.85 34.30 0.00 48% 52% 75 87 SBB-30 13-457 21.87 0.19 11.4 12.62 9.25 0.00 42% 58% 74 88 SBB-35 13-460 4.34 0.33 19.8 2.40 1.94 0.00 45% 55% 75 88 SBB-40 AD-4 9.89 0.63 37.8 0.28 9.61 0.00 97% 3% 74 75 SBB-41 AP-1 16.30 0.36 21.6 4.44 11.87 0.00 73% 27% 74 80 SBB-42 AD-3 6.93 0.13 7.8 2.47 4.45 0.00 64% 36% 74 83 SBB-45 13-1217 24.46 0.18 10.8 20.18 4.29 0.00 18% 82% 74 94 SBB-50 13-1221 23.82 0.13 7.8 18.71 5.11 0.00 21% 79% 75 93 SBB-55 AEW-15 26.46 0.44 26.4 14.84 11.62 0.00 44% 56% 75 88 SBB-60 STR-10 665.20 1.05 63.0 181.59 315.81 167.80 73% 27% 78 83 Total 1000.25 340.09 492.36 167.80 66% 34% SCB-05 16-430 6.18 0.29 17.4 2.89 3.29 0.00 53% 47% 74 85 SCB-10 16-428 30.35 0.53 31.8 15.20 15.15 0.00 50% 50% 74 86 SCB-15 06-640 24.37 0.40 24.0 12.35 12.02 0.00 49% 51% 74 86 SCB-20 06-678 18.95 0.73 43.8 8.81 10.14 0.00 54% 46% 74 85 SCB-25 06-1355 13.72 0.11 6.6 7.53 6.19 0.00 45% 55% 78 89 SCB-30 16-647 20.26 0.83 49.8 5.53 8.52 6.21 73% 27% 79 84 SCB-35 06-773 51.20 0.79 47.4 26.23 24.96 0.00 49% 51% 75 87 SCB-40 40D-19 9.30 1.07 64.2 4.61 4.69 0.00 50% 50% 76 87 SCB-45 40D-17 2.04 0.14 8.4 0.74 1.29 0.00 64% 36% 80 86 SCB-50 WP-1 31.38 0.21 12.6 19.57 11.80 0.00 38% 62% 75 89 SCB-55 40D-12 20.20 0.30 18.0 10.16 10.03 0.00 50% 50% 77 87 SCB-60 13-2371 9.18 0.25 15.0 5.60 3.58 0.00 39% 61% 78 90 SCB-65 40D-7 7.97 0.67 40.2 3.25 4.72 0.00 59% 41% 75 84 SCB-70 13-792 34.92 0.66 39.6 13.95 20.97 0.00 60% 40% 74 84 SCB-75 13-764 133.14 0.71 42.6 40.79 92.35 0.00 69% 31% 74 81 SCB-80 13-549 11.92 0.68 40.8 5.68 6.25 0.00 52% 48% 75 86 SCB-85 13-550 50.14 0.89 53.4 1.98 48.16 0.00 96% 4% 74 75 Total 475.20 184.87 284.12 6.21 61% 39% Grand Total 1841.17 696.03 971.14 174.01 62% 38% City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® Page 1 of 1 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 2.01-4.doc\050506 TABLE 2.01-4 FUTURE CONDITIONS HYDROLOGIC PARAMETER Basin ID Structure ID Drainage Basin Area (ac) Tc (hrs) Tc (min) Total Impervious Area (ac) Total Pervious Area (ac) Total Pervious Ag. (ac) Pervious (%) Impervious (%) Pervious RCN Composite RCN CCB-05 D-OF-3 46.68 0.47 28.2 21.15 25.51 0.00 55% 45% 74 85 CCB-10 Outfall 1 134.37 0.75 45.0 66.43 67.88 0.00 51% 49% 75 86 CCB-15 06-462 15.97 0.32 19.2 5.94 10.02 0.00 63% 37% 74 83 CCB-20 06-602 27.78 0.89 53.4 11.55 16.22 0.00 58% 42% 74 84 Total 224.80 105.07 119.63 0.00 53% 47% NBB-05 06-469 7.00 0.56 33.6 2.87 4.13 0.00 59% 41% 74 84 NBB-10 06-552 14.29 0.44 26.4 6.73 7.56 0.00 53% 47% 75 86 NBB-15 06-653 21.75 0.70 42.0 8.74 12.99 0.00 60% 40% 74 84 NBB-20 06-770 26.03 0.70 42.0 5.51 20.51 0.00 79% 21% 74 79 NBB-25 06-1062 7.08 0.39 23.4 3.60 3.48 0.00 49% 51% 74 86 NBB-30 06-688 29.72 0.34 20.4 17.25 12.46 0.00 42% 58% 76 88 NBB-35 06-843 3.98 0.30 18.0 3.03 0.95 0.00 24% 76% 75 92 NBB-40 06-846 6.08 0.09 5.4 5.01 1.06 0.00 18% 82% 74 94 NBB-45 06-847 4.25 0.08 4.8 4.03 0.22 0.00 5% 95% 74 97 NBB-50 06-1293.2 2.31 0.09 5.4 2.25 0.06 0.00 3% 97% 74 97 NBB-55 LP-5 18.43 0.30 18.0 6.91 11.51 0.00 62% 38% 76 84 Total 140.93 65.93 74.94 0.00 53% 47% SBB-05 06-471 16.63 0.31 18.6 7.03 9.60 0.00 58% 42% 74 84 SBB-10 06-474 20.38 0.62 37.2 7.18 13.19 0.00 65% 35% 74 83 SBB-15 06-473 73.71 0.77 46.2 28.70 44.99 0.00 61% 39% 73 81 SBB-20 AEW-1 19.10 0.54 32.4 7.60 11.49 0.00 60% 40% 74 84 SBB-25 13-420 71.15 0.71 42.6 36.87 34.25 0.00 48% 52% 75 87 SBB-30 13-457 21.87 0.19 11.4 12.62 9.24 0.00 42% 58% 74 88 SBB-35 13-460 4.34 0.33 19.8 2.40 1.94 0.00 45% 55% 75 88 SBB-40 AD-4 9.89 0.63 37.8 0.28 9.60 0.00 97% 3% 74 75 SBB-41 AP-1 16.30 0.36 21.6 4.49 11.81 0.00 72% 28% 74 81 SBB-42 AD-3 6.93 0.13 7.8 4.78 2.14 0.00 31% 69% 74 91 SBB-45 13-1217 24.46 0.18 10.8 21.26 3.18 0.00 13% 87% 74 95 SBB-50 13-1221 23.82 0.13 7.8 18.70 5.10 0.00 21% 79% 75 93 SBB-55 AEW-15 26.46 0.44 26.4 14.84 11.62 0.00 44% 56% 75 88 SBB-60 STR-10 665.20 1.05 63.0 337.84 321.52 5.66 49% 51% 81 88 Total 1000.25 504.59 489.68 5.66 49% 50% SCB-05 16-430 6.18 0.29 17.4 2.89 3.29 0.00 53% 47% 74 85 SCB-10 16-428 30.35 0.53 31.8 15.19 15.14 0.00 50% 50% 74 86 SCB-15 06-640 24.37 0.40 24.0 12.34 12.01 0.00 49% 51% 74 86 SCB-20 06-678 18.95 0.73 43.8 8.81 10.13 0.00 54% 46% 74 85 SCB-25 06-1355 13.72 0.11 6.6 7.53 6.19 0.00 45% 55% 78 89 SCB-30 16-647 20.26 0.83 49.8 11.48 8.73 0.05 43% 57% 75 88 SCB-35 06-773 51.20 0.79 47.4 36.31 14.86 0.00 29% 71% 75 91 SCB-40 40D-19 9.30 1.07 64.2 4.61 4.69 0.00 50% 50% 76 87 SCB-45 40D-17 2.04 0.14 8.4 0.74 1.29 0.00 64% 36% 80 86 SCB-50 WP-1 31.38 0.21 12.6 19.57 11.80 0.00 38% 62% 75 89 SCB-55 40D-12 20.20 0.30 18.0 10.16 10.02 0.00 50% 50% 77 87 SCB-60 13-2371 9.18 0.25 15.0 5.60 3.58 0.00 39% 61% 78 90 SCB-65 40D-7 7.97 0.67 40.2 4.84 3.12 0.00 39% 61% 75 89 SCB-70 13-792 34.92 0.66 39.6 22.28 12.62 0.00 36% 64% 74 89 SCB-75 13-764 133.14 0.71 42.6 40.77 92.32 0.00 69% 31% 74 81 SCB-80 13-549 11.92 0.68 40.8 5.67 6.25 0.00 52% 48% 75 86 SCB-85 13-550 50.14 0.89 53.4 1.98 48.14 0.00 96% 4% 74 75 Total 475.20 210.77 264.19 0.05 56% 44% Grand Total 1841.17 886.36 948.44 5.71 52% 48% City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® 2-5 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S2.doc\052506 2.03 FOX RIVER AND LAKE WINNEBAGO REGULATORY LEVELS 2.03 FOX RIVER AND LAKE WINNEBAGO REGULATORY LEVELS Return Frequency Elevation (ft) Summer Target Maximum 747.55 10-year 747.56 50-year 748.26 100-year 748.36 500-year 748.96 Table 2.03-1 Regulatory Still Water Levels–Lake Winnebago (National Geodetic Vertical Datum of 1929–NGVD 1929) Return Frequency Campbell Creek Elevation (ft) Sawyer Creek Elevation (ft) 10-year 748.65 748.80 50-year 749.20 .20 749.45 749.45 100-year100-year 749.55 749.55 749.65 749.65 500-year500-year 750.10 750.10 750.20 750.20 Table 2.03-2 Regulatory Levels–Fox River Confluence with Campbell Creek and Sawyer Creek (NGVD 1929) Table 2.03-2 Regulatory Levels–Fox River Confluence with Campbell Creek and Sawyer Creek (NGVD 1929) A Flood Insurance Study was completed for the Fox River and Lake Winnebago on June 6, 1995, by Carl Crane, Inc. (now Foth and Van Dyke). This study has been updated as the Flood Insurance Study, Winnebago County, Wisconsin, and Incorporated Areas, Federal Emergency Management Association (FEMA), March 17, 2003. The regulatory highwater elevations (still water level) for Lake Winnebago based on the updated study are shown in Table 2.03-1. Copies of the flood profiles for the Fox River and Sawyer Creek are included as Figure 2.03-1 and Figure 2.03-2. The regulatory elevations at the confluence of Campbell Creek/Fox River and Sawyer Creek/Fox River are shown in Table 2.03-2. A Flood Insurance Study was completed for the Fox River and Lake Winnebago on June 6, 1995, by Carl Crane, Inc. (now Foth and Van Dyke). This study has been updated as the Flood Insurance Study, Winnebago County, Wisconsin, and Incorporated Areas, Federal Emergency Management Association (FEMA), March 17, 2003. The regulatory highwater elevations (still water level) for Lake Winnebago based on the updated study are shown in Table 2.03-1. Copies of the flood profiles for the Fox River and Sawyer Creek are included as Figure 2.03-1 and Figure 2.03-2. The regulatory elevations at the confluence of Campbell Creek/Fox River and Sawyer Creek/Fox River are shown in Table 2.03-2. 2.04 GAUGING STATIONS ON FOX RIVER AND LAKE WINNEBAGO 2.04 GAUGING STATIONS ON FOX RIVER AND LAKE WINNEBAGO There is a rainfall gauging station (USGS 04082400) located on the Fox River and 400 feet downstream of the USH 45 and STH 26 bridge in Oshkosh. In addition, there is a stage gage (USGS 04082500) on Lake Winnebago located at 905 Bay Shore Drive, 800 feet east of the mouth of the upper Fox River. Both of these gages are operated in cooperation with United States Army Corps of Engineers (USACE) and information regarding them can be found at the following two Web sites. There is a rainfall gauging station (USGS 04082400) located on the Fox River and 400 feet downstream of the USH 45 and STH 26 bridge in Oshkosh. In addition, there is a stage gage (USGS 04082500) on Lake Winnebago located at 905 Bay Shore Drive, 800 feet east of the mouth of the upper Fox River. Both of these gages are operated in cooperation with United States Army Corps of Engineers (USACE) and information regarding them can be found at the following two Web sites. http://waterdata.usgs.gov/wi/nwis/uv/?site_no=04082400&PARAmeter_cd=00045http://waterdata.usgs.gov/wi/nwis/uv/?site_no=04082400&PARAmeter_cd=00045 http://waterdata.usgs.gov/wi/nwis/dv/?site_no=04082500&PARAmeter_cd=00065 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® 2-6 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S2.doc\052506 2.05 LAKE WINNEBAGO 2004-2005 REGULATION STRATEGY According to the following two USACE Web sites, the following information relative to the regulation of Lake Winnebago dated November 24, 2004, is presented. All elevations from this Web site were reported as being in City of Oshkosh datum. (http://www.lre.usace.army.mil/_kd/Items/actions.cfm?action=Show&item_id=4144&destination=ShowItem) (http://www.lre.usace.army.mil/_kd/Items/actions.cfm?action=Show&item_id=4207&destination=ShowItem) Table 2.05-1 lists Lake Winnebago regulatory elevations as documented by the USACE. This table uses a conversion factor of adding 744.55 to the gage height reading in feet to convert the gage reading to NGVD 1929 datum. This differs from the USACE conversion stated on the Web site but matches information received by the USACE via e-mail for a similar project in the City. Date Elevation (ft) Early Spring–Starting at Ice Break-up Fill To Elevation Range By May 1 2.4 to 2.7 (746.95 to 747.25) Early Summer–By June 1 2.7 to 3.0 (747.25 to 747.55) Mid Summer–by July 1 Minimum of 3.0 (747.55) Winter Drawdown 2.5 (747.05) from mid-Oct. to early Jan. 1.62 (745.77) by end February Notes: 1. Navigation season is considered Ice Breakup to Oct. 10. 2. Stage = FT above Oshkosh Datum (0 = 744.35 IGLD 85) according to USACE Web site. 3. Conversion from stage to NGVD29 = +744.55 per correspondence from City 4. Record Low = 0.33 = 744.88 (March 9). 5. Record High = 3.81 = 748.36 (July 10). Table 2.05-1 Lake Winnebago 2004-2006 Regulation Strategy 2.06 RAINFALL GAGES IN OSHKOSH The City of Oshkosh operates a tipping bucket rain gauge at the wastewater treatment plant (WWTP). We have obtained data regarding a June 11, 2004, rainfall event from the City to help in calibrating our model. The format of this rainfall data is in daily rainfall totals. The National Weather Service maintains a climatological data station at the Oshkosh Wittman Regional Airport. Hourly precipitation data was available for the June 11, 2004, storm event and the month preceding it. The USGS in cooperation with USACE has a precipitation gage on the Fox River in Oshkosh (USGS 04082400). We have obtained data regarding the June 10/11, 2004, rainfall event from the USACE. The total precipitation for June 10 and June 11, 2004 according to this gage was 3.97 inches of rainfall. For the period from 1 P.M. on June 10, 2004 to 12 P.M. on June 11, 2004 (the bulk of the June 10/11, 2004, rainfall event), this gage showed 3.92 inches of rainfall. We used the rainfall data from the USACE gage in our modeling of the June 10/11, 2004 storm. The rainfall totals from the Oshkosh WWTP gage and the National Weather Service gage at the Oshkosh Airport closely match the USACE data used in our model. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® Page 1 of 1 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Figure 2.03-1.doc\052506 FIGURE 2.03-1 FOX RIVER FLOOD PROFILES City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® Page 1 of 1 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Figure 2.03-2.doc\052506 FIGURE 2.03-2 SAWYER CREEK FLOOD PROFILES City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® 2-7 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S2.doc\052506 The June 10/11, 2004 storm event using USACE gage data is illustrated in Figure 2.06-1 and corresponds to about a 15-year, 18-hour storm event (cumulative 3.61 inches of rainfall) or about a 16-year, 24-hour event (cumulative 3.92 inches of rainfall) when comparing to Huff rainfall amounts and durations and starting the rainfall event at 1 P.M. on June 10, 2004. If the storm is considered to start at 7 P.M. on June 10 and continue through 9 A.M. on June 11, then the storm would be considered about a 20-year, 12-hour storm (cumulative 3.63 inches of rainfall) when comparing to Huff rainfall amounts and durations. 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 Ra i n f a l l ( I n c h e s ) 1: 0 0 P M 2: 0 0 P M 3: 0 0 P M 4: 0 0 P M 5: 0 0 P M 6: 0 0 P M 7: 0 0 P M 8: 0 0 P M 9: 0 0 P M 10 : 0 0 P M 11 : 0 0 P M 12 : 0 0 A M 1: 0 0 A M 2: 0 0 A M 3: 0 0 A M 4: 0 0 A M 5: 0 0 A M 6: 0 0 A M 7: 0 0 A M 8: 0 0 A M 9: 0 0 A M 10 : 0 0 A M 11 : 0 0 A M 12 : 0 0 P M Hours June 10 & 11, 2004 Storm Event USACE Gage in Oshkosh, WI Figure 2.06-1 June 10 and 11, 2004, Storm Event–USACE Gage in Oshkosh, Wisconsin 2.07 LOCATIONS OF EXISTING FLOODING PROBLEMS A. Apparent Contributions to Flooding Flooding in the City of Oshkosh occurs most commonly after short, intense thunderstorm events in the spring and summer months. In general, flooding appears to be because of one, or a combination, of several factors: 1. Lack of positive drainage: The flat surface topography in certain areas of the City discourages positive drainage of stormwater. In certain cases, the stormwater drainage is in a saw-tooth pattern whereby storm sewer handles smaller storm flows but numerous depressional areas are created to accomplish surface drainage. As a result, stormwater accumulates in the depressional areas with larger storm events, causing flooding of adjacent land. An example of this is along Reichow Street and Crystal Springs Avenue. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® 2-8 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S2.doc\052506 2. Insufficient storage capacity: The capacity of depressional areas at many locations is exceeded by the volume of stormwater runoff discharging to the depressional area. This causes water levels in the depressional area to back up onto adjacent streets or yards. Previous flooding at the intersection of E. Murdock Avenue and Harrison Street in the Anchorage Basin is an example of this condition. 3. Insufficient outlet capacity: Constructed drainage structures have insufficient capacities to convey the peak discharge from intense storm events. Backups upstream of the culvert beneath S. Washburn Street south of Dickinson Avenue may be an example of this condition. The culvert downstream of Landmark Plaza is also an example of insufficient outlet capacity. 4. Insufficient inlet capacity: Drainage from streets and other surface areas may be restricted by the limited capacity of street or low point inlets at several locations in the Campbell Creek watershed including at the Landmark Plaza. 5. High lake/river/creek levels: High lake and river levels reduce the outlet capacity of the trunk storm sewer line located upstream of the Campbell Creek discharge at the Fox River as well as at the two outfalls on Sawyer Creek. 6. Drainage Basin Cross Connections: Cross connections allow water from another stormwater drainage basin or subbasin to enter into an adjacent basin, which may overwhelm drainage facilities in the adjacent basin. The drainage basin cross connections under USH 41 in the Campbell Creek drainage basin appear to have been the natural/original route of stormwater conveyance. In this report, we refer to these as cross connections or diversions simply because stormwater can go two directions at these locations. 7. First Floor Elevation Built Too Low With Insufficient Overflow Route: This appears to be the case at Landmark Plaza. Historically, flooding has caused extensive property damage in the Campbell Creek watershed. In addition, nuisance flooding involving water accumulation in yards and streets is common. B. Flooding Locations Seven locations of recurrent flooding have been identified in the Campbell Creek watershed based on discussions with City staff and shown on the City of Oshkosh’s Stormwater Management Projects Map which identifies Drainage Problem Areas. In addition, Map 2 of the December 1994 stormwater plan identifies a number of residences in the watershed that reported flooding during a June 1993 storm event. These locations are identified in Figure 2.07-1 and described in Table 2.07-1 PROBLEM AREAS NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 2.07-11-382.021 City of Oshkosh Town of Algoma City of Oshkosh Town of Algoma Town of Nekimi Town of Nekimi City of Oshkosh Town of Algoma FOX RIVER CAMPBELL CREEK Town of Nekimi Town of AlgomaCity of Oshkosh Bank Full Within Banks Within Banks US Route 41 State Road 44 State Road 91 Universal St. Oakwood Rd. W 20th Ave. Maricopa Dr. Dickinson Ave. Cumberland Trl. S Washburn St. Crystal Springs Ave. Moreland St. Reichow St. W 9th Ave. Mason St. W 4th Ave. Witzel Ave. N Sawyer St. Josslyn St. N Westfield St. SAWYER CREEK 42" RCP IE = 775.25 3' x 4.5' R CP Box IE = 762.54 6/11/04 High Water Mark 748.43 (per city) 6/10/04 Fox River Gage ELEV. = 747.66 6/11/04 High Water Mark 762.75 6/11/04 High Water Mark 756.61 (per city) Diversion PT 1 High PT = 776.35 4 6 5 1 3 2 S:\@SAI\351--400\382\021\GIS\Report Figures\Problem Areas.mxd 0 1,500 3,000 750 Feet Legend Municipal Boundary Drainage Basin Boundary Landmark Plaza Sub Drainage Basin Boundary Storm Manhole Storm Sewer June 11, 2004 Flooding June 1993 Reported Flooding Navigable Stream 100-year Floodplain Wetlands Drainage Problem Areas 2 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 2–Contributing Watershed Characteristics Prepared by Strand Associates, Inc.® 2-9 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S2.doc\052506 ID Location Apparent Causes (See Legend) Type of Damage 1 Landmark Plaza a, b, c, d, e, f, g 1,2, 4 2 Universal Street near STH 44 b, c 1, 4 3 S. Washburn Street near Dickinson Avenue b, c 1, 4 4 Reichow Street and Crystal Springs Avenue Area a, c, d 1, 2, 4 5 School yard northwest of Mason St./W. 9th Ave. a,b,c,d 1,2,4 6 Street flooding upstream of Campbell Creek discharge a, b, c, d, e 1, 2, 4 7 Various Residences a, c, d 1, 2, 4 Legend: Apparent Contribution to Flooding: Type of Damage: a. Lack of positive drainage route. 1. Street/Yard/Field Flooding b. Insufficient storage capacity. 2. Property/Structural Damage c. Insufficient outlet capacity. 3. Erosion d. Insufficient inlet capacity. 4. Safety Issue e. High lake, river, creek levels f. Drainage basin cross connections g. First Floor Elevation Built Too Low With Insufficient Overflow Route Table 2.07-1 Locations of Existing Flooding SECTION 3 ENGINEERING ANALYSIS City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® 3-1 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S3.doc\052506 3.01 HYDROLOGIC ANALYSIS A. Purpose of Evaluation A watershed model was developed for the Campbell Creek drainage area. This model estimated peak discharges and stormwater runoff volumes from individual drainage subbasins. This data was used to size stormwater detention and conveyance facilities and estimate potential flood depths at critical watershed locations. Stormwater modeling was completed for the following scenarios: 1. Existing conditions peak discharge and stormwater runoff volumes. This analysis estimated where the existing capacities of storm sewer facilities were exceeded and included incorporation of the existing Wal-Mart, golf course, and Armory detention basins into the models. 2. June 10/11, 2004, storm event peak discharges and stormwater runoff volumes. This analysis was run to determine stormwater characteristics that occurred with this storm. 3. Future conditions peak discharges and stormwater runoff volumes. Estimating peak discharges and runoff volumes to areas of known flooding allowed potential drainage projects to be developed and properly sized to accommodate future peak discharges. Certain models incorporated the detention basin that was recommended at the Armory/Menard’s site in the December 1994 Stormwater Plan as discussed in Section 4. B. Methodology For this project, hydrologic models were developed using the RUNOFF module of the computer model XP-SWMM TM. XP-SWMMTM is a proprietary model based on the USEPA-developed Stormwater Management Model (SWMM TM ). XP-SWMMTM estimates peak stormwater discharges and volumes based on mathematical input parameters representing precipitation depth and time distribution, drainage area, land use, and time of concentration for each subbasin. Primary input parameters include the drainage area, runoff curve number (RCN), and time of concentration (Tc). The RCN considers land use and percentage of impervious area, soil type, and saturation conditions to impact the volume of stormwater runoff generated for a given rainfall depth. The Tc is the time it takes for stormwater to travel from the most hydrologically remote point in the watershed to the subbasin outlet. Parameters representing rainfall depth and distribution and watershed storage are also included in the model. Based on user input coding, XP-SWMMTM generates hydrographs for each subbasin, routes them through storage areas, and combines them at appropriate locations. The result is a rainfall-runoff model of the storm event of interest. For this project, hydrographs were generated for the 1-, 2-, 5-, 10-, 25-, 50- and 100-year storms under existing land use conditions. The Huff rainfall (1st Quartile for storms of duration 6 hours and less and 2nd Quartile for storms of duration of 6.1 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® 3-2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S3.doc\052506 to 12-hour) distribution was analyzed for this project. A sensitivity analysis was performed to identify the storm duration resulting in the highest probable peak discharges at various watershed locations (typically referred to as the “critical duration”). Our analysis concluded that the critical storm duration creating the greatest peak disc harges watershed-wide under existing land use conditions is a 2-hour storm. It was further concluded that the critical duration is a 12-hour storm at Landmark Plaza in terms of creating the highest flooding volumes because of the long retention times/flooding upstream of Landmark Plaza under existing land use conditions. We have thus analyzed each of our alternatives for the 10-year and 100-year storm events of both 2-hour and 12-hour duration under future land use conditions. C. Modeling Results Table 3.01-1 includes summaries of peak discharges calculated by XP-SWMMTM for each subbasin in the Campbell Creek watershed for existing land use conditions for a 2-hour duration storm. Peak discharges for the June 10/11, 2004 storm are arrived at by using RCNs that are 20 percent higher than existing land use conditions to account for the substantial rainfall in the month preceding the June 10/11, 2004, storm event. The 20 percent increase in pervious area curve numbers increases the composite pervious area curve number from 74 (Antecedent Moisture Condition II) up to 91. This closely approximates Antecedent Moisture Condition III. Table 3.01-2 includes summaries of peak discharges calculated by XP-SWMMTM for each subbasin in the Campbell Creek watershed for future land use conditions for a 2-hour duration storm. As discussed in Section 2, all new development over 1 acre within the watershed will need to provide detention that will assist in providing peak flow reduction in the watershed under future conditions. Our models do not include this future detention. 3.02 HYDRAULIC ANALYSIS A. Methodology The Extended Transport (EXTRAN) module of the XP-SWMMTM computer model was used to calculate the hydraulic capacity of the existing storm sewer system under existing conditions. Figure 3.02-1, attached at the back of this report, shows a schematic of the storm sewer network as modeled. EXTRAN is a dynamic flow routing model that routes inflow hydrographs through an open channel and/or closed conduit system, computing the time history of flows and heads throughout the system. Input to EXTRAN includes the following: 1. The physical geometry of the storm sewer system, including culvert sizes and shapes, ground and invert elevations, and culvert connectivity information. For this project, physical information regarding the culvert system was obtained from the City of Oshkosh’s storm sewer GIS layer along with field survey information. 2. Data regarding special hydraulic structures in the system including weirs, check valves, and storage junctions. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 1 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.01-1.doc\050506 TABLE 3.01-1 PEAK DISCHARGE RATES BY SUBBASIN (2 HOUR DURATION)–EXISTING CONDITIONS Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow** (cfs) Basin ID Node 1-yr 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 6/11/2004 CCB-05 D-OF-3 9 14 24 33 51 69 92 27 CCB-10 Outfall 1 26 41 65 90 134 180 236 78 CCB-15 06-462 3 4 7 11 17 23 32 9 CCB-20 06-602 4 6 11 15 23 31 41 16 NBB-05 06-469 1 2 3 4 7 9 12 4 NBB-10 06-552 3 5 8 11 17 23 30 8 NBB-15 06-653 3 5 9 12 19 26 35 12 NBB-20 06-770 2 4 7 11 17 25 34 14 NBB-25 06-1062 2 3 4 6 9 12 16 4 NBB-30 06-688 9 14 22 30 44 58 75 18 NBB-35 06-843 2 3 4 6 8 10 13 2 NBB-40 06-846 4 6 9 12 17 23 29 4 NBB-45 06-847 5 7 10 12 16 20 24 3 NBB-50 06-1293.2 3 4 5 7 9 11 13 1 NBB-55 LP-5 4 6 10 14 22 30 40 11 SBB-05 06-471 3 5 9 12 19 26 35 10 SBB-10 06-474 3 5 8 11 17 24 32 12 SBB-15 06-473 4 9 17 26 43 62 86 37 SBB-20 AEW-1 3 5 8 12 18 25 34 11 SBB-25 13-420 15 24 38 51 76 101 132 41 SBB-30 13-457 7 11 17 24 35 45 60 13 SBB-35 13-460 1 2 3 4 6 8 11 3 SBB-40 AD-4 0 1 2 3 5 8 11 5 SBB-41 AP-1 2 3 6 9 14 20 28 9 SBB-42 AD-3 1 2 4 5 8 11 15 4 SBB-45 13-1217 16 22 31 40 57 74 95 15 SBB-50 13-1221 15 21 31 41 60 79 101 14 SBB-55 AEW-15 7 11 18 24 35 47 61 16 SBB-60 STR-10 80 133 221 313 483 658 878 386 SCB-05 16-430 1 2 4 5 8 11 14 4 SCB-10 16-428 6 10 16 23 34 46 60 18 SCB-15 06-640 6 9 14 20 30 40 53 14 SCB-20 06-678 3 5 8 12 18 24 32 11 SCB-25 06-1355 6 8 12 16 24 34 46 8 SCB-30 16-647 3 5 8 11 17 23 31 12 SCB-35 06-773 10 16 25 35 52 69 90 30 SCB-40 40D-19 2 3 4 6 8 11 14 5 SCB-45 40D-17 1 1 1 2 3 4 5 1 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 2 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.01-1.doc\050506 Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow** (cfs) Basin ID Node 1-yr 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 6/11/2004 SCB-50 WM P-1 12 18 27 36 52 69 89 19 SCB-55 40D-12 6 9 14 20 29 38 50 12 SCB-60 13-2371 4 6 8 11 16 20 26 6 SCB-65 40D-7 1 2 3 5 7 10 14 5 SCB-70 13-792 5 9 14 20 31 43 57 20 SCB-75 13-764 14 25 44 65 103 142 193 74 SCB-80 13-549 2 4 6 8 12 16 22 7 SCB-85 13-550 2 4 8 13 23 34 48 26 **Max. Flow for 6/11/04 storm arrived at by increasing RCNs by 20% to account for higher antecedent moisture condition due to previous month’s rainfall. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 1 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.01-2.doc\050506 TABLE 3.01-2 PEAK DISCHARGE RATES BY SUBBASIN (2 HOUR DURATION)–FUTURE CONDITIONS Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Basin ID Node 1-yr 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr CCB-05 D-DF-3 9 14 24 33 51 69 92 CCB-10 Outfall 1 26 41 65 90 134 180 236 CCB-15 06-462 3 4 7 11 17 23 32 CCB-20 06-602 4 6 11 15 23 31 41 NBB-05 06-469 1 2 3 4 7 9 12 NBB-10 06-552 3 5 8 11 17 23 30 NBB-15 06-653 3 5 9 12 19 26 35 NBB-20 06-770 2 4 7 11 17 25 34 NBB-25 06-1062 2 3 4 6 9 12 16 NBB-30 06-688 10 15 23 31 45 59 76 NBB-35 06-843 2 3 4 5 8 10 13 NBB-40 06-846 4 6 9 12 17 23 29 NBB-45 06-847 5 7 10 12 16 20 24 NBB-50 06-1293.2 3 4 5 7 9 11 13 NBB-55 LP-5 4 6 10 14 22 30 40 SBB-05 06-471 3 5 9 12 19 26 35 SBB-10 06-474 3 5 8 11 17 24 32 SBB-15 06-473 9 16 27 38 59 82 109 SBB-20 AEW-1 3 5 8 12 18 25 34 SBB-25 13-420 15 24 38 51 76 101 132 SBB-30 13-457 7 11 17 24 35 45 60 SBB-35 13-460 1 2 3 4 6 8 11 SBB-40 AD-4 0 1 2 3 5 8 11 SBB-41 AP-1 2 3 6 9 15 21 28 SBB-42 AD-3 3 5 7 9 14 19 25 SBB-45 13-1217 18 25 35 46 64 81 102 SBB-50 13-1221 15 21 31 41 60 79 101 SBB-55 AEW-15 7 11 18 24 35 47 61 SBB-60 STR-10 166 243 364 482 689 895 1144 SCB-05 16-430 1 2 4 5 8 11 14 SCB-10 16-428 6 10 16 23 34 46 60 SCB-15 06-640 6 9 14 20 30 40 53 SCB-20 06-678 3 5 8 12 18 24 32 SCB-25 06-1355 6 8 12 16 24 34 46 SCB-30 16-647 5 7 11 15 22 28 37 SCB-35 06-773 17 25 37 48 67 86 109 SCB-40 40D-19 2 3 4 6 8 11 14 SCB-45 40D-17 1 1 1 2 3 4 5 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 2 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.01-2.doc\050506 Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Max Flow (cfs) Basin ID Node 1-yr 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCB-50 WM P-1 12 18 27 36 52 69 89 SCB-55 40D-12 6 9 14 20 29 38 50 SCB-60 13-2371 4 6 8 11 16 20 26 SCB-65 40D-7 2 3 5 7 10 13 17 SCB-70 13-792 10 15 23 31 44 58 74 SCB-75 13-764 14 25 44 65 103 142 193 SCB-80 13-549 2 4 6 8 12 16 22 SCB-85 13-550 2 4 8 13 23 34 48 *** As a note, subbasin SBB-60 has been broken into two smaller basins in the future conditions models with 462.55 acres entering at a new node named RR D in the model and 202.65 acres entering at the node named STR-10. Further breakdown of basin SBB-60, SCB-85, SCB-75, SCB-70, SCB-80, and NBB-55 to accommodate the alternatives analysis has been incorporated into the models for certain alternatives where needed. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® 3-3 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S3.doc\052506 3. Roughness coefficients for existing and proposed conduits. 4. Inflow hydrographs at critical nodes in the system. For this project, hydrographs were computed using the XP-SWMMTM RUNOFF module, as described in Section 3.01B. 5. Boundary conditions defining starting water surface elevations and other inlet and outlet conditions. For this project, the summer target maximum for Lake Winnebago is considered 747.55 NGVD 1929 datum. Return Frequency Elevation (ft) 6/11/04 WSEL 750.49 1-year 747.55 2-year 747.55 5-year 748.78 10-year 749.57 25-year 750.49 50-year 751.04 100-year 751.04 Table 3.02-1 Boundary Conditions at Sawyer Creek/Westfield Outfall (NGVD 1929) Return Frequency Elevation (ft) 6/11/04 WSEL 754.33 1-year 747.55 2-year 747.55 5-year 751.06 10-year 752.55 25-year 754.33 50-year 755.37 100-year 755.37 Table 3.02-2 Boundary Conditions at Sawyer Creek/Washburn Street Outfall (NGVD 1929) Critical components of this modeling effort are the “boundary conditions” used at the pipe discharge at Campbell Creek and the two pipe discharges at Sawyer Creek. “Boundary conditions” means the assumed elevation of the water surface at the discharge point of the storm sewer being modeled. The boundary conditions at the Campbell Creek outfall being used are the Lake Winnebago pool elevations reported on the USACE gage. The gage elevation or summer target maximum is always used in our model as the boundary condition at the Campbell Creek outfall because of its proximity to the gage. The Lake Winnebago pool elevation backwater effects (still water elevation) appear to extend up to the Sawyer Creek/Washburn Street outfall and possibly beyond as a relatively flat surface, so the summer target maximum elevations for the lake can be used as boundary conditions for the smaller storms in Sawyer Creek. The boundary conditions at Sawyer Creek/Westfield Drive outfall and Sawyer Creek/Washburn Street outfall are elevations arrived at by running the FIS HEC-2 model for Sawyer Creek starting with an elevation of 747.55 (summer target maximum) at the Fox River/Sawyer Creek confluence (see Tables 3.02-1 and 3.02-2). 6. Stage-storage-outflow data for impoundments in the watershed, including the golf course detention, Wal-Mart detention, and Armory detention. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® 3-4 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S3.doc\052506 7. Pump curve data for the analyzed stormwater pumping station. Output information from the EXTRAN model includes the following: 1. Time histories of flows and depths through individual storm sewer facility reaches for various storm events. 2. Estimates of cumulative stormwater volumes overflowing the system at various locations for extreme storm events. B. Model Calibration Calibration of the model to reproduce the elevations and flooding volumes that were reported during the June 10/11, 2004, storm event was performed to compare modeled results with observed conditions. We calibrated the model to the elevation surveyed as the high water mark at Landmark Plaza (762.75). Using survey obtained on January 19, 2006, stage versus storage relationships were developed for the Landmark Plaza lands and the Tippler Junior High lands. This survey data is shown in Figure 3.02-2. Each of these two basins (designated Landmark Basin and Tippler Basin) were modeled as detention pond basins with overflow routes that represent what happens in these areas during large storm events. The model shows that during the June 10/11, 2004 storm event, the Landmark Plaza lands (including portions of Westfield Drive and surrounding residences) flood up to a peak elevation of 762.72, which equates to a peak storage volume of 16.56 acre-feet. This is also similar in elevation to the surveyed elevation (762.89) along Westfield Drive (in the cul-de-sac) that was indicated as a high water mark by a resident on Westfield Drive. The Tippler Junior High depressional area is modeled to pond to an elevation of 760.30 with peak storage volume of 11.07 acre-feet. Modifications made to the model to arrive at this calibration include the following. 1. Change of Manning’s “n” value from 0.026 to 0.028 in the storm sewers downstream of Landmark Plaza (from node P-06-841 to P-06-408.2) to account for likely increased roughness in this section of pipe because of age. According to City storm sewer system maps, this stretch of storm sewer was built between 1958 and 1970, with older sections being on the downstream end of this stretch. 2. Increase of pervious area curve numbers by 20 percent to account for the substantial rainfall in the month preceding the June 10/11, 2004, storm event. The 20 percent increase in pervious area curve numbers increases the composite pervious area curve number from 74 (Antecedent Moisture Conduction II) up to 91. This closely approximates Antecedent Moisture Condition III. 3. Use of a starting water surface elevation at the Campbell Creek outfall recorded by the USACE gage on the Fox River (747.66) on June 10, 2004. Use of a starting water surface elevation of 750.49 at the Sawyer Creek/Westfield outfall and 754.33 at the Sawyer Creek/Washburn outfall, which are the 5-year stormwater surface elevations at EXISTING SURVEY DATA AT LANDMARK PLAZA AND TIPPLER NORTH BRANCH CAMPBELL CREE K STORMWATER STUD Y CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 3.02-21-382.021 761 761 761 761 762 762 763 764765 762763 761 761 762 763 764 762 762 763 762 760 760 760760 761 761 761 761 762 762 762 762 760761762 763763 763 764 764 762 763 759 759 762 763 764 765766 760 760 761 758 758 761 762 759 759 762 763 760 760 761 760 760 760760 761 761 761 759 759 760 760 761 Overflow Elevation= 758.70 Overflow Elevation= 760.00 Overflow Elevation= 761.87 FFE=766.12 FFE=764.44 FFE=764.35 FFE=764.13 FFE=762.39 FFE=763.74 FFE=762.69 FFE=762.91 FFE=764.64 FFE=763.51 FFE=763.61 FFE=763.84 FFE=763.34 FFE=763.48 FFE=763.66 FFE=763.27 FFE=764.49 FFE=762.28 FFE=763.99 FFE=763.87 FFE=764.39 FFE=763.95 FFE=762.53 FFE=764.26 FFE=762.35 FFE=761.31 Node 06-1293.2 Node 06-847 Node 06-846 WITZEL AVE S EAGLE ST N KOELLER ST BISMARCK AVE US HWY 41 SOUTHBOUND US HWY 41 NORTHBOUND S WESTFIELD ST S WASHBURN ST W 4TH AVE W 2ND AVE W 3RD AVE N EAGLE ST N MEADOW ST LILAC ST N WESTFIELD ST MONTICELLO DR pvt S:\@SAI\351--400\382\021\GIS\Report Figures\Existing Survey Data.mxd 0 200 400100 Feet Legend Existing Contour Survey Shot Storm Sewer City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® 3-5 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S3.doc\052506 these locations, arrived at from modeling Sawyer Creek in HEC-RAS using a starting water surface elevation of 747.66 at the Fox River. 4. Based on these results, we believe the model provides a reasonable representation of flooding that occurred at Landmark Plaza on June 10/11, 2004. C. Design-Storm Evaluation Modeling of existing conditions shows that there are numerous areas with undersized stormwater conveyance facilities that frequently exceed their capacities and flood adjacent lands and streets. Table 3.02-3 lists the design capacity and physical characteristics of modeled links in the stormwater conveyance system. Table 3.02-4 includes summaries of peak discharges (2-hour duration) in each pipe reach including flows above the pipe in the street and ponding, if any, as well as the capacity in terms of design storm for each pipe reach under existing land use conditions. The yellow shading in Figure 3.02-4 shows the capacity of each storm reach. The gray shading shows storm reaches with less than a 1-year design storm capacity. Figure 3.02-1 is a graphic representation of the pipe reach design storm capacity under existing land use conditions. Modeling provided the following observations: 1. In certain areas, the existing storm sewer system has less than a recommended 10-year design storm capacity under existing conditions. In general, it appears that the North Branch, South Branch, Main Branch, and Sawyer Creek Branches range in capacity from 1-year up to 100-year capacity as shown in Figure 3.02-1. In areas where ponding is occurring because the pipe capacity is exceeded, the model is set up to detain these flows and allow them to enter back into the system once the pipe can accept the flow. This mimics street flooding that appears to occur in this system. However, it can also show that areas downstream of this ponding have higher capacities in terms of design storm than they would if subjected to the full upstream flows. Section 4 discusses the addition of dedicated detention in the system intended to replace this flooding volume or reduce the frequency of this street flooding. 2. Modeling results indicate that the existing 36-inch x 58-inch CMP downstream from Landmark Plaza has limited conveyance capacity because of the high Manning’s “n” values, minimal or reverse slope, and shallow cover. The average slope is approximately 0.23 percent. This limited downstream capacity creates a “bottleneck” causing flows to surcharge and inundate upstream areas including Landmark Plaza and appears to be a major factor in the flooding occurring at the Landmark Plaza. Any measures to increase flow rates from Landmark Plaza must also include either improved downstream conveyance or detention to maintain the system capacity. The challenge to upsizing this portion of the storm sewer will be dealing with cover issues and utility conflicts. 3. It appears that the low elevation at which Landmark Plaza was built is a major contributing factor to the flooding problems that are presently occurring. This is City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® 3-6 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S3.doc\052506 evidenced by the fact that the first floor elevation of the eastern Landmark Plaza building (762.28) is only approximately 0.41 feet above the lowest overflow elevation of 761.87 (located on the east side of Westfield Drive) that would allow stormwater from the Landmark Basin to discharge into the Tippler Basin. During the June 10/11, 2004 storm event, modeling results show that the overflow of the Landmark Basin would have had a 0.85-foot depth of stormwater flowing through it. As can be seen, approximately 0.44 feet of flooding of the eastern Landmark Plaza building occurred. According to our survey, the lowest first floor elevation of the homes along Westfield Drive in the area that appears to flood is 762.39 (221 S. Westfield Drive), which is about 0.11 feet higher than the first floor elevation of the eastern Landmark Plaza building. For comparison, the first floor elevation of the Tippler Junior High Administration Building (761.31) is 2.61 feet above the lowest overflow elevation (758.70) that would allow water from the Tippler Basin to discharge to the City road network east of the Tippler property. During the June 10/11, 2004 storm event, our model shows that the overflow of the Tippler Basin had a 1.60-foot depth of stormwater flowing through it. With the 1.60-foot depth of flow through the spillway, the Tippler Junior High Administration Building still had approximately 1.01 feet of freeboard between the modeled high water elevation and the first floor of the building. As described in more detail in Section 4.01, we would recommend a minimum of 1.5 feet of freeboard (with 2 feet being desirable) from the first floor elevation of a building to the computed 100-year water surface elevation adjacent to the building. This is consistent with NR 116-Wisconsin’s Floodplain Management Program. 4. According to the XP-SWMMTM model, Sawyer Creek did not directly back up into the Landmark Plaza during the June 10/11, 2004, rainfall event. However, it may have contributed to a reduced capacity in the upstream stormwater conveyance system. The elevations surveyed by the City on June 11, 2004, as high water marks and the relevant invert elevations of the storm sewer system at diversion locations are shown in Figure 2.07-1. 5. There are three diversion/cross connection points along Washburn Street that allow flows to move into and out of adjacent basins as shown in Figure 3.02-3. These three diversion/cross connection points appear to have been naturally occurring drainage routes prior to development occurring in these locations. This analysis indicates that the capacity of the culvert beneath USH 41 south of Dickinson Avenue is less than the peak discharge coming to that point (Diversion Point 1). This causes flows exceeding the capacity of the culvert to divert to the north toward the Landmark Plaza (Diversion Point 2). However, before the flows get to that point, they are attenuated by surface ponding between Diversion Point 1 and W. 9th Avenue; therefore the flows at Diversion Point 2 are not as high as at Diversion Point 1. Diverting additional flows toward Sawyer City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 1 of 5 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.02-3.doc\052506 TABLE 3.02-3 STORM SYSTEM CHARACTERISTICS Name Diameter (ft) Shape Roughness Conduit Slope (%) Length (ft) D-40D-1 3.10 Natural 0.100 0.40 276 D-40D-1.1 3.10 Natural 0.100 0.37 237 D-40D-10 7.77 Natural 0.100 0.27 172 D-40D-11 6.39 Natural 0.100 0.67 196 D-40D-12 5.29 Natural 0.100 0.14 181 D-40D-13 4.51 Natural 0.100 0.30 187 D-40D-14 4.51 Natural 0.100 0.50 196 D-40D-15 4.84 Natural 0.100 0.37 193 D-40D-16 4.84 Natural 0.100 0.18 131 D-40D-16.1 4.90 Natural 0.100 0.18 71 D-40D-17 4.90 Natural 0.100 0.48 46 D-40D-17.1 4.90 Natural 0.100 0.48 141 D-40D-18 5.06 Natural 0.100 0.38 176 D-40D-19 5.75 Natural 0.100 0.25 154 D-40D-2 3.36 Natural 0.100 0.77 191 D-40D-20 5.77 Natural 0.100 0.27 187 D-40D-21 6.12 Natural 0.100 1.02 76 D-40D-23 8.24 Natural 0.100 0.42 185 D-40D-3 3.31 Natural 0.100 0.19 186 D-40D-4 3.31 Natural 0.100 0.51 188 D-40D-5 3.45 Natural 0.100 0.33 173 D-40D-6 3.45 Natural 0.100 0.33 203 D-40D-7 4.95 Natural 0.100 0.24 177 D-40D-8 4.95 Natural 0.100 0.74 166 D-40D-9 7.77 Natural 0.100 0.35 195 D-AD-1 7.56 Natural 0.075 1.12 209 D-AD-2 9.90 Natural 0.075 0.16 167 D-AD-3 5.00 Natural 0.075 0.17 237 D-AD-4 5.03 Natural 0.075 0.35 169 D-AD-5 5.12 Natural 0.075 0.46 200 D-AEW-11 3.08 Natural 0.100 0.11 185 D-AEW-12 7.85 Natural 0.100 0.10 186 D-AEW-2 5.45 Natural 0.050 0.29 191 D-AEW-5 2.78 Natural 0.100 0.81 206 D-AEW-7 4.79 Natural 0.100 0.16 201 D-AEW-9 8.51 Natural 0.100 0.35 152 D-DITCH 3.66 Natural 0.050 0.51 187 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 2 of 5 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.02-3.doc\052506 Name Diameter (ft) Shape Roughness Conduit Slope (%) Length (ft) D-D-OF-1 5.25 Natural 0.035 0.16 199 D-D-OF-2 5.25 Natural 0.035 0.15 190 D-D-OF-3 5.01 Natural 0.035 -1.16 133 D-LP-2 2.71 Natural 0.035 0.40 184 D-LP-3 3.47 Natural 0.035 0.38 245 D-LP-4 3.78 Natural 0.100 -0.14 207 D-LP-5 3.78 Natural 0.035 0.86 174 D-LP-6 2.50 Circular 0.015 3.66 16 O-AEW-13 1.00 Trapezoidal 0.100 0.91 278 P-06-1062 4.83 Special 0.028 -1.10 26 P-06-1282 5.42 Special 0.015 0.25 24 P-06-1293 2.50 Circular 0.015 0.23 220 P06-1293.1 1.00 Circular 0.015 0.93 106 P-06-1293.2 1.00 Circular 0.015 0.13 180 P-06-1353 2.50 Circular 0.015 1.00 81 P-06-1354 1.50 Circular 0.015 1.05 10 P-06-1355 1.92 Special 0.015 1.00 49 P-06-1356 2.50 Special 0.015 1.00 10 P-06-1357 2.25 Circular 0.015 0.79 300 P-06-1370 5.00 Circular 0.015 0.41 174 P-06-1371 5.00 Circular 0.015 0.41 82 P-06-1387 1.00 Circular 0.015 1.48 51 P-06-1388 1.00 Circular 0.015 0.47 79 P-06-1389 1.00 Circular 0.015 1.05 23 P-06-1391 3.75 Special 0.015 0.59 51 P-06-1392 3.75 Special 0.015 1.38 27 P-06-408.1 4.83 Special 0.026 0.34 161 P-06-408.2 4.83 Special 0.026 0.34 160 P-06-462.1 4.83 Special 0.026 0.41 348 P-06-462.2 4.83 Special 0.026 0.41 349 P-06-467.1 4.83 Special 0.026 0.22 63 P-06-467.2 4.83 Special 0.026 1.22 63 P-06-469.1 4.83 Special 0.028 0.36 141 P-06-470.1 4.83 Special 0.026 0.24 197 P-06-470.2 4.83 Special 0.026 0.24 197 P-06-471.1 4.83 Special 0.026 0.15 356 P-06-471.2 4.83 Special 0.026 0.15 355 P-06-472.1 4.83 Special 0.026 -0.56 36 P-06-473.1 4.83 Special 0.016 0.17 112 P-06-473.2 4.83 Circular 0.016 0.20 111 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 3 of 5 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.02-3.doc\052506 Name Diameter (ft) Shape Roughness Conduit Slope (%) Length (ft) P-06-474.1 4.83 Special 0.016 0.25 404 P-06-474.2 4.83 Special 0.016 0.28 404 P-06-486.1 4.83 Special 0.028 0.15 338 P-06-487.1 4.83 Special 0.028 0.24 144 P-06-489.1 6.00 Special 0.026 0.43 257 P-06-489.2 6.00 Special 0.026 0.39 239 P-06-490 4.83 Special 0.026 0.39 339 P-06-492.1 4.83 Special 0.026 -0.11 18 P-06-493.1 4.83 Special 0.026 -0.02 561 P-06-494.1 4.83 Special 0.026 0.37 168 P-06-552.1 4.83 Special 0.028 0.32 296 P-06-553.1 4.83 Special 0.028 0.28 246 P-06-602.1 4.83 Special 0.026 -0.05 518 P-06-602.2 4.83 Special 0.026 -0.05 518 P-06-640.1 4.83 Special 0.026 0.02 102 P-06-653.1 4.83 Special 0.028 0.10 283 P-06-677.1 3.50 Circular 0.015 0.23 327 P-06-678 2.50 Circular 0.015 0.51 425 P-06-679 2.50 Circular 0.015 0.52 364 P-06-680 2.25 Circular 0.015 0.82 241 P-06-684 4.83 Special 0.028 0.10 170 P-06-685.1 4.83 Special 0.028 0.21 307 P-06-686 4.83 Special 0.028 0.05 165 P-06-687 4.83 Special 0.028 8.21 12 P-06-687.1 4.83 Special 0.028 -0.04 161 P-06-688.1 4.25 Special 0.026 0.04 302 P-06-770 4.83 Special 0.028 0.12 346 P-06-773.1 5.00 Circular 0.015 0.33 1092 P-06-836.1 4.83 Special 0.026 -0.47 47 P-06-837.1 4.83 Special 0.026 0.64 286 P-06-837.2 4.83 Special 0.026 0.64 286 P-06-841 4.83 Special 0.028 0.46 37 P-06-841.1 4.83 Special 0.028 0.16 189 P-06-842 3.00 Circular 0.015 0.20 80 P-06-843 2.00 Circular 0.015 0.36 253 P-06-844 2.00 Circular 0.015 0.20 213 P-06-845 2.00 Circular 0.015 0.38 21 P-06-846 2.00 Circular 0.015 0.23 156 P-06-847 1.50 Circular 0.015 0.54 267 P-06-848 1.50 Circular 0.014 0.60 180 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 4 of 5 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.02-3.doc\052506 Name Diameter (ft) Shape Roughness Conduit Slope (%) Length (ft) P-13-1216. 3.50 Circular 0.015 0.52 242 P-13-1217 4.00 Circular 0.015 0.22 133 P-13-1218 4.00 Circular 0.015 0.47 96 P-13-1219 4.00 Circular 0.015 0.39 139 P-13-1220 3.50 Circular 0.015 0.49 273 P-13-1221. 3.50 Circular 0.015 0.52 250 P13-1703.1 2.08 Special 0.026 0.02 96 P13-1703.2 2.08 Special 0.026 0.02 86 P13-1704.1 2.08 Special 0.026 0.35 31 P13-1704.2 2.08 Special 0.026 0.35 31 P-13-2371 4.50 Circular 0.015 0.14 173 P-13-2381 4.42 Special 0.015 0.38 84 P-13-2382 4.42 Special 0.015 1.27 21 P-13-2411. 3.17 Special 0.015 0.55 43 P-13-420 4.83 Special 0.026 0.00 147 P-13-452 5.42 Special 0.026 1.02 84 P-13-456.1 4.83 Special 0.026 0.47 322 P-13-457.1 4.00 Circular 0.015 0.32 240 P-13-458.1 4.00 Circular 0.015 0.41 85 P-13-459.1 4.00 Circular 0.015 0.42 384 P-13-460.1 4.00 Circular 0.015 0.43 350 P-13-471 6.33 Special 0.015 0.20 65 P-13-546.1 2.08 Special 0.026 0.63 65 P-13-546.2 2.08 Special 0.026 0.63 65 P-13-547.1 2.08 Special 0.026 0.02 313 P-13-547.2 2.08 Special 0.026 0.02 313 P-13-548.1 2.08 Special 0.026 0.14 91 P-13-548.2 2.08 Special 0.026 0.14 90 P-13-549.1 2.08 Special 0.026 0.14 156 P-13-549.2 2.08 Special 0.026 0.14 155 P-13-550.1 2.08 Special 0.026 0.03 511 P-13-550.2 2.08 Special 0.026 0.11 512 P-13-551.1 1.00 Circular 0.026 0.23 146 P-13-551.2 1.00 Circular 0.026 0.76 121 P-13-660 4.00 Circular 0.015 0.78 225 P-13-764 3.50 Circular 0.015 0.07 505 P-13-765.1 3.50 Circular 0.026 0.09 264 P-13-766.1 3.50 Circular 0.015 0.10 155 P-13-791.1 3.50 Circular 0.015 0.09 295 P-13-792.1 3.50 Circular 0.015 -0.04 200 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 5 of 5 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.02-3.doc\052506 Name Diameter (ft) Shape Roughness Conduit Slope (%) Length (ft) P-13-793.1 3.50 Circular 0.015 0.00 262 P-13-794 3.50 Circular 0.015 0.13 185 P-16-425.1 4.83 Special 0.026 0.27 254 P-16-426.1 4.83 Special 0.026 0.19 400 P-16-427.1 4.83 Special 0.026 0.17 401 P-16-428.1 5.42 Special 0.026 0.18 269 P-16-429.1 5.42 Special 0.026 0.18 402 P-16-430 6.00 Circular 0.026 0.38 390 P-16-469.1 5.42 Special 0.026 0.29 136 P-16-487 6.00 Special 0.024 -0.05 84 P-16-495.1 4.83 Special 0.026 -0.19 106 P-16-646 5.00 Circular 0.015 0.34 471 P-16-647 5.00 Circular 0.015 0.33 832 P-40D-22 5.00 Circular 0.015 0.42 43 P-AEW-1.1 4.83 Special 0.016 0.26 589 P-AEW-1.2 4.83 Special 0.016 0.26 587 P-AEW-10 3.00 Rectangular 0.015 0.78 195 P-AEW-13 5.00 Circular 0.015 0.33 278 P-AEW-14 3.00 Trapezoidal 0.100 1.28 16 P-AEW-15 3.17 Special 0.026 2.64 50 P-AEW-16 2.50 Circular 0.015 -0.80 71 P-AEW-3.1 4.00 Circular 0.015 1.22 166 P-AEW-8 4.50 Circular 0.015 0.16 164 P-AP-1 1.25 Circular 0.015 0.40 45 P-LP-1 4.25 Special 0.015 0.26 46 P-STR-10 3.5 Circular 0.015 0.11 75 P-STR-5 3.5 Circular 0.015 0.11 72 P-WM MH-1 1.00 Circular 0.015 0.25 95 P-WM P-1 1.00 Circular 0.015 0.10 290 P-WM P-2 1.25 Circular 0.015 0.60 82 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 1 of 3 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.02-4.doc\052506 TABLE 3.02-4 EXISTING PEAK CHARGES–ELEVATIONS SUMMARY Conduit Name Design Flow (cfs) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) pipe capacity D-40D-1 113.97 -119.29 0.00 119.29 21514.65 779.96 -117.20 0.00 117.20 15327.92 779.88 -114.78 0.00 114.78 9889.06 779.78 -111.44 0.00 111.44 4272.23 779.62 -103.44 0.00 103.44 0.00 779.37 -68.12 0.00 68.12 0.00 778.76 -34.40 0.00 34.40 0.00 778.17 2 D-40D-1.1 109.38 116.92 0.00 116.92 0.00 779.96 115.38 0.00 115.38 0.00 779.88 113.44 0.00 113.44 0.00 779.78 110.13 0.00 110.13 0.00 779.62 103.05 0.00 103.05 0.00 779.37 67.88 0.00 67.88 0.00 778.76 34.22 0.00 34.22 0.00 778.17 10 D-40D-10 439.49 113.14 0.00 113.14 0.00 770.65 110.82 0.00 110.82 0.00 770.61 108.23 0.00 108.23 0.00 770.56 101.66 0.00 101.66 0.00 770.45 92.43 0.00 92.43 0.00 770.29 70.78 0.00 70.78 0.00 769.90 40.32 0.00 40.32 0.00 769.22 >100 D-40D-11 500.27 113.22 0.00 113.22 0.00 770.01 110.94 0.00 110.94 0.00 769.95 108.35 0.00 108.35 0.00 769.88 101.78 0.00 101.78 0.00 769.77 92.48 0.00 92.48 0.00 769.61 70.71 0.00 70.71 0.00 769.22 40.20 0.00 40.20 0.00 768.57 >100 D-40D-12 185.02 127.51 0.00 127.51 0.00 769.24 121.52 0.00 121.52 0.00 769.16 115.28 0.00 115.28 0.00 769.07 105.50 0.00 105.50 0.00 768.94 94.14 0.00 94.14 0.00 768.79 70.68 0.00 70.68 0.00 768.44 40.03 0.00 40.03 0.00 767.88 >100 D-40D-13 194.57 126.87 0.00 126.87 0.00 768.78 121.25 0.00 121.25 0.00 768.69 114.91 0.00 114.91 0.00 768.58 105.27 0.00 105.27 0.00 768.43 93.84 0.00 93.84 0.00 768.25 70.51 0.00 70.51 0.00 767.85 39.83 0.00 39.83 0.00 767.21 25 D-40D-14 148.07 126.72 0.00 126.72 0.00 768.41 121.05 0.00 121.05 0.00 768.31 114.70 0.00 114.70 0.00 768.19 105.15 0.00 105.15 0.00 768.05 93.71 0.00 93.71 0.00 767.87 70.43 0.00 70.43 0.00 767.46 39.71 0.00 39.71 0.00 766.79 >100 D-40D-15 142.30 131.18 0.00 131.18 0.00 767.56 123.34 0.00 123.34 0.00 767.43 112.42 0.00 112.42 0.00 767.28 101.12 0.00 101.12 0.00 767.11 90.19 0.00 90.19 0.00 766.94 65.05 0.00 65.05 0.00 766.51 36.81 0.00 36.81 0.00 765.88 >100 D-40D-16 133.86 130.83 0.00 130.83 0.00 766.52 123.13 0.00 123.13 0.00 766.30 112.34 0.00 112.34 0.00 766.12 101.00 0.00 101.00 0.00 765.93 90.15 0.00 90.15 0.00 765.76 65.03 0.00 65.03 0.00 765.36 36.78 0.00 36.78 0.00 764.79 >100 D-40D-16.1 133.24 80.32 0.00 80.32 0.00 766.02 75.66 0.00 75.66 0.00 765.69 66.49 0.00 66.49 0.00 765.45 54.69 0.00 54.69 0.00 765.19 45.97 0.00 45.97 0.00 764.98 31.20 0.00 31.20 0.00 764.58 15.95 0.00 15.95 0.00 764.01 >100 D-40D-17 143.10 80.94 0.00 80.94 0.00 765.90 76.45 0.00 76.45 0.00 765.51 66.49 0.00 66.49 0.00 765.25 54.67 0.00 54.67 0.00 764.99 45.95 0.00 45.95 0.00 764.78 31.19 0.00 31.19 0.00 764.37 15.93 0.00 15.93 0.00 763.80 >100 D-40D-17.1 143.65 82.37 0.00 82.37 0.00 765.79 78.22 0.00 78.22 0.00 765.34 68.32 0.00 68.32 0.00 765.05 56.27 0.00 56.27 0.00 764.79 47.40 0.00 47.40 0.00 764.58 32.55 0.00 32.55 0.00 764.17 17.32 0.00 17.32 0.00 763.61 >100 D-40D-18 147.55 81.18 0.00 81.18 0.00 765.50 77.76 0.00 77.76 0.00 764.83 68.28 0.00 68.28 0.00 764.45 56.23 0.00 56.23 0.00 764.16 47.36 0.00 47.36 0.00 763.94 32.54 0.00 32.54 0.00 763.53 17.28 0.00 17.28 0.00 762.97 >100 D-40D-19 187.00 89.85 0.00 89.85 0.00 765.28 84.40 0.00 84.40 0.00 764.45 73.06 0.00 73.06 0.00 763.94 59.37 0.00 59.37 0.00 763.63 49.70 0.00 49.70 0.00 763.40 33.49 0.00 33.49 0.00 762.98 17.25 0.00 17.25 0.00 762.43 >100 D-40D-2 178.17 116.58 0.00 116.58 2421.05 779.05 115.04 0.00 115.04 979.54 778.98 113.07 0.00 113.07 0.00 778.90 109.66 0.00 109.66 0.00 778.79 102.37 0.00 102.37 0.00 778.55 67.51 0.00 67.51 0.00 777.69 34.07 0.00 34.07 0.00 777.04 25 D-40D-20 384.02 88.90 0.00 88.90 0.00 765.10 82.71 0.00 82.71 0.00 764.09 72.84 0.00 72.84 0.00 763.28 59.20 0.00 59.20 0.00 762.92 49.55 0.00 49.55 0.00 762.67 33.44 0.00 33.44 0.00 762.24 17.21 0.00 17.21 0.00 761.73 >100 D-40D-21 749.22 92.03 0.00 92.03 0.00 765.06 82.75 0.00 82.75 0.00 763.96 72.71 0.00 72.71 0.00 762.94 59.10 0.00 59.10 0.00 762.48 49.46 0.00 49.46 0.00 762.17 33.38 0.00 33.38 0.00 761.64 17.17 0.00 17.17 0.00 760.99 >100 D-40D-23 731.71 102.92 0.00 102.92 0.00 763.97 89.36 0.00 89.36 0.00 762.79 73.02 0.00 73.02 0.00 761.38 59.19 0.00 59.19 0.00 760.97 49.46 0.00 49.46 0.00 760.73 33.34 0.00 33.34 0.00 760.32 17.10 0.00 17.10 0.00 759.79 >100 D-40D-3 58.69 84.49 0.00 84.49 450342.98 777.72 84.39 0.00 84.39 331430.06 777.65 84.20 0.00 84.20 246736.99 777.59 83.75 0.00 83.75 166183.33 777.51 82.15 0.00 82.15 59499.05 777.30 66.91 0.00 66.91 0.00 776.36 35.51 0.00 35.51 0.00 775.42 2 D-40D-4 89.49 76.46 0.00 76.46 354802.64 777.01 75.78 0.00 75.78 266411.74 776.95 76.01 0.00 76.01 201012.02 776.89 75.56 0.00 75.56 143005.73 776.82 75.16 0.00 75.16 60862.83 776.64 65.91 0.00 65.91 1021.32 775.94 35.35 0.00 35.35 0.00 774.90 1 D-40D-5 50.82 72.06 0.00 72.06 578783.62 776.32 70.38 0.00 70.38 475100.76 776.27 70.55 0.00 70.55 347628.10 776.21 66.57 0.00 66.57 274957.39 776.16 68.76 0.00 68.76 117757.05 775.98 62.05 0.00 62.05 11811.56 775.46 35.26 0.00 35.26 0.00 774.23 1 D-40D-6 53.51 75.27 0.00 75.27 170444.93 775.45 74.60 0.00 74.60 129039.85 775.39 73.59 0.00 73.59 94770.89 775.32 73.60 0.00 73.60 73340.85 775.26 69.86 0.00 69.86 33292.43 775.07 64.73 0.00 64.73 4357.16 774.63 35.36 0.00 35.36 0.00 773.67 1 D-40D-7 154.54 109.35 0.00 109.35 0.00 774.52 108.48 0.00 108.48 0.00 774.48 106.77 0.00 106.77 0.00 774.40 101.06 0.00 101.06 0.00 774.22 92.23 0.00 92.23 0.00 773.93 71.58 0.00 71.58 0.00 773.38 40.87 0.00 40.87 0.00 772.68 >100 D-40D-8 294.79 109.62 0.00 109.62 0.00 774.19 108.65 0.00 108.65 0.00 774.13 106.87 0.00 106.87 0.00 774.04 101.08 0.00 101.08 0.00 773.81 92.16 0.00 92.16 0.00 773.44 71.18 0.00 71.18 0.00 772.73 40.72 0.00 40.72 0.00 771.86 >100 D-40D-9 628.05 113.15 0.00 113.15 0.00 771.25 110.83 0.00 110.83 0.00 771.21 108.24 0.00 108.24 0.00 771.17 101.66 0.00 101.66 0.00 771.06 92.42 0.00 92.42 0.00 770.91 70.88 0.00 70.88 0.00 770.53 40.44 0.00 40.44 0.00 769.85 <1 D-AD-1 803.33 112.05 0.00 112.05 0.00 772.09 107.97 0.00 107.97 0.00 771.92 100.60 0.00 100.60 0.00 771.78 87.30 0.00 87.30 0.00 771.53 70.40 0.00 70.40 0.00 771.22 48.81 0.00 48.81 0.00 770.78 34.05 0.00 34.05 0.00 770.42 >100 D-AD-2 410.10 108.69 0.00 108.69 0.00 771.46 105.71 0.00 105.71 0.00 771.17 99.09 0.00 99.09 0.00 770.85 85.89 0.00 85.89 0.00 770.48 69.59 0.00 69.59 0.00 770.05 48.58 0.00 48.58 0.00 769.48 33.83 0.00 33.83 0.00 769.00 <1 D-AD-3 75.19 120.93 0.00 120.93 0.00 771.28 114.53 0.00 114.53 0.00 770.96 105.69 0.00 105.69 0.00 770.57 89.77 0.00 89.77 0.00 770.15 72.44 0.00 72.44 0.00 769.68 50.26 0.00 50.26 0.00 769.09 34.77 0.00 34.77 0.00 768.58 50 D-AD-4 145.59 119.90 0.00 119.90 7578.27 770.48 112.25 0.00 112.25 1471.13 770.25 104.21 0.00 104.21 0.00 769.83 87.45 0.00 87.45 0.00 769.29 71.38 0.00 71.38 0.00 768.63 50.17 0.00 50.17 0.00 767.98 34.71 0.00 34.71 0.00 767.55 25 D-AD-5 161.85 108.37 0.00 108.37 22278.12 770.14 102.40 0.00 102.40 9947.80 769.94 96.85 0.00 96.85 0.00 769.62 83.40 0.00 83.40 0.00 769.06 68.71 0.00 68.71 0.00 768.27 49.82 0.00 49.82 0.00 767.40 34.59 0.00 34.59 0.00 766.89 10 D-AEW-11 22.68 49.67 0.00 49.67 699.08 765.46 48.43 0.00 48.43 0.00 765.20 48.08 0.00 48.08 0.00 765.05 47.19 0.00 47.19 0.00 764.87 44.10 0.00 44.10 0.00 764.67 33.79 0.00 33.79 0.00 763.91 20.79 0.00 20.79 0.00 763.32 2 D-AEW-12 310.42 96.47 0.00 96.47 0.00 764.04 85.53 0.00 85.53 0.00 762.97 72.75 0.00 72.75 0.00 761.95 59.10 0.00 59.10 0.00 761.58 49.44 0.00 49.44 0.00 761.33 33.35 0.00 33.35 0.00 760.89 17.12 0.00 17.12 0.00 760.29 >100 D-AEW-2 161.87 87.22 0.00 87.22 0.00 758.81 86.58 0.00 86.58 0.00 758.77 85.87 0.00 85.87 0.00 758.72 84.98 0.00 84.98 0.00 758.65 83.49 0.00 83.49 0.00 758.58 76.79 0.00 76.79 0.00 758.35 54.63 0.00 54.63 0.00 757.63 <1 D-AEW-5 113.20 98.59 0.00 98.59 345973.44 778.50 98.02 0.00 98.02 250035.64 778.44 97.16 0.00 97.16 178704.53 778.37 95.56 0.00 95.56 107560.02 778.26 91.87 0.00 91.87 27888.50 777.97 67.78 0.00 67.78 0.00 776.75 35.79 0.00 35.79 0.00 775.87 2 D-AEW-7 101.59 109.12 0.00 109.12 0.00 774.87 108.00 0.00 108.00 0.00 774.82 105.36 0.00 105.36 0.00 774.75 99.32 0.00 99.32 0.00 774.60 90.95 0.00 90.95 0.00 774.35 71.02 0.00 71.02 0.00 773.86 40.72 0.00 40.72 0.00 773.15 <1 D-AEW-9 703.38 113.19 0.00 113.19 0.00 771.82 110.89 0.00 110.89 0.00 771.78 108.29 0.00 108.29 0.00 771.74 101.73 0.00 101.73 0.00 771.64 92.48 0.00 92.48 0.00 771.49 71.03 0.00 71.03 0.00 771.13 40.58 0.00 40.58 0.00 770.46 25 D-DITCH 102.01 87.36 0.00 87.36 0.00 758.33 86.76 0.00 86.76 0.00 758.27 86.06 0.00 86.06 0.00 758.20 85.13 0.00 85.13 0.00 758.09 83.51 0.00 83.51 0.00 757.98 76.49 0.00 76.49 0.00 757.66 54.54 0.00 54.54 0.00 756.60 10 D-D-OF-1 254.67 358.76 0.00 358.76 0.00 750.38 295.22 0.00 295.22 0.00 749.64 251.28 0.00 251.28 0.00 749.40 214.65 0.00 214.65 0.00 748.67 185.14 0.00 185.14 0.00 748.45 151.98 0.00 151.98 0.00 748.22 110.94 0.00 110.94 0.00 747.96 25 D-D-OF-2 222.50 354.32 0.00 354.32 16453.25 749.77 296.03 0.00 296.03 0.00 749.12 251.77 0.00 251.77 0.00 748.73 214.72 0.00 214.72 0.00 748.38 185.21 0.00 185.21 0.00 748.21 151.99 0.00 151.99 0.00 748.02 110.96 0.00 110.96 0.00 747.83 50 D-D-OF-3 772.79 413.23 0.00 413.23 0.00 749.08 351.78 0.00 351.78 0.00 748.67 292.61 0.00 292.61 0.00 748.32 240.75 0.00 240.75 0.00 748.00 202.98 0.00 202.98 0.00 747.89 160.63 0.00 160.63 0.00 747.78 118.43 0.00 118.43 0.00 747.69 <1 D-LP-2 76.72 44.65 0.00 44.65 0.00 764.20 45.07 0.00 45.07 0.00 764.09 45.68 0.00 45.68 0.00 764.01 45.29 0.00 45.29 0.00 763.94 42.72 0.00 42.72 0.00 763.70 33.65 0.00 33.65 0.00 762.89 20.76 0.00 20.76 0.00 762.23 2 D-LP-3 108.34 43.40 0.00 43.40 20923.29 763.97 42.59 0.00 42.59 14546.58 763.88 42.32 0.00 42.32 10050.95 763.80 42.66 0.00 42.66 7602.12 763.75 41.44 0.00 41.44 1179.37 763.50 33.19 0.00 33.19 0.00 762.72 20.70 0.00 20.70 0.00 761.96 2 D-LP-4 37.13 42.82 0.00 42.82 15689.23 763.83 42.03 0.00 42.03 10953.28 763.75 41.59 0.00 41.59 7559.97 763.68 41.38 0.00 41.38 5658.10 763.62 40.43 0.00 40.43 372.33 763.38 32.50 0.00 32.50 0.00 762.60 20.65 0.00 20.65 0.00 761.71 2 D-LP-5 489.97 48.26 0.00 48.26 13194.73 763.49 45.10 0.00 45.10 9562.70 763.43 43.23 0.00 43.23 6531.71 763.36 40.29 0.00 40.29 4994.30 763.31 39.24 0.00 39.24 0.00 763.06 31.34 0.00 31.34 0.00 762.23 20.60 0.00 20.60 0.00 760.56 5 D-LP-6 67.99 44.66 0.00 44.66 11829.24 763.48 43.00 0.00 43.00 8483.51 763.43 41.62 0.00 41.62 5696.60 763.35 39.63 0.00 39.63 4317.23 763.30 38.62 0.00 38.62 0.00 763.05 30.89 0.00 30.89 0.00 762.22 20.56 0.00 20.56 0.00 760.20 5 O-AEW-13 34.68 12.55 0.00 12.55 0.00 763.92 0.00 0.00 0.00 0.00 762.62 0.00 0.00 0.00 0.00 762.02 0.00 0.00 0.00 0.00 761.10 0.00 0.00 0.00 0.00 760.57 0.00 0.00 0.00 0.00 760.27 0.00 0.00 0.00 0.00 760.27 >100 P-06-1062 40.97 -30.79 0.00 30.79 27735.13 760.35 27.04 0.00 27.04 12638.75 760.20 26.98 0.00 26.98 2514.43 759.92 26.90 0.00 26.90 0.00 759.64 26.77 0.00 26.77 0.00 759.51 26.41 0.00 26.41 0.00 759.24 23.97 0.00 23.97 0.00 755.83 10 P-06-1282 62.21 51.40 0.00 51.40 0.00 765.61 50.17 0.00 50.17 0.00 765.33 48.67 0.00 48.67 0.00 765.17 47.58 0.00 47.58 0.00 764.99 44.15 0.00 44.15 0.00 764.78 33.80 0.00 33.80 0.00 763.98 20.80 0.00 20.80 0.00 763.35 >100 P-06-1293 16.94 32.00 0.00 32.00 256713.86 762.79 32.02 0.00 32.02 211810.80 762.75 31.96 0.00 31.96 148877.85 762.68 32.03 0.00 32.03 116692.31 762.63 31.48 0.00 31.48 41284.59 762.43 28.92 0.00 28.92 361.31 761.76 30.38 0.00 30.38 0.00 759.84 1 P06-1293.1 2.98 3.04 0.00 3.04 61022.93 761.99 3.03 0.00 3.03 57531.27 761.98 3.79 0.00 3.79 47102.38 761.94 3.78 0.00 3.78 35485.53 761.89 3.60 0.00 3.60 17048.86 761.75 3.02 0.00 3.02 2328.90 761.42 2.80 0.00 2.80 0.00 760.16 1 P-06-1293.2 1.10 3.04 0.00 3.04 99590.74 761.51 3.03 0.00 3.03 93818.38 761.50 3.00 0.00 3.00 87866.67 761.49 2.99 0.00 2.99 70142.69 761.44 3.12 0.00 3.12 37533.62 761.32 2.97 0.00 2.97 12950.70 761.11 2.81 0.00 2.81 16.76 760.63 <1 P-06-1353 35.60 12.09 0.00 12.09 0.00 763.44 -8.81 0.00 8.81 0.00 762.57 -7.64 0.00 7.64 0.00 762.07 -4.46 0.00 4.46 0.00 761.83 -2.10 0.00 2.10 0.00 761.35 -0.07 0.00 0.07 0.00 760.94 0.00 0.00 0.00 0.00 760.84 >100 P-06-1354 9.34 12.09 0.00 12.09 0.00 763.31 -8.81 0.00 8.81 0.00 762.56 -7.64 0.00 7.64 0.00 762.19 -4.47 0.00 4.47 0.00 761.87 -2.10 0.00 2.10 0.00 761.39 -0.28 0.00 0.28 0.00 760.94 -0.14 0.00 0.14 0.00 760.66 >100 P-06-1355 9.16 14.86 0.00 14.86 33509.29 762.79 14.51 0.00 14.51 11180.67 762.61 13.88 0.00 13.88 3113.18 762.40 12.04 0.00 12.04 0.00 761.90 10.17 0.00 10.17 0.00 761.41 8.13 0.00 8.13 0.00 760.94 5.51 0.00 5.51 0.00 760.66 10 P-06-1356 20.32 14.86 0.00 14.86 0.00 761.10 14.51 0.00 14.51 0.00 760.96 13.88 0.00 13.88 0.00 760.85 12.04 0.00 12.04 0.00 760.72 10.17 0.00 10.17 0.00 760.58 8.12 0.00 8.12 0.00 760.43 5.51 0.00 5.51 0.00 760.22 >100 P-06-1357 23.92 14.82 0.00 14.82 0.00 760.91 14.49 0.00 14.49 0.00 760.76 13.87 0.00 13.87 0.00 760.64 12.00 0.00 12.00 0.00 760.54 10.18 0.00 10.18 0.00 760.41 8.13 0.00 8.13 0.00 760.28 5.49 0.00 5.49 0.00 760.10 >100 P-06-1370 144.18 94.26 0.00 94.26 0.00 764.89 84.07 0.00 84.07 0.00 763.58 72.71 0.00 72.71 0.00 762.48 59.09 0.00 59.09 0.00 762.00 49.45 0.00 49.45 0.00 761.68 33.37 0.00 33.37 0.00 761.11 17.15 0.00 17.15 0.00 760.41 >100 P-06-1371 145.34 94.31 0.00 94.31 0.00 764.42 84.15 0.00 84.15 0.00 763.21 72.71 0.00 72.71 0.00 762.15 59.09 0.00 59.09 0.00 761.73 49.44 0.00 49.44 0.00 761.46 33.36 0.00 33.36 0.00 760.96 17.14 0.00 17.14 0.00 760.32 >100 P-06-1387 3.75 2.10 0.00 2.10 0.00 766.64 2.25 0.00 2.25 0.00 766.11 2.25 0.00 2.25 0.00 765.75 2.26 0.00 2.26 0.00 765.35 2.11 0.00 2.11 0.00 765.02 1.58 0.00 1.58 0.00 764.55 1.43 0.00 1.43 0.00 764.00 >100 P-06-1388 2.11 2.10 0.00 2.10 0.00 766.35 2.26 0.00 2.26 0.00 765.85 2.26 0.00 2.26 0.00 765.52 2.27 0.00 2.27 0.00 765.14 2.13 0.00 2.13 0.00 764.87 1.58 0.00 1.58 0.00 764.42 1.43 0.00 1.43 0.00 763.88 >100 P-06-1389 3.17 2.10 0.00 2.10 0.00 765.94 2.27 0.00 2.27 0.00 765.48 2.27 0.00 2.27 0.00 765.18 2.29 0.00 2.29 0.00 764.88 2.15 0.00 2.15 0.00 764.66 1.63 0.00 1.63 0.00 764.24 1.45 0.00 1.45 0.00 763.68 >100 P-06-1391 46.05 5.26 0.00 5.26 0.00 767.58 3.22 0.00 3.22 0.00 767.43 -3.52 0.00 3.52 0.00 767.27 -3.96 0.00 3.96 0.00 767.10 -3.46 0.00 3.46 0.00 766.93 -5.38 0.00 5.38 0.00 766.51 -2.86 0.00 2.86 0.00 765.88 >100 P-06-1392 70.14 5.27 0.00 5.27 0.00 767.57 3.22 0.00 3.22 0.00 767.43 -3.52 0.00 3.52 0.00 767.28 -3.96 0.00 3.96 0.00 767.10 -3.46 0.00 3.46 0.00 766.94 -5.41 0.00 5.41 0.00 766.50 -2.86 0.00 2.86 0.00 765.88 >100 P-06-408.1 31.18 34.63 137.42 172.05 0.00 753.51 40.55 113.14 153.69 0.00 753.36 35.75 92.11 127.86 0.00 753.22 34.82 69.94 104.76 0.00 753.05 34.66 53.25 87.91 0.00 752.93 34.81 30.80 65.61 0.00 752.75 29.88 0.00 29.88 0.00 752.18 1 P-06-408.2 31.28 33.81 0.00 33.81 0.00 753.51 39.69 0.00 39.69 0.00 753.36 34.89 0.00 34.89 0.00 753.22 33.98 0.00 33.98 0.00 753.05 33.84 0.00 33.84 0.00 752.93 33.97 0.00 33.97 0.00 752.75 29.16 0.00 29.16 0.00 752.18 1 P-06-462.1 34.33 42.76 83.68 126.44 396260.25 752.30 43.78 38.57 82.35 378743.58 752.29 44.43 33.57 78.00 271172.72 752.22 44.74 26.11 70.85 151441.67 752.09 44.60 20.23 64.83 85708.36 751.96 42.69 8.87 51.56 17712.23 751.58 32.06 0.00 32.06 0.00 749.62 1 P-06-462.2 34.24 42.66 0.00 42.66 0.00 752.30 43.68 0.00 43.68 0.00 752.29 44.33 0.00 44.33 0.00 752.22 44.63 0.00 44.63 0.00 752.09 44.49 0.00 44.49 0.00 751.96 42.59 0.00 42.59 0.00 751.58 31.98 0.00 31.98 0.00 749.62 1 P-06-467.1 25.11 28.71 110.85 139.56 259868.38 753.20 33.95 103.38 137.33 160752.04 753.10 29.09 96.55 125.64 79879.69 752.95 32.00 90.02 122.02 24654.19 752.71 27.91 84.31 112.22 8469.11 752.49 28.82 67.88 96.70 824.46 752.18 28.95 4.89 33.84 0.00 751.64 <1 P-06-467.2 25.11 28.71 0.00 28.71 0.00 753.20 33.95 0.00 33.95 0.00 753.10 29.09 0.00 29.09 0.00 752.95 32.00 0.00 32.00 0.00 752.71 27.91 0.00 27.91 0.00 752.49 28.82 0.00 28.82 0.00 752.18 28.95 0.00 28.95 0.00 751.64 <1 P-06-469.1 29.83 39.18 69.05 108.23 0.00 753.39 37.36 50.14 87.50 0.00 753.29 36.23 34.35 70.58 0.00 753.20 35.79 20.01 55.80 0.00 753.10 34.90 4.34 39.24 0.00 752.95 31.80 0.00 31.80 0.00 752.71 24.55 0.00 24.55 0.00 751.21 2 P-06-470.1 26.36 31.51 164.23 195.74 0.00 753.63 33.76 133.81 167.57 0.00 753.51 32.94 102.64 135.58 0.00 753.49 31.45 67.76 99.21 0.00 753.58 31.41 54.33 85.74 0.00 753.49 32.08 35.51 67.59 0.00 753.36 29.98 0.00 29.98 0.00 752.85 1 P-06-470.2 26.34 31.49 0.00 31.49 0.00 753.63 33.74 0.00 33.74 0.00 753.51 32.92 0.00 32.92 0.00 753.49 31.43 0.00 31.43 0.00 753.58 31.39 0.00 31.39 0.00 753.49 32.06 0.00 32.06 0.00 753.36 29.96 0.00 29.96 0.00 752.85 1 P-06-471.1 20.97 37.82 156.43 194.25 0.00 754.10 35.36 126.94 162.30 0.00 754.01 35.34 101.17 136.51 0.00 754.06 31.67 82.62 114.29 0.00 754.07 30.60 69.63 100.23 0.00 754.00 29.19 46.14 75.33 0.00 754.05 28.70 9.49 38.19 0.00 753.67 <1 P-06-471.2 20.99 37.76 0.00 37.76 0.00 754.10 35.31 0.00 35.31 0.00 754.01 35.30 0.00 35.30 0.00 754.06 31.63 0.00 31.63 0.00 754.07 30.56 0.00 30.56 0.00 754.00 29.15 0.00 29.15 0.00 754.05 28.66 0.00 28.66 0.00 753.67 <1 P-06-472.1 39.75 38.30 45.18 83.48 0.00 755.03 31.35 33.67 65.02 0.00 754.96 31.92 35.50 67.42 0.00 755.00 32.21 26.84 59.05 0.00 754.94 32.49 20.95 53.44 0.00 754.89 30.02 14.30 44.32 0.00 754.83 27.02 0.43 27.45 0.00 754.57 <1 P-06-473.1 35.77 55.51 16.84 72.35 0.00 755.73 53.08 3.43 56.51 0.00 755.61 47.17 0.00 47.17 0.00 755.51 42.14 0.00 42.14 0.00 755.34 39.15 0.00 39.15 0.00 755.24 34.36 0.00 34.36 0.00 755.10 27.04 0.00 27.04 0.00 754.73 25 P-06-473.2 86.12 104.52 0.00 104.52 0.00 755.73 96.98 0.00 96.98 0.00 755.61 86.91 0.00 86.91 0.00 755.51 73.94 0.00 73.94 0.00 755.34 65.95 0.00 65.95 0.00 755.24 55.15 0.00 55.15 0.00 755.10 34.08 0.00 34.08 0.00 754.73 25 P-06-474.1 43.56 55.13 0.00 55.13 178853.34 757.15 53.48 0.00 53.48 113809.53 757.04 51.00 0.00 51.00 71451.42 756.92 48.08 0.00 48.08 33316.25 756.71 45.95 0.00 45.95 16708.52 756.52 40.63 0.00 40.63 0.00 756.11 28.84 0.00 28.84 0.00 755.22 2 P-06-474.2 46.04 55.12 0.00 55.12 0.00 757.15 53.47 0.00 53.47 0.00 757.04 50.99 0.00 50.99 0.00 756.92 48.07 0.00 48.07 0.00 756.71 45.94 0.00 45.94 0.00 756.52 40.62 0.00 40.62 0.00 756.11 28.84 0.00 28.84 0.00 755.22 2 P-06-486.1 19.06 38.70 53.04 91.74 0.00 755.41 38.82 37.48 76.30 0.00 755.33 38.70 24.74 63.44 0.00 755.25 38.62 14.52 53.14 0.00 755.18 37.16 0.00 37.16 0.00 754.92 31.66 0.00 31.66 0.00 754.03 23.43 0.00 23.43 0.00 751.99 5 P-06-487.1 24.38 39.77 67.92 107.69 0.00 755.75 38.32 53.36 91.68 0.00 755.67 37.35 44.01 81.36 0.00 755.62 35.79 34.44 70.23 0.00 755.54 34.65 9.32 43.97 0.00 755.43 31.35 0.00 31.35 0.00 754.63 24.07 0.00 24.07 0.00 752.35 2 P-06-489.1 66.68 85.38 -468.26 553.64 0.00 751.54 79.34 -468.26 547.60 0.00 750.59 77.36 -468.26 545.62 0.00 750.38 73.95 -468.26 542.21 0.00 749.84 70.03 -468.26 538.29 0.00 749.65 61.41 -468.26 529.67 0.00 749.24 42.73 -468.26 510.99 0.00 748.42 <1 P-06-489.2 63.29 88.18 0.00 88.18 0.00 751.54 81.96 0.00 81.96 0.00 750.59 79.91 0.00 79.91 0.00 750.38 76.39 0.00 76.39 0.00 749.84 72.34 0.00 72.34 0.00 749.65 63.44 0.00 63.44 0.00 749.24 45.26 0.00 45.26 0.00 748.42 <1 5 year 2 year 1year100year 50 year 25 year 10 year City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 2 of 3 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.02-4.doc\052506 TABLE 3.02-4 (CONTINUED) EXISTING PEAK CHARGES–ELEVATIONS SUMMARY Conduit Name Design Flow (cfs) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) pipe capacity 5 year 2 year 1year100year 50 year 25 year 10 year P-06-490 33.26 46.86 0.00 46.86 136855.78 752.03 39.25 0.00 39.25 78389.58 751.92 39.08 0.00 39.08 45104.08 751.81 38.27 0.00 38.27 13561.92 751.58 36.25 0.00 36.25 2128.84 751.27 31.07 0.00 31.07 0.00 750.45 24.41 0.00 24.41 0.00 749.13 2 P-06-492.1 17.80 37.23 49.20 86.43 215147.44 752.04 31.86 45.11 76.97 125800.55 751.92 30.81 40.34 71.15 74918.16 751.81 30.87 36.76 67.63 25661.20 751.58 31.00 32.84 63.84 6178.74 751.28 30.97 15.87 46.84 0.00 750.47 24.44 0.00 24.44 0.00 749.22 1 P-06-493.1 6.75 32.79 83.62 116.41 1239.39 752.37 32.78 66.37 99.15 0.00 752.20 33.11 51.63 84.74 0.00 752.06 32.51 35.11 67.62 0.00 751.86 32.03 22.85 54.88 0.00 751.71 30.77 8.42 39.19 0.00 751.53 24.54 0.00 24.54 0.00 750.42 1 P-06-494.1 32.64 37.35 78.86 116.21 0.00 752.68 33.04 59.64 92.68 0.00 752.56 31.37 43.28 74.65 0.00 752.44 33.58 26.00 59.58 0.00 752.30 32.15 11.96 44.11 0.00 752.17 30.81 3.27 34.08 0.00 752.06 24.54 0.00 24.54 0.00 750.82 >100 P-06-552.1 28.06 42.39 73.02 115.41 0.00 756.14 39.39 54.21 93.60 0.00 756.19 37.51 41.23 78.74 0.00 756.10 35.05 29.20 64.25 0.00 756.01 34.00 19.53 53.53 0.00 755.91 31.47 1.54 33.01 0.00 755.68 24.85 0.00 24.85 0.00 753.05 >100 P-06-553.1 26.43 29.52 39.91 69.43 0.00 756.88 30.50 32.47 62.97 0.00 756.83 30.15 24.01 54.16 0.00 756.76 30.17 14.46 44.63 0.00 756.67 29.46 9.01 38.47 0.00 756.61 27.93 0.49 28.42 0.00 756.45 22.83 0.00 22.83 0.00 753.51 >100 P-06-602.1 11.48 31.47 107.20 138.67 53245.84 753.13 28.17 100.79 128.96 35451.37 753.04 29.14 96.03 125.17 19261.49 752.90 29.71 88.34 118.05 6404.50 752.66 29.13 81.54 110.67 1014.25 752.45 31.93 60.36 92.29 0.00 752.14 31.28 0.00 31.28 0.00 751.42 1 P-06-602.2 11.95 31.42 0.00 31.42 0.00 753.13 28.18 0.00 28.18 0.00 753.04 29.13 0.00 29.13 0.00 752.90 29.69 0.00 29.69 0.00 752.66 29.11 0.00 29.11 0.00 752.45 31.93 0.00 31.93 0.00 752.14 31.29 0.00 31.29 0.00 751.42 1 P-06-640.1 7.48 29.54 47.78 77.32 0.00 756.53 29.58 35.26 64.84 0.00 756.43 29.05 24.92 53.97 0.00 756.33 28.56 12.59 41.15 0.00 756.19 27.11 0.00 27.11 0.00 755.72 17.74 0.00 17.74 0.00 751.19 11.53 0.00 11.53 0.00 750.70 5 P-06-653.1 15.85 35.18 44.61 79.79 0.00 757.45 33.66 35.65 69.31 0.00 757.38 33.04 27.70 60.74 0.00 757.30 31.96 18.80 50.76 0.00 757.21 31.60 13.61 45.21 0.00 757.14 30.86 5.95 36.81 0.00 757.02 23.28 0.00 23.28 0.00 754.04 1 P-06-677.1 42.03 25.46 0.00 25.46 0.00 756.69 24.30 0.00 24.30 0.00 756.60 27.66 0.00 27.66 0.00 756.50 18.85 0.00 18.85 0.00 756.35 14.96 0.00 14.96 0.00 755.83 9.41 0.00 9.41 0.00 751.38 6.10 0.00 6.10 0.00 750.96 >100 P-06-678 25.34 25.43 0.00 25.43 95637.57 758.25 23.98 0.00 23.98 54233.40 758.14 25.08 0.00 25.08 23434.54 757.98 18.83 0.00 18.83 2025.53 757.54 15.04 0.00 15.04 0.00 756.58 9.42 0.00 9.42 0.00 753.91 6.10 0.00 6.10 0.00 753.67 5 P-06-679 25.68 14.63 0.00 14.63 2546.23 758.93 14.48 0.00 14.48 0.00 758.69 16.06 0.00 16.06 0.00 758.34 11.89 0.00 11.89 0.00 758.27 10.17 0.00 10.17 0.00 756.70 8.11 0.00 8.11 0.00 755.72 5.51 0.00 5.51 0.00 755.54 50 P-06-680 24.34 14.79 0.00 14.79 0.00 759.78 14.49 0.00 14.49 0.00 759.44 13.93 0.00 13.93 0.00 758.89 11.89 0.00 11.89 0.00 758.16 10.17 0.00 10.17 0.00 758.01 8.11 0.00 8.11 0.00 757.88 5.49 0.00 5.49 0.00 757.69 >100 P-06-684 15.64 34.30 0.00 34.30 0.00 758.24 32.98 0.00 32.98 0.00 758.14 31.21 0.00 31.21 0.00 758.00 30.95 0.00 30.95 0.00 757.80 31.36 0.00 31.36 0.00 757.67 28.98 0.00 28.98 0.00 757.41 21.73 0.00 21.73 0.00 754.28 >100 P-06-685.1 22.43 36.15 20.35 56.50 22667.57 759.90 38.61 18.37 56.98 10395.37 759.71 36.84 16.30 53.14 0.00 759.37 33.87 13.45 47.32 0.00 759.02 32.55 8.52 41.07 0.00 758.85 28.77 0.97 29.74 0.00 758.60 21.90 0.00 21.90 0.00 755.25 1 P-06-686 10.92 41.23 0.00 41.23 0.00 760.11 39.04 0.00 39.04 0.00 759.94 37.10 0.00 37.10 0.00 759.58 33.21 0.00 33.21 0.00 759.30 32.60 0.00 32.60 0.00 759.14 28.87 0.00 28.87 0.00 758.88 22.10 0.00 22.10 0.00 755.49 >100 P-06-687 141.91 44.04 0.00 44.04 0.00 760.42 38.79 0.00 38.79 0.00 760.25 37.83 0.00 37.83 0.00 759.95 33.21 0.00 33.21 0.00 759.63 33.07 0.00 33.07 0.00 759.49 29.06 0.00 29.06 0.00 759.21 26.03 0.00 26.03 0.00 755.76 >100 P-06-687.1 10.32 41.65 0.00 41.65 35297.63 760.35 38.97 0.00 38.97 15981.12 760.20 37.43 0.00 37.43 2608.67 759.88 32.74 0.00 32.74 0.00 759.58 32.82 0.00 32.82 0.00 759.44 28.96 0.00 28.96 0.00 759.16 22.40 0.00 22.40 0.00 755.76 10 P-06-688.1 9.08 49.81 27.04 76.85 0.00 764.06 49.52 8.99 58.51 0.00 763.94 43.73 0.00 43.73 0.00 762.99 29.83 0.00 29.83 0.00 760.95 22.03 0.00 22.03 0.00 760.06 14.48 0.00 14.48 0.00 759.36 9.26 0.00 9.26 0.00 755.77 25 P-06-770 17.04 35.14 0.00 35.14 33128.61 759.89 35.11 0.00 35.11 15459.77 759.70 34.10 0.00 34.10 2130.48 759.37 34.02 0.00 34.02 0.00 758.97 32.50 0.00 32.50 0.00 758.68 29.24 0.00 29.24 0.00 758.17 21.82 0.00 21.82 0.00 754.81 10 P-06-773.1 130.14 116.55 0.00 116.55 0.00 763.64 109.43 0.00 109.43 0.00 762.31 94.08 0.00 94.08 0.00 760.34 72.81 0.00 72.81 0.00 759.65 58.66 0.00 58.66 0.00 759.17 35.70 0.00 35.70 0.00 758.34 17.10 0.00 17.10 0.00 757.43 >100 P-06-836.1 36.54 46.31 82.69 129.00 0.00 755.18 36.71 66.55 103.26 0.00 755.13 34.83 62.41 97.24 0.00 755.12 38.69 47.74 86.43 0.00 755.06 39.68 38.18 77.86 0.00 755.01 33.86 26.74 60.60 0.00 754.95 32.69 2.15 34.84 0.00 754.67 <1 P-06-837.1 42.53 28.31 120.47 148.78 0.00 754.95 28.94 96.95 125.89 0.00 754.87 29.35 75.53 104.88 0.00 754.97 29.42 60.78 90.20 0.00 754.89 29.43 49.83 79.26 0.00 754.82 29.24 38.57 67.81 0.00 754.75 28.82 5.77 34.59 0.00 754.43 <1 P-06-837.2 42.55 28.32 0.00 28.32 0.00 754.95 28.95 0.00 28.95 0.00 754.87 29.36 0.00 29.36 0.00 754.97 29.44 0.00 29.44 0.00 754.89 29.44 0.00 29.44 0.00 754.82 29.25 0.00 29.25 0.00 754.75 28.84 0.00 28.84 0.00 754.43 <1 P-06-841 29.28 38.27 0.00 38.27 0.00 760.28 36.64 0.00 36.64 0.00 760.24 35.77 0.00 35.77 0.00 760.18 34.28 0.00 34.28 0.00 760.12 33.27 0.00 33.27 0.00 760.02 28.92 0.00 28.92 0.00 759.71 25.91 0.00 25.91 0.00 756.36 >100 P-06-841.1 20.08 -28.47 0.00 28.47 860833.58 760.05 27.04 0.00 27.04 711901.84 760.01 26.98 0.00 26.98 548642.68 759.96 26.90 0.00 26.90 398456.22 759.90 26.77 0.00 26.77 239237.74 759.80 26.41 0.00 26.41 62366.28 759.53 24.81 0.00 24.81 0.00 756.21 1 P-06-842 25.90 32.00 0.00 32.00 0.00 760.68 32.02 0.00 32.02 0.00 760.64 31.96 0.00 31.96 0.00 760.58 32.03 0.00 32.03 0.00 760.52 31.46 0.00 31.46 0.00 760.41 28.92 0.00 28.92 0.00 760.04 29.53 0.00 29.53 0.00 756.92 >100 P-06-843 11.82 17.91 0.00 17.91 0.00 760.72 17.46 0.00 17.46 0.00 760.60 17.04 0.00 17.04 0.00 760.42 16.39 0.00 16.39 0.00 760.24 15.47 0.00 15.47 0.00 760.53 12.71 0.00 12.71 0.00 759.70 9.46 0.00 9.46 0.00 756.72 >100 P-06-844 8.80 15.35 0.00 15.35 0.00 760.73 15.25 0.00 15.25 0.00 760.63 15.23 0.00 15.23 0.00 760.50 14.40 0.00 14.40 0.00 760.32 13.47 0.00 13.47 0.00 760.37 11.24 0.00 11.24 0.00 759.73 8.12 0.00 8.12 0.00 757.26 >100 P-06-845 12.16 17.37 0.00 17.37 0.00 760.74 15.66 0.00 15.66 0.00 760.64 15.32 0.00 15.32 0.00 760.52 14.61 0.00 14.61 0.00 760.35 13.76 0.00 13.76 0.00 760.35 11.47 0.00 11.47 0.00 759.77 8.15 0.00 8.15 0.00 757.39 >100 P-06-846 9.42 17.73 0.00 17.73 49162.92 760.79 16.08 0.00 16.08 33576.82 760.71 15.34 0.00 15.34 24110.21 760.61 14.75 0.00 14.75 23083.04 760.46 13.84 0.00 13.84 12536.89 760.30 11.57 0.00 11.57 0.00 759.92 8.25 0.00 8.25 0.00 757.77 2 P-06-847 6.71 7.74 0.00 7.74 37370.33 760.86 7.96 0.00 7.96 27214.22 760.80 7.84 0.00 7.84 19545.71 760.72 7.75 0.00 7.75 12900.46 760.61 7.14 0.00 7.14 6773.69 760.48 6.21 0.00 6.21 7.82 760.15 4.84 0.00 4.84 0.00 758.72 1 P-06-848 7.56 -2.28 0.00 2.28 0.00 760.79 -1.86 0.00 1.86 0.00 760.71 -1.46 0.00 1.46 0.00 760.61 1.58 0.00 1.58 0.00 760.51 1.20 0.00 1.20 0.00 760.51 1.18 0.00 1.18 0.00 759.95 -0.46 0.00 0.46 0.00 757.77 >100 P-13-1216. 62.91 73.07 0.00 73.07 48455.94 777.40 68.65 0.00 68.65 18396.56 777.22 59.10 0.00 59.10 594.72 776.73 52.53 0.00 52.53 0.00 775.55 46.02 0.00 46.02 0.00 774.08 36.10 0.00 36.10 0.00 772.96 27.79 0.00 27.79 0.00 772.52 10 P-13-1217 58.03 113.01 0.00 113.01 0.00 776.86 109.01 0.00 109.01 0.00 776.39 101.08 0.00 101.08 0.00 775.67 87.79 0.00 87.79 0.00 774.52 70.77 0.00 70.77 0.00 773.42 48.88 0.00 48.88 0.00 772.40 34.15 0.00 34.15 0.00 771.78 >100 P-13-1218 85.19 113.00 0.00 113.00 0.00 775.11 109.01 0.00 109.01 0.00 774.76 101.07 0.00 101.07 0.00 774.24 87.73 0.00 87.73 0.00 773.53 70.73 0.00 70.73 0.00 772.68 48.88 0.00 48.88 0.00 771.86 34.14 0.00 34.14 0.00 771.30 >100 P-13-1219 78.21 112.98 0.00 112.98 0.00 773.67 108.95 0.00 108.95 0.00 773.43 101.04 0.00 101.04 0.00 773.16 87.70 0.00 87.70 0.00 772.66 70.75 0.00 70.75 0.00 772.05 48.87 0.00 48.87 0.00 771.38 34.14 0.00 34.14 0.00 770.88 >100 P-13-1220 60.87 42.48 0.00 42.48 0.00 779.05 41.94 0.00 41.94 0.00 778.72 41.18 0.00 41.18 0.00 778.08 39.25 0.00 39.25 0.00 776.77 37.45 0.00 37.45 0.00 775.55 32.17 0.00 32.17 0.00 775.29 25.58 0.00 25.58 0.00 775.03 >100 P-13-1221. 63.12 65.27 0.49 65.76 0.00 779.02 61.95 0.00 61.95 0.00 778.69 58.39 0.00 58.39 0.00 777.97 52.42 0.00 52.42 0.00 776.63 45.93 0.00 45.93 0.00 774.84 36.16 0.00 36.16 0.00 774.10 27.84 0.00 27.84 0.00 773.76 50 P13-1703.1 0.76 2.68 13.94 16.62 2904.79 778.80 2.79 8.54 11.33 229.99 778.61 3.18 4.05 7.23 0.00 778.24 2.85 2.25 5.10 0.00 778.05 2.78 -1.66 4.44 0.00 777.72 2.30 0.00 2.30 0.00 776.87 1.60 0.00 1.60 0.00 776.12 2 P13-1703.2 0.80 2.81 0.00 2.81 0.00 778.80 2.93 0.00 2.93 0.00 778.61 3.35 0.00 3.35 0.00 778.24 2.98 0.00 2.98 0.00 778.05 2.93 0.00 2.93 0.00 777.72 2.42 0.00 2.42 0.00 776.87 1.68 0.00 1.68 0.00 776.12 2 P13-1704.1 3.13 6.91 0.00 6.91 272813.57 778.37 6.76 0.00 6.76 187298.04 778.30 6.54 0.00 6.54 121284.57 778.21 5.78 0.00 5.78 62745.35 778.08 3.89 0.00 3.89 17167.95 777.83 2.01 0.00 2.01 0.00 776.76 1.56 0.00 1.56 0.00 775.91 2 P13-1704.2 3.14 6.92 0.00 6.92 0.00 778.37 6.77 0.00 6.77 0.00 778.30 6.55 0.00 6.55 0.00 778.21 5.80 0.00 5.80 0.00 778.08 3.90 0.00 3.90 0.00 777.83 2.01 0.00 2.01 0.00 776.76 1.56 0.00 1.56 0.00 775.91 2 P-13-2371 64.71 113.20 0.00 113.20 0.00 773.03 110.92 0.00 110.92 0.00 772.96 108.32 0.00 108.32 0.00 772.88 101.76 0.00 101.76 0.00 772.68 92.52 0.00 92.52 0.00 772.36 71.10 0.00 71.10 0.00 771.77 40.63 0.00 40.63 0.00 770.85 >100 P-13-2381 57.20 63.14 0.00 63.14 0.00 776.10 62.23 0.00 62.23 0.00 776.01 60.20 0.00 60.20 0.00 775.85 54.43 0.00 54.43 0.00 775.45 44.54 0.00 44.54 0.00 775.46 33.65 0.00 33.65 0.00 773.98 18.11 0.00 18.11 0.00 773.16 >100 P-13-2382 103.98 62.84 0.00 62.84 5088.64 775.34 61.79 0.00 61.79 3245.36 775.28 60.00 0.00 60.00 1443.41 775.17 54.42 0.00 54.42 0.00 774.92 44.54 0.00 44.54 0.00 774.63 33.54 0.00 33.54 0.00 773.91 18.02 0.00 18.02 0.00 773.15 10 P-13-2411. 27.09 42.47 8.47 50.94 0.00 779.06 41.93 0.00 41.93 0.00 778.77 41.17 0.00 41.17 0.00 778.27 39.23 0.00 39.23 0.00 776.96 37.44 0.00 37.44 0.00 776.45 32.17 0.00 32.17 0.00 775.97 25.58 0.00 25.58 0.00 775.47 50 P-13-420 35.99 87.19 0.00 87.19 875952.27 763.00 86.53 0.00 86.53 613735.62 762.93 85.82 0.00 85.82 411919.41 762.85 84.93 0.00 84.93 209163.83 762.71 83.49 0.00 83.49 80521.19 762.51 76.89 0.00 76.89 97.33 761.68 54.66 0.00 54.66 0.00 759.31 1 P-13-452 72.94 -5.09 0.00 5.09 0.00 759.19 -4.74 0.00 4.74 0.00 759.15 4.96 0.00 4.96 0.00 759.10 -3.48 0.00 3.48 0.00 759.02 6.17 0.00 6.17 0.00 758.94 -1.58 0.00 1.58 0.00 758.65 -1.13 0.00 1.13 0.00 757.80 >100 P-13-456.1 36.51 53.46 118.08 171.54 0.00 763.77 53.52 98.63 152.15 0.00 763.88 54.82 85.17 139.99 0.00 763.82 54.29 64.86 119.15 0.00 763.71 53.56 46.62 100.18 0.00 763.60 50.87 15.21 66.08 0.00 763.41 39.49 0.00 39.49 0.00 761.06 1 P-13-457.1 70.94 88.70 64.58 153.28 0.00 765.31 83.81 51.15 134.96 0.00 765.25 83.23 37.53 120.76 0.00 765.18 81.74 18.24 99.98 0.00 765.04 77.74 1.88 79.62 0.00 764.82 57.17 0.00 57.17 0.00 764.05 39.68 0.00 39.68 0.00 761.35 2 P-13-458.1 79.84 64.40 69.60 134.00 4591.68 765.45 61.96 64.26 126.22 3478.23 765.41 62.16 57.21 119.37 2211.18 765.35 61.80 42.44 104.24 83.95 765.22 59.66 21.38 81.04 0.00 765.03 56.04 0.00 56.04 0.00 764.41 35.36 0.00 35.36 0.00 761.50 2 P-13-459.1 80.82 60.90 57.11 118.01 0.00 766.36 63.72 50.53 114.25 0.00 766.31 59.56 43.27 102.83 0.00 766.25 69.26 28.17 97.43 0.00 766.15 59.96 11.03 70.99 0.00 766.00 50.68 0.00 50.68 0.00 765.05 35.32 0.00 35.32 0.00 762.27 2 P-13-460.1 81.49 80.71 33.99 114.70 0.00 768.04 79.15 27.11 106.26 0.00 768.00 79.72 19.82 99.54 0.00 767.94 78.27 6.10 84.37 0.00 767.81 68.41 0.00 68.41 0.00 767.27 51.64 0.00 51.64 0.00 765.69 35.65 0.00 35.65 0.00 763.56 5 P-13-471 78.59 87.20 0.00 87.20 0.00 759.19 86.56 0.00 86.56 0.00 759.15 85.84 0.00 85.84 0.00 759.10 84.95 0.00 84.95 0.00 759.02 83.49 0.00 83.49 0.00 758.94 76.84 0.00 76.84 0.00 758.65 54.64 0.00 54.64 0.00 757.80 >100 P-13-546.1 4.13 6.92 0.00 6.92 1853.07 778.41 6.77 0.00 6.77 932.60 778.34 6.55 0.00 6.55 249.06 778.26 5.80 0.00 5.80 0.00 778.13 3.90 0.00 3.90 0.00 777.87 1.97 0.00 1.97 0.00 776.76 1.54 0.00 1.54 0.00 775.90 10 P-13-546.2 4.13 6.91 0.00 6.91 0.00 778.41 6.76 0.00 6.76 0.00 778.34 6.54 0.00 6.54 0.00 778.26 5.79 0.00 5.79 0.00 778.13 3.90 0.00 3.90 0.00 777.87 1.97 0.00 1.97 0.00 776.76 1.54 0.00 1.54 0.00 775.90 10 P-13-547.1 0.73 2.74 0.00 2.74 28703.14 778.80 3.38 0.00 3.38 10877.01 778.61 3.25 0.00 3.25 973.46 778.24 3.09 0.00 3.09 0.00 778.05 2.42 0.00 2.42 0.00 777.72 2.16 0.00 2.16 0.00 776.85 1.62 0.00 1.62 0.00 776.05 10 P-13-547.2 0.73 2.74 0.00 2.74 0.00 778.80 3.38 0.00 3.38 0.00 778.61 3.25 0.00 3.25 0.00 778.24 3.09 0.00 3.09 0.00 778.05 2.42 0.00 2.42 0.00 777.72 2.16 0.00 2.16 0.00 776.85 1.62 0.00 1.62 0.00 776.05 10 P-13-548.1 1.99 3.75 13.91 17.66 3095.08 778.80 2.70 8.56 11.26 287.58 778.61 3.22 3.52 6.74 0.00 778.24 2.97 1.02 3.99 0.00 778.05 2.92 0.00 2.92 0.00 777.70 2.36 0.00 2.36 0.00 776.88 1.65 0.00 1.65 0.00 776.18 5 P-13-548.2 2.00 3.77 0.00 3.77 0.00 778.80 2.72 0.00 2.72 0.00 778.61 3.23 0.00 3.23 0.00 778.24 2.98 0.00 2.98 0.00 778.05 2.94 0.00 2.94 0.00 777.70 2.37 0.00 2.37 0.00 776.88 1.66 0.00 1.66 0.00 776.18 5 P-13-549.1 1.98 3.69 12.03 15.72 0.00 778.79 4.04 6.59 10.63 0.00 778.61 3.16 0.08 3.24 0.00 778.42 2.96 0.00 2.96 0.00 778.03 2.79 0.00 2.79 0.00 777.73 2.38 0.00 2.38 0.00 776.91 1.66 0.00 1.66 0.00 776.30 10 P-13-549.2 1.99 3.70 0.00 3.70 0.00 778.79 4.06 0.00 4.06 0.00 778.61 3.17 0.00 3.17 0.00 778.42 2.97 0.00 2.97 0.00 778.03 2.80 0.00 2.80 0.00 777.73 2.38 0.00 2.38 0.00 776.91 1.67 0.00 1.67 0.00 776.30 10 P-13-550.1 0.93 -2.93 51.24 54.17 0.00 779.51 -2.85 51.24 54.09 0.00 779.16 -2.59 51.24 53.83 0.00 778.64 2.38 51.24 53.62 0.00 778.03 2.23 51.24 53.47 0.00 777.63 1.82 51.24 53.06 0.00 776.85 0.99 51.24 52.23 0.00 776.52 <1 P-13-550.2 0.93 -2.92 0.00 2.92 0.00 779.51 -2.85 0.00 2.85 0.00 779.16 -2.59 0.00 2.59 0.00 778.64 2.38 0.00 2.38 0.00 778.03 2.23 0.00 2.23 0.00 777.63 1.82 0.00 1.82 0.00 776.85 0.99 0.00 0.99 0.00 776.52 <1 P-13-551.1 0.85 -2.28 0.00 2.28 21763.39 778.48 -2.17 0.00 2.17 16069.18 778.43 -2.83 0.00 2.83 10236.71 778.34 -1.99 0.00 1.99 5748.41 778.10 -1.79 0.00 1.79 153.26 777.94 -1.13 0.00 1.13 0.00 776.29 -0.14 0.00 0.14 0.00 775.52 2 P-13-551.2 1.55 3.34 0.00 3.34 0.00 778.48 3.25 0.00 3.25 0.00 778.43 3.22 0.00 3.22 0.00 778.34 2.43 0.00 2.43 0.00 778.10 2.94 0.00 2.94 0.00 777.94 1.14 0.00 1.14 0.00 776.29 0.15 0.00 0.15 0.00 773.90 >100 P-13-660 110.07 2.24 0.00 2.24 0.00 759.19 1.94 0.00 1.94 0.00 759.15 1.98 0.00 1.98 0.00 759.10 2.70 0.00 2.70 0.00 759.02 2.24 0.00 2.24 0.00 758.94 0.54 0.00 0.54 0.00 758.65 0.00 0.00 0.00 0.00 757.83 >100 P-13-764 22.29 49.30 0.00 49.30 547765.73 780.22 47.35 0.00 47.35 350107.76 780.12 46.74 0.00 46.74 186860.17 779.99 47.51 0.00 47.51 71698.94 779.74 47.77 0.00 47.77 10591.19 779.38 25.47 0.00 25.47 0.00 776.59 14.21 0.00 14.21 0.00 774.09 2 P-13-765.1 14.85 39.40 21.97 61.37 0.00 778.49 41.80 19.11 60.91 0.00 778.47 38.89 15.49 54.38 0.00 778.44 39.12 9.58 48.70 0.00 778.39 40.45 3.46 43.91 0.00 778.32 26.15 0.00 26.15 0.00 776.11 14.03 0.00 14.03 0.00 773.89 2 P-13-766.1 27.14 40.24 38.38 78.62 4532.17 777.75 42.54 38.21 80.75 1830.11 777.62 34.56 37.55 72.11 0.00 777.46 34.33 35.95 70.28 0.00 777.23 41.85 31.11 72.96 0.00 777.13 26.11 0.00 26.11 0.00 775.36 13.95 0.00 13.95 0.00 773.61 2 P-13-791.1 26.86 32.11 43.11 75.22 72476.95 777.71 32.63 40.55 73.18 39884.72 777.59 33.08 36.03 69.11 18998.75 777.43 33.04 30.11 63.15 7152.33 777.22 31.77 22.45 54.22 4737.41 777.12 26.05 0.00 26.05 0.00 775.15 13.90 0.00 13.90 0.00 773.52 2 P-13-792.1 16.31 47.20 56.54 103.74 0.00 777.65 48.09 49.00 97.09 0.00 777.52 49.99 39.80 89.79 0.00 777.35 46.30 24.13 70.43 0.00 777.14 42.78 9.60 52.38 0.00 777.02 34.40 0.00 34.40 0.00 774.83 18.51 0.00 18.51 0.00 773.40 2 P-13-793.1 30.47 50.91 57.11 108.02 4326.88 777.57 49.86 52.29 102.15 1326.53 777.43 47.42 46.38 93.80 0.00 777.19 46.25 26.33 72.58 0.00 776.79 44.48 0.12 44.60 0.00 776.46 34.25 0.00 34.25 0.00 774.43 18.41 0.00 18.41 0.00 773.25 2 P-13-794 31.40 63.15 0.00 63.15 27011.59 777.48 62.23 0.00 62.23 13336.66 777.33 60.20 0.00 60.20 3445.24 777.09 54.43 0.00 54.43 0.00 776.44 44.56 0.00 44.56 0.00 775.88 33.97 0.00 33.97 0.00 774.14 18.28 0.00 18.28 0.00 773.18 10 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® Page 3 of 3 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 3.02-4.doc\052506 TABLE 3.02-4 (CONTINUED) EXISTING PEAK CHARGES–ELEVATIONS SUMMARY Conduit Name Design Flow (cfs) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) Maximum Computed Pipe Flow (cfs) Overland Flow (cfs) Total Flow (cfs) Upstream Ponding Allowed (cft) Maximum Water Elevation (ft) pipe capacity 5 year 2 year 1year100year 50 year 25 year 10 year P-16-425.1 27.81 30.31 44.33 74.64 0.00 756.32 29.78 31.75 61.53 0.00 756.22 29.09 21.41 50.50 0.00 756.12 28.60 9.17 37.77 0.00 755.98 27.11 0.00 27.11 0.00 755.41 17.69 0.00 17.69 0.00 751.01 11.50 0.00 11.50 0.00 750.53 5 P-16-426.1 23.08 30.51 44.37 74.88 0.00 755.40 29.74 31.66 61.40 0.00 755.30 29.05 21.08 50.13 0.00 755.20 28.58 8.52 37.10 0.00 755.06 27.11 0.00 27.11 0.00 754.39 17.56 0.00 17.56 0.00 750.50 11.42 0.00 11.42 0.00 750.03 5 P-16-427.1 22.28 30.47 44.99 75.46 0.00 754.46 29.72 31.97 61.69 0.00 754.36 28.98 22.99 51.97 0.00 754.25 28.56 9.48 38.04 0.00 754.11 27.11 0.00 27.11 0.00 753.31 17.49 0.00 17.49 0.00 749.91 11.37 0.00 11.37 0.00 749.37 5 P-16-428.1 30.82 46.01 92.34 138.35 0.00 753.57 45.39 64.89 110.28 0.00 753.45 42.49 40.32 82.81 0.00 753.45 45.88 13.39 59.27 0.00 753.24 42.31 0.00 42.31 0.00 752.25 27.45 0.00 27.45 0.00 749.42 17.72 0.00 17.72 0.00 748.88 5 P-16-429.1 30.78 31.84 89.20 121.04 0.00 752.81 32.04 74.89 106.93 0.00 752.57 39.46 44.75 84.21 0.00 752.47 49.05 3.89 52.94 0.00 752.12 42.15 0.00 42.15 0.00 750.73 27.43 0.00 27.43 0.00 748.67 17.71 0.00 17.71 0.00 748.22 5 P-16-430 131.29 94.40 0.00 94.40 16883.84 752.78 86.04 0.00 86.04 15078.95 752.47 79.51 0.00 79.51 0.00 751.70 55.36 0.00 55.36 0.00 750.18 44.92 0.00 44.92 0.00 749.29 29.14 0.00 29.14 0.00 748.05 18.79 0.00 18.79 0.00 747.81 25 P-16-469.1 38.72 47.56 80.50 128.06 47002.26 752.93 45.19 65.23 110.42 18598.68 752.73 34.43 53.78 88.21 10511.07 752.62 42.79 28.81 71.60 2905.29 752.39 42.15 0.00 42.15 0.00 751.26 27.43 0.00 27.43 0.00 748.93 17.71 0.00 17.71 0.00 748.43 5 P-16-487 23.96 94.40 0.00 94.40 0.00 751.93 86.04 0.00 86.04 0.00 751.78 79.51 0.00 79.51 0.00 751.12 55.37 0.00 55.37 0.00 749.88 44.94 0.00 44.94 0.00 748.98 29.14 0.00 29.14 0.00 747.64 18.79 0.00 18.79 0.00 747.59 >100 P-16-495.1 23.20 32.58 43.41 75.99 0.00 755.70 32.05 30.58 62.63 0.00 755.60 30.65 20.00 50.65 0.00 755.51 29.44 7.50 36.94 0.00 755.37 27.11 0.00 27.11 0.00 754.70 17.63 0.00 17.63 0.00 750.65 11.46 0.00 11.46 0.00 750.16 5 P-16-646 131.11 134.42 0.00 134.42 0.00 757.39 120.36 0.00 120.36 0.00 756.99 103.33 0.00 103.33 0.00 755.45 78.93 0.00 78.93 0.00 753.37 62.64 0.00 62.64 0.00 752.44 37.45 0.00 37.45 0.00 751.74 17.06 0.00 17.06 0.00 751.08 >100 P-16-647 129.99 134.42 0.00 134.42 0.00 760.69 120.36 0.00 120.36 0.00 759.64 103.32 0.00 103.32 0.00 757.20 78.92 0.00 78.92 0.00 755.59 62.65 0.00 62.65 0.00 755.10 37.46 0.00 37.46 0.00 754.44 17.07 0.00 17.07 0.00 753.80 >100 P-40D-22 146.04 94.36 0.00 94.36 0.00 765.04 83.99 0.00 83.99 0.00 763.80 72.71 0.00 72.71 0.00 762.71 59.09 0.00 59.09 0.00 762.20 49.45 0.00 49.45 0.00 761.86 33.37 0.00 33.37 0.00 761.25 17.16 0.00 17.16 0.00 760.50 >100 P-AEW-1.1 43.90 41.89 55.83 97.72 0.00 757.65 41.22 47.46 88.68 0.00 757.59 40.81 40.27 81.08 0.00 757.52 39.63 32.57 72.20 0.00 757.42 38.27 26.16 64.43 0.00 757.33 36.26 9.64 45.90 0.00 757.13 28.62 0.00 28.62 0.00 755.83 1 P-AEW-1.2 43.94 41.9 0 93.58 0 757.651 41.22 0 41.22 0 757.586 40.82 0 40.82 0 757.523 39.63 0 39.63 0 757.422 38.27 0 38.27 0 757.332 36.29 0 36.29 0 757.126 28.62 0 28.62 0 755.828 1 P-AEW-10 110.32 51.68 0 166.01 0 766.02 50.36 0 50.36 0 765.685 48.8 0 48.8 0 765.447 47.65 0 47.65 0 765.19 44.16 0 44.16 0 764.984 33.81 0 33.81 0 764.578 20.81 0 20.81 0 764.005 >100 P-AEW-13 129.88 114.33 0 149.61 0 763.915 105.09 0 105.09 0 762.623 74.98 0 74.98 0 760.618 59.58 0 59.58 0 759.961 49.68 0 49.68 0 759.553 33.53 0 33.53 0 758.928 17.1 0 17.1 0 758.336 >100 P-AEW-14 122.94 35.28 0 77.75 4207.31 779.451 36.7 0 36.7 1875.74 779.337 37.26 0 37.26 193.79 779.179 36.9 0 36.9 0 778.784 35.53 0 35.53 0 778.427 30.46 0 30.46 0 777.803 24.67 0 24.67 0 777.329 10 P-AEW-15 34.18 42.47 0 54.56 228103.96 779.439 41.93 0 41.93 129054.77 779.325 41.16 0 41.16 57656.09 779.166 39.23 0 39.23 7171.01 778.771 37.44 0 37.44 221.7 778.413 32.17 0 32.17 0 777.787 25.58 0 25.58 0 777.304 2 P-AEW-16 31.82 12.09 0 117.04 0 763.569 -8.81 0 8.81 0 762.571 -7.64 0 7.64 0 762.023 -4.45 0 4.45 0 761.095 -2.11 0 2.11 0 760.571 -0.06 0 0.06 0 760.273 0 0 0 0 760.27 >100 P-AEW-3.1 137.35 104.95 3.47 214.75 0 769.722 101.66 0 101.66 0 769.576 94.25 0 94.25 0 769.302 80.84 0 80.84 0 768.811 67.01 0 67.01 0 767.944 49.69 0 49.69 0 766.712 34.54 0 34.54 0 766.012 50 P-AEW-8 67.86 109.8 0 117.42 0 773.964 108.77 0 108.77 0 773.895 106.94 0 106.94 0 773.8 101.13 0 101.13 0 773.556 92.15 0 92.15 0 773.128 71.04 0 71.04 0 772.276 40.64 0 40.64 0 771.189 >100 P-AP-1 3.54 7.62 0 53.82 0 769.487 5.93 0 5.93 0 768.836 4.23 0 4.23 0 768.332 2.76 0 2.76 0 767.778 2.67 0 2.67 0 767.375 1.88 0 1.88 0 766.848 1.11 0 1.11 0 766.432 >100 P-LP-1 38.75 46.2 0 209.92 22996.97 764.552 47.76 0 47.76 10835.59 764.404 47.8 0 47.8 6471.42 764.31 47.06 0 47.06 3904.64 764.22 44.08 0 44.08 341.35 763.995 33.78 0 33.78 0 763.208 20.78 0 20.78 0 762.519 2 P-STR-10 11.9 35.05 0 70.11 1379956.63 781.043 36.61 0 36.61 890696.36 780.95 37.25 0 37.25 508544.36 780.826 36.9 0 36.9 209544.59 780.611 35.51 0 35.51 73262.55 780.306 30.43 0 30.43 0 779.297 24.66 0 24.66 0 778.342 2 P-STR-5 12.19 35.06 0 37.19 0 780.215 36.62 0 36.62 0 780.111 37.25 0 37.25 0 779.968 36.9 0 36.9 0 779.648 35.51 0 35.51 0 779.319 30.43 0 30.43 0 778.522 24.66 0 24.66 0 777.823 >100 p-WM MH-1 1.55 2.13 0 4.33 0 767.1 2.23 0 2.23 0 766.537 2.23 0 2.23 0 766.13 2.25 0 2.25 0 765.711 2.09 0 2.09 0 765.281 1.58 0 1.58 0 764.748 1.42 0 1.42 0 764.423 >100 P-WM P-1 0.99 2.2 0 7.46 0 768.39 2.22 0 2.22 0 767.724 2.22 0 2.22 0 767.197 2.24 0 2.24 0 766.742 2.08 0 2.08 0 766.157 1.6 0 1.6 0 765.359 1.42 0 1.42 0 765.072 >100 P-WM P-2 4.33 5.26 0 5.26 0 768.39 3.22 0 3.22 0 767.724 -3.51 0 3.51 0 767.197 -3.96 0 3.96 0 766.742 -3.46 0 3.46 0 766.251 -2.19 0 2.19 0 766.09 -2.97 0 2.97 0 766.195 >100 EXISTING CONDITIONS DIVERSION ANALYSIS NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE3.02-31-382.021 Diversion PT 3 30" RCP IE = 760.27 Diversion PT 2 3' x 4.5' RCP Box IE = 762.54 Diversion PT 1 High PT = 776.35 42" RCP IE = 775.25 S:\@SAI\351--400\382\021\GIS\Report Figures\Existing Conditions Diversion Analysis.mxd 0 500 1,000 250 Feet Legend Drainage Basin Boundary Sub Drainage Basin Boundary Landmark Plaza Storm Manhole Storm Sewer Water Valve Water Main Sanitary Manhole Sanitary Sewer Diversion Point Flow (CFS) Q1 = 17 Q2 = 33 Q5 = 50 Q10 = 60 Q25 = 75 Q50 = 102 Q100 = 114 Q6/11/04 = 93 Flow (CFS) Q1 = 16 Q2 = 31 Q5 = 46 Q10 = 55 Q25 = 66 Q50 = 76 Q100 = 80 Q6/11/04 = 79 Flow (CFS) Q1 = 34 Q2 = 68 Q5 = 103 Q10 = 111 Q25 = 115 Q50 = 117 Q100 = 119 Q6/11/04 = 116 Flow (CFS) Q1 = 25 Q2 = 30 Q5 = 36 Q10 = 37 Q25 = 37 Q50 = 37 Q100 = 35 Q6/11/04 = 37 Flow (CFS) Q1 = 21 Q2 = 34 Q5 = 44 Q10 = 47 Q25 = 48 Q50 = 49 Q100 = 52 Q6/11/04 = 51 Flow (CFS) Q1 = 0 Q2 = 0 Q5 = 0 Q10 = 0 Q25 = 0 Q50 = 0 Q100 = 13 Q6/11/04 = 0 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 3–Engineering Analysis Prepared by Strand Associates, Inc.® 3-7 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S3.doc\052506 Creek and thus away from the Landmark Plaza at Diversion Point 2 appears feasible only if the storm sewer leading from just north of Witzel Avenue to the Sawyer Creek/Washburn Street outfall is upsized to maintain the existing 100-year capacity of that segment of storm sewer. Diversion of additional flow to the east to reduce flooding along Washburn Street at Diversion Point 1 appears to be feasible, provided it is routed to the proposed Armory detention pond. 6. The capacity of the existing ditch and connecting storm sewer culvert through Landmark Plaza are currently limited by backwater caused by the downstream drainage system. The western four ditch segments through Landmark Plaza currently have a 2-year, 2- hour duration capacity. The easternmost ditch segment has a 5-year, 2-hour duration capacity. The existing storm sewer culvert along the ditch currently has a 2-year, 2-hour duration capacity. In general, if the downstream “bottleneck” and associated backwater are reduced/relieved, modeling results indicate that these ditch segments and connecting storm sewer culvert appear to be able to pass the 100-year, 2-hour duration storm event flows around the west and south sides of the southern Landmark Plaza building and the movie theater building without inundating these buildings. 7. The Landmark Plaza internal drainage in the areas west and southwest of the eastern Landmark Plaza building (modeled nodes 06-846, 06-847, and 06-1293.2) have adequate overland flow routes that would convey flows around the building rather than flood the building if the downstream drainage system capacity is increased. If each of these nodes were to be clogged with debris so that the inlets were not accepting flow, the 100-year, 2-hour duration storm event would be passed around the north and south sides of the building at a maximum elevation of 761.95 (761.55 north side, 761.60 middle, and 761.95 south side), which is 0.33 feet (4 inches) lower than the first floor elevation of the eastern Landmark Plaza building if downstream drainage system capacity is increased. However, node 06-846 would have to pond to 12.8 inches, node 06-847 would have to pond to 15.5 inches, and node 06-1293.2 would have to pond to 11.8 inches before overflowing along these routes. We would normally recommend no more than 6 to 9 inches of ponding to avoid damage to vehicles at low points. In summary, if the downstream backwater effects are alleviated, these three nodes appear to have adequate overland flow routes to the east and southeast sides of the eastern Landmark Plaza building. If the downstream backwater effects are not alleviated, then flooding similar to the June 10/11, 2004, storm event in larger storm events will continue. We recommend that the owner of the Landmark Plaza perform a study to determine how to reduce potential ponding at the three stormwater inlets (nodes 06-846, 06,847, and 06-1293.2) to an acceptable level considering that downstream backwater effects are alleviated. See Figure 3.02-2 for node locations. SECTION 4 ALTERNATIVE ANALYSIS City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-1 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Available (acre-feet) Armory 2.7 Westhaven Golf Course 8.1 Wal-Mart 6.9 Entire Watershed Flooding (Storage Deficit/Need)– Existing Conditions ----- Entire Watershed Flooding (Storage Deficit/Need)– Future Conditions ------ Total Existing Detention 17.7 Table 4.01-1 Existing Available Detention Alternative 1–Components (Potential Detention Sites) Potential Available Storage (acre-feet) 1a–Detention at Vacant Lot South of Landmark Plaza (Wet Pond) 6.20 1b–Detention at Golf Course (Wet Pond)–Potential Additional w/Pond Modification 8.8** 1c–Detention at Vacant Lot Southwest of 9th Avenue/Washburn Street Intersection (Wet Pond) 35.5 1d–Detention at Tippler Junior High (Dry Pond) 16.2** 1e–Armory Detention and USH 41 Pipe Upsizing (Wet Pond) 53.2 Expanded Westhaven Golf Course Detention (Wet Pond) 130 Expanded Tippler Junior High (Dry/Wet Pond) 41.5 TOTAL 266.4 ** Available Storage at elevation just prior to use of pond overflow. Alternatives 1b and 1d are not included in total because expansion of these facilities provides more potential detention Table 4.01-2 Proposed Alternatives Detention Availability–Future Conditions 4.01 GENERAL A. Alternatives Analysis Overview This section discusses alternatives analyzed to address existing flooding at Landmark Plaza, based on discussions between City and Strand Associates staff. Each alternative includes a description, the effects on flooding at Landmark Plaza, the effects on flooding watershed-wide, and the planning-level Opinion of Probable Cost. Costs presented were estimated using historical bid costs, where available, and supplemented by other reference sources. All estimated project costs include allowances for engineering and contingencies, soils investigation where necessary, and land acquisition costs. The goal of this report is to provide City personnel with the information required to initiate the budgeting and planning phase for facilities improvements. All costs are presented in 2nd quarter 2006 dollars. Future construction costs should be adjusted for inflation when final project schedules are determined. Opinions of probable construction cost estimates will be updated during the design phase. B. Existing Detention in Watershed Each alternative model includes existing detention at the Armory, Westhaven Golf Course, and Wal- Mart. The available detention at each of these existing facilities is included in Table 4.01-1. Table 4.01-2 shows the potential amount of storage available for the alternatives being considered. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 C. Overview of Alternatives Evaluated The following alternatives were analyzed: 1. Alternative 1–Additional detention consisting of the following components: a. Detention at vacant parcel south of the Landmark Plaza. b. Additional detention at the golf course, if feasible. c. WisDOT Right-of-Way (ROW) detention–The City has indicated this is not feasible through discussions with the DOT. In its place, we have analyzed additional detention southwest of the W. 9th Avenue and Washburn Street Intersection in vacant land. d. Detention at Tippler Junior High property. e. Detention at the Armory site including upstream pipe upsizing (diversion modification) to feed the basin. 2. Alternative 2–Increase Conveyance Capacity in North Branch System including the following components: a. Additional internal capacity at Landmark Plaza. b. Expansion of ditch south of Landmark Plaza, if necessary. c. Downstream pipe upsizing to convey the 100-year flow. 3. Alternative 3–Diversion Modification–This alternative analyzes a potential reduction in capacity of Diversion Point 2 that would reduce the flowrate entering Landmark Plaza and increase the flowrate going north toward Sawyer Creek. 4. Alternative 4–Stormwater Pump Station at Downstream End of Campbell Creek. 5. Alternative 5–Analysis of Single-Mix of Above Components including the following components: a. Detention at vacant parcel south of the Landmark Plaza. b. Detention at Tippler Junior High property. c. Detention at the Armory site and upstream pipe upsizing to feed the basin. 6. Alternative 6 through 11–The components of these alternatives are shown in Table 4.01-3. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-3 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Alternative 1 2 3 4 5 6 7 8 9 10 11 Detention at Tippler Junior High Yes No No No Yes No No No No No No Expanded Detention at Tippler Junior High No No Yes No No Yes Yes Yes Yes Yes Yes Larger Pipe from Landmark Plaza to Tippler No Yes Yes No No Yes Yes Yes Yes Yes Yes Detention South of Landmark Plaza Yes No No No Yes No No No No No No Existing Detention at Armory No Yes No Yes No No No No No No No Expanded Detention at Armory Yes No Yes No Yes Yes Yes Yes Yes Yes Yes Detention at 9th Avenue/Washburn Street Yes No Yes No No Yes Yes Yes Yes No No Existing Golf Course Detention Yes Yes No Yes Yes Yes Yes No No No No Expanded Golf Course Detention No No Yes No No No No Yes Yes Yes Yes Pump Station at Campbell Creek Outfall No No No Yes No No No No No No No Diversion Pipe under HWY 41 at Landmark Plaza Yes Yes Yes Yes Yes No Yes No Yes No Yes 100-year storm sewer in WisDOT ROW from Landmark Plaza Diversion to Sawyer Creek along USH 41 No No Yes No No Yes No Yes No Yes No Existing Wal-Mart Detention Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Increase Conveyance Capacity from Landmark Plaza to Campbell Creek Outfall No Yes No No No No No No No No No Increase Internal Conveyance Capacity at Landmark Plaza No Yes No No No No No No No No No Modified Diversion Pipe under HWY 41 at Landmark Plaza No No Yes No No No No No No No No Table 4.01-3 Alternative Components D. Alternative Goals In assessing/ranking each Alternative, we have focused on not only alleviating flooding in the Landmark Plaza area but also have assessed each alternative in terms of the watershed-wide benefit. The goals of the alternatives are the following. In Sections 4.02 to 4.12, the benefits of each option are stated in terms of freeboard and flooding at Landmark Plaza (analyzed at the low point on the east side of the eastern Landmark Plaza building) and meeting of Landmark Plaza freeboard criteria for the 10-year, 2-hour and 12-hour duration, 100-year, 2-hour and 12-hour duration, and June 10/11, 2004, storm events. They are also ranked in terms of Landmark Plaza benefit, watershed-wide benefit, and an average of these two rankings as the overall average ranking. The ranking data and criteria used for these rankings are included in Table 4.13-2 and 4.13-3. 1. Landmark Plaza a. Provide a minimum of 1.5 feet of freeboard from the computed high water elevation in the Landmark Plaza Basin to the elevation of the 1st floor elevation (762.28) of the eastern Landmark Plaza Building with 2 feet of freeboard being desirable for the 100-year storm of critical duration. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-4 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 b. Provide a minimum of 1.5 feet of freeboard from the computed high water elevation in the Tippler Junior High Basin to the elevation of the 1st floor elevation (761.31) of the Tippler Junior High northern building with 2 feet of freeboard being desirable for the 100-year storm of either 2-hour or 12-hour duration (whichever controls by causing a higher elevation at the Tippler Basin). c. Reduce the number of locations and occurrence frequency of pipe and ditch overflows in the Landmark Plaza Basin. d. Treat areas without defined floodplains in a similar manner as defined floodplains (per FEMA maps) so that certain provisions of NR 116- Wisconsin’s Floodplain Management Program would apply. NR 116 calls for new structures to be built at or above the flood protection elevation. The flood protection elevation means an elevation 2 feet above the regional flood elevation or calculated 100-year elevation adjacent to a structure. The 2 feet of freeboard is a safety factor that compensates for the effects of many factors that contribute to flood heights greater than those calculated (debris accumulation, effects of urbanization, and loss of flood storage because of development, among others defined in NR 116). NR 116 can be found on-line at: http://www.legis.state.wi.us/rsb/code/nr/nr116.pdf. Many times in retrofit situations, a lesser freeboard of 1.5 feet is considered acceptable in recognition of the fact that it may not be cost-effective to provide the full 2 feet of freeboard. Based on these guidelines, Alternatives 1, 4, and 5 were eliminated from consideration because they provide less than 1.5 feet of freeboard at Landmark Plaza and Tippler Junior High. Alternative 2 provides 1.5 to 2 feet of freeboard at both Landmark Plaza and Tippler Junior High Alternatives 3, 6, 7, 8, 9, 10, and 11 all provide greater than 2 feet of freeboard at these two locations. 2. Watershed-Wide a. Reduce the amount of flooding in the watershed for the 1- through 100-year storm events under existing and future conditions and for the June 10 and 11, 2004, storm event. b. Reduce the amount of flooding occurring in the 10-year storm event under existing and future conditions by reducing flows through as many existing storm sewers as possible to less than a 10-year storm event with the Alternatives considered. c. Maximize the use of detention considered with these alternatives to provide opportunities for TSS reductions along with peak flow reductions. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-5 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 d. Reduce the peak discharge rates to the USH 41/Sawyer Creek, Westfield Drive/Sawyer Creek, and Campbell Creek outfalls to the maximum extent practicable with the Alternatives considered. e. Keep the increase in flows to the USH 41/Sawyer Creek outfall as small as possible. This is in recognition that Alternatives 3, 6, 8, and 10 include increasing the size of the existing storm sewer leading from USH 41/Sawyer Creek to just north of Witzel Avenue (Options 6, 8, and 10 also increase the pipe size under Witzel) to keep the ditch and storm sewer combination from the Landmark Plaza diversion point to the USH 41/Sawyer Creek outfall at a 100-year capacity under future conditions. The reason for this is that there are already downstream flooding problems in the area of the Westfield Drive/Sawyer Creek outfall. If the City chooses an option that upsizes this storm sewer, it is recommended that the Sawyer Creek watershed upstream of this point be provided with detention that will offset the difference between the future conditions 100-year flow rate (with upsized storm sewer contemplated under this study) and the existing conditions 100-year flow rate (approximately 134 cfs for 2-hour duration and 153 for 12-hour duration). 4.02 ALTERNATIVE 1–DETENTION AT FOUR LOCATIONS To reduce flooding in the Landmark Plaza and in downstream areas, we have analyzed the addition of detention at four locations. Alternative 1 is a combination of all the detention in Component 1a through 1e, excluding Component 1b as discussed below. Each of these components is described below with an individual cost for each component. Component 1a–Detention at Vacant Parcel South of Landmark Plaza We have analyzed the addition of detention at the vacant parcel south of Landmark Plaza. This vacant parcel is about 2.63 acres. This lot could conceivably provide about 6.2 acre-feet of storage assuming layout as a wet pond as shown in Figure 4.02-1a. This parcel currently drains northeasterly to the drainage ditch on the south end of the Landmark Plaza. Component 1b–Additional Golf Course Detention The Westhaven Golf Club currently has an area that serves as a stormwater detention pond. The pond as it exists today provides approximately 8.1 acre-feet of detention before overtopping to the east. To reduce downstream flooding, we have looked at increasing the detention capacity of the existing facility. The pond currently reaches an elevation of about 780 feet covering an area of about 7.77 acres. Our analysis considers increasing the detention volume by constructing a berm at the eastern edge of the property that would allow ponding to an elevation of about 781 feet covering an area of about 9.8 acres, thus providing a total of 16.9 acre-feet of storage (8.8 acre-feet additional). This option is shown in Figure 4.02-1b. As can be seen in Figure 4.02-1b, this would inundate a much larger area (approximately 2 more acres) of the golf course in large events than currently occurs. Another option City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-6 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Parcel Number Area 91311840100 1.772 acres 91311870100 (existing home at north end) 1.997 acres 91311860000 4.621 acres 91311860100 3.830 acres Total 12.22 acres Table 4.02-1 Vacant Parcel Information–Component 1c here may be to lower the normal water surface elevation by 1.46 feet to provide an additional 1.4 acre- feet. Because of the negative consequences of further golf course inundation and the minimal benefit of the lowering of the water surface, this expansion is probably not feasible. The model has thus not considered modification to the existing golf course detention under this alternative. Component 1c–Additional Detention in Vacant Land Southwest of W. 9th Avenue/Washburn Street Intersection We have analyzed the addition of detention at the vacant parcel southwest of the W. 9th Avenue/Washburn Street intersection. This area is actually four parcels. A house is currently located on one of these parcels. As shown in Table 4.02-1, the total area of these four parcels is 12.22 acres. Of this total, about 10.76 acres (504 feet x 930 feet) appears to be feasible for the footprint of a detention basin. This 10.76-acre area could conceivably provide about 35.5 acre-feet of storage assuming a wet pond configuration as shown in Figure 4.02-1c. The layout shown provides for an aesthetically pleasing edge as well as an island to benefit wildlife habitat. This parcel currently appears to drain easterly toward Washburn Street. This option is shown in Figure 4.02-1c. The cost shown for this component in Figure 4.02-2 is the cost for a basin approximately 15- percent larger than that shown in Figure 4.02-1C to allow for maximizing the use of the parcel for stormwater storage. Component 1d–Detention at Tippler Junior High Pr operty To provide flooding relief directly to the Landmark Plaza as well as to downstream areas, we have analyzed the addition of detention at Tippler Junior High. Being on school district property, it appears feasible to construct a dry detention basin that would be used for detention during large rain events and as athletic fields when it is not raining. Approximately the 2-year flow would be allowed to bypass the detention but larger storms would divert into this detention system. The area that appears available for this type of system is an approximate 5.5-acre open area (490 feet x 490 feet) in the north one-half of this property. This 5.5-acre area could conceivably provide about 16.5 acre-feet of storage assuming a dry pond configuration as shown in Figure 4.02-1d. This parcel currently appears to be somewhat of a depressional area that overflows to the east once reaching approximately elevation 758.70 according to our field survey information. This option is shown in Figure 4.02-1d. Component 1e–Detention at the Armory Site and Upstream Pipe Upsizing to Feed the Basin This component was originally proposed in the December 1994 Stormwater Management study. The 1994 study recommended this basin be sized to store 40 acre-feet for the 10-year storm and 85 acre-feet for the 100-year storm. The wet detention basin shown in Figure 4.02-1e can hold about 53 acre-feet during the 100-year storm. To fully utilize this detention, upgrading of the ALTERNATIVE 1 - COMPONENT 1A DETENTION AT VACANT LOT SOUTH OF LANDMARK PLAZA NORTH BRANCH CAMPBELL CREE K STORMWATER STUD Y CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.02-1A1-382.021 WSEL = 760 IE = 760.0 IE = 760.0 IE = 759.78 75' - 18" RCP@ 0.3% Existing Ditch 222' - 34" x 53" HERCP@ 0.43% 100 - Year EmergencySpillway L = 20' Construct DiversionManhole With ConcreteWeirwall at Elev. = 767.6 N KOELLER ST S WASHBURN ST W 5TH AVE US HWY 41 ON RAMPUS HWY 41 RAMP US HWY 41 NORTHBOUND LILAC ST US HWY 41 SOUTHBOUND W 5TH AVE 768 764 762 770 772 774 0 766 766 766 0 764 764 0 764 0 768 764 770 770 768 766 764 0 768 768 770 770 768 772 0 762 762 770 768 768 0 766 24 0 3654 21 15 18 30 2945 6540 12 15 12 21 18 18 15 12 21 12 30 12 15 2945 15 12 12 24 24 2945 12 21 12 12 15 12 12 12 12 15 12 12 12 15 S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative 1a.mxd 0 100 20050 Feet Legend Storm Manhole Storm Sewer Water Valve Water Main Sanitary Manhole Sanitary Sewer Parcel Contour (2 FT.) Proposed Detention Proposed Pipe ALTERNATIVE 1 - COMPONENT 1B DETENTION AT GOLF COURSE NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.02-1B1-382.021 Provide Swale for Drainage Behind Berm Top of Berm Elev. = 781.0 Top of Berm Elev. = 781.0 SBB-60 SCB-85 SCB-75 SCB-70 SCB-80 MARICOPA DRGREENFIELD TR COVINGTON DR CUMBERLAND TR HERITAGE TR VILLA PARK DR THORNTON DR 782 780 784 778 786 776 788 780 780 786 782 780 778 782 780 782 778 780 786 778 778 782 786 786 782 780 786 784 780 782 786 782 784 782 784 784 784 782 786778 782 788 778 780 780 784 780 784 784 784 784 780 782 784 782 784 780 782 784 786 786 782 786 784 778 782 782 778 782 786 780 780 786 786 782 782 786 780 780 784 782 782 782 780 780 780 778 782 782 784 778 782 784 780780 778 782 778 786 42 6 12 24 27 15 5031 21 5836 18 2516 10 830 27 27 27 12 15 27 12 18 5031 2516 12 27 42 12 8 18 27 15 21 18 21 42 2516 18 5031 15 30 27 30 30 30 21 5031 8 15 2516 18 10 27 S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative 1b.mxd 0 160 320 80 Feet Legen d Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) Proposed Detention Proposed Pipe ALTERNATIVE 1 - COMPONENT 1C DETENTION AT VACANT LOT SOUTHEAST OF 9TH/WASHBURN STREET INTERSECTION NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.02-1C1-382.021 WSEL = 771.0 Top of Water Feature Elevation = 777.0 120' - 24" RCP @ 0.09% 238' - 18" RCP @ 0.86% 315' - 42" RCP @ 0.16% Construct New Manhole IE = 771.0 IE = 771.0 IE = 771.0 Construct New Manhole Over Existing Pipe IE = 771.49 Bulkhead Existing 42" Storm sewer to East Extra Inlets to Accept 100-YR Flow Extra Inlets to Accept 100-YR Flow FOREBAY FOREBAY 132' - 24" RCP @ 0.09% 175' - 24" RCP @ 0.09% Construct New Manhole IE = 770.62 MARICOPA DR CUMBERLAND TR S WASHBURN ST DICKINSON AVE ARDMORE TR 778 780 776 782 774 776 778 776 780 780 778 782 782 782 778 778776 778 782 780 780 778 782 778 780 778 780 778 780 778 780 782 780 778 780 780 780 778 780 780 780 780 776 778 776 782 42 24 6 27 15 12 18 0 2516 8 30 0 12 42 12 12 42 18 42 12 12 12 15 12 12 42 18 2516 S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative 1c.mxd 0 120 240 60 Feet Legend Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) Proposed Detention Proposed Pipe ALTERNATIVE 1 - COMPONENT 1D 100-YEAR OVERFLOW TO AND DETENTION AT TIPPLER JUNIOR HIGH NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.02-1D1-382.021 Proposed Manhole IE = 753.63 50' - 18" RCP @ 0.2% 400' - 18" RCP @ 0.2% Proposed Manhole IE = 752.83 Proposed Manhole IE = 752.38 Proposed Manhole IE = 751.99 Connect to Existing Manhole IE = 751.93 Connect to Existing Manhole IE = 752.56 82' - 18" RCP @ 0.2%425' - 18" RCP @ 0.2% 35' - 18" RCP @ 0.2% 88' - 18" RCP @ 0.2%30' - 18" RCP @ 0.2% 49' - 30" RCP @ 0.2% IE = 753.73 IE = 752.99 IE = 752.95 IE = 752.17 IE = 752.66 754 754 755 753 753 753 WITZEL AVE S WESTFIELD ST 762 764 760 766 758 764 764 764 760 762 762 764 764 764 764 764 762 764 766 21 24 5131 5836 27 18 5836 5836 27 5836 S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative 1d.mxd 0 100 200 50 Feet Legend Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) Proposed Detention Proposed Pipe ALTERNATIVE 1 - COMPONENT 1E NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.02-1E1-382.021 IE = 765.0 IE = 765.0 IE = 764.88 Normal WSEL = 765.0 60 LF - 30" RCP@ 0.2% Existing Ditch Top of BermElev. = 771.0 Place Steel PlateW/ 2' DIA. Orificeon Downstream Pipe(IE = 768.69) 110' - 5' DIA. RCP@ 4.3%Future Road ROWFuture Road ROW Existing Armory Drainage000Existing Armory DrainageExisting Armory Drainage Upgrade Storm Sewerto 38" x 60" HERCPTotal Length = 1021 LF IE = 769.69 42" S KOELLER ST S WASHBURN ST US HWY 41 SOUTHBOUND US HWY 41 NORTHBOUND MORELAND ST CRYSTAL SPRINGS AVE OSBORN AVE US HWY 41 RAMP MENARD DR ARMORY PL DICKINSON AVE WINDSOR ST REICHOW ST S WESTFIELD ST 776 778 774 772 770 780 768 762 760 758 756 754 752 750 742782 702 700 698 766 696784786 774 778 774 778 774 776 778 776 778 774 776 778 774 778 778 780 772 780 776 778 780 778 776 776 780 778 778 780 776 766 778 776 776 774 774 776 776 776 774 778 774 776 778 784 782 780 774 786 774 780 776 776 778 772 780 778 776 780 768 778 774 778 776 776 778 778 778 780 776 776 778 774 780 778 778 774 778 778776 768 24 4815 4212 27 18 0 2438 2516 8 12 42 12 12 42 24 24 12 24 24 12 12 24 12 12 42 12 12 24 12 12 15 15 48 12 24 24 12 12 15 15 24 12 27 42 12 12 12 12 12 S:\@SAI\351--400\382\021\GIS\Report Figures\South Branch Detention 1A.mxd 0 200 400100 Feet Legend Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) Proposed Detention Proposed Pipe City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-7 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 upstream storm sewer system extending to the west side of USH 41 is necessary and is referred to as a diversion modification. Because of the existing ditch to the north side of this basin, we have modeled the basin at the influent to the pond with a diversion structure that would allow flow to split either into a 24-inch orifice and continue through the ditch or through a 5-foot-diameter pipe to the pond. This is recommended to keep base flow in the ditch and provide for aquatic and terrestrial habitat in and along the ditch. This pond is situated in an area that has been officially mapped by the City of Oshkosh as a regional stormwater detention facility. By agreement with the State of Wisconsin, there would be no associated land acquisition costs associated with the eastern portion of the pond that is located on the Armory property. However, the western portion of the property is located on private lands and would require acquisition of approximately 5 acres of land. There is also a large mound of earthen material currently on the western portion of the site. We recommend that the City survey the mound and add the cost of its removal to the costs we provide below. If the DNR determines that the ditch to the north of the proposed Armory Pond is nonnavigable, this pond could possibly be expanded to become an on-line pond extending all the way to the north property line. If the DNR deems the ditch to be nonnavigable and the City would like to pursue this, a berm would need to be constructed along the north property line and a means to drain the back yards of the homes to the northeast would need to be designed. The Opinion of Probable Costs for the improvements outlined above is shown in Table 4.02-2. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-8 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Component 1a–Detention at Vacant Parcel South of Landmark Plaza Excavation $140,000 Riprap 1,500 Piping and Structures 42,000 Erosion Control 2,600 Landscaping/Restoration 37,200 Subtotal $ 223,300 Engineering and Contingencies (25%) 55,800 Subtotal $ 279,100 Soils Investigation 3,000 Land Acquisition (2.63 acres[114,835 sf] @ $10/sf) $1,148,300 Total $1,430,400 Component 1b–Additional Golf Course Detention Not Feasible Component 1c–Additional Detention in Vacant Land Southwest of 9th Street/Washburn Street Intersection Excavation $1,006,300 Riprap $ 2,400 Piping and Structures 88,900 Erosion Control 7,400 Landscaping/Restoration 171,100 Subtotal $ 1,276,100 Engineering and Contingencies (25%) 319,000 Subtotal $ 1,595,100 Soils Investigation 2,000 Land Acquisition (10.76 acres @ $20,000/acre) $215,200 Total $1,812,300 Component 1d–Detention at Tippler Junior High property Excavation $282,100 Riprap $ 3,700 Piping and Structures 65,500 Erosion Control 3,600 Landscaping/Restoration 104,900 Subtotal $ 459,800 Engineering and Contingencies (25%) 115,000 Subtotal $ 574,800 Soils Investigation 2,000 Land Acquisition (5.75 acres @ $20,000/acre) $115,000 Total $691,800 Component 1e–Detention at the Armory site and upstream pipe upsizing to feed the basin. (Costs do not include removal of existing large earthen mound) Excavation $1,348,600 Riprap $ 1,500 Piping and Structures 36,500 Erosion Control 6,000 Landscaping/Restoration 246,400 Upstream Pipe Upsizing and Manholes 194,200 Subtotal $ 1,833,200 Engineering and Contingencies (25%) 458,300 Subtotal $2,291,500 Soils Investigation 3,000 Land Acquisition (5 acres @ $5.35/square foot) $1,165,200 Total $3,459,700 Grand Total $7,394,200 Note: Cost do not include utility conflict resolution, if any. Table 4.02-2 Alternative 1–Opinion of Probable Cost–Detention at Four Locations City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-9 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre- feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 1.95 0.16 N/A 10-year, 12-hour w/alternative 2.12 0.09 N/A 100-year, 2-hour w/alternative 0.57 5.28 No 100-year, 12-hour w/alternative -0.04 10.45 No June 11, 2004 w/alternative (Existing Conditions) 0.36 7.17 N/A Average = 8 9 8 Table 4.02-3 Detention at Four Locations Effects–Future Conditions–Alternative 1 The overall effect of Alternative 1 is included in Table 4.02-3. Modeling results indicate the eastern Landmark Plaza building would flood about 0.04 feet (one-half inch) during the 100-year, 12-hour storm event and there would be substantial flooding in the Landmark Basin. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been reduced by roughly 56 percent (16.56 acre-feet down to 7.17 acre-feet), and the eastern Landmark Plaza building would not have flooded (0.36 feet of freeboard). However, this alternative does not meet the freeboard criteria at Landmark Plaza of a minimum of 1.5 feet of freeboard with 2.0 feet being desirable. In summary, modeling of Alternative 1 indicates that provision for detention at these locations alone is not sufficient to alleviate flooding at Landmark Plaza in conformance with the plan goals. However, the addition of detention to the watershed will have additional major benefit in other areas including streets and low points that currently flood. 4.03 ALTERNATIVE 2–INCREASE CONVEYANCE CAPACITY IN NORTH BRANCH SYSTEM To reduce flooding at the Landmark Plaza and downstream areas, we have looked at increasing the conveyance capacity of the Landmark Plaza internal system, expansion of the ditch south of Landmark Plaza, and upsizing of the downstream system. This alternative is shown in Figure 4.03-1. Component 2a–Additional Internal Capacity at Landmark Plaza To more efficiently drain the interior of Landmark Plaza, we recommend upgrading the storm sewer system to convey a 10-year design storm. Currently, once the existing pipe capacities at Landmark Plaza are exceeded, it appears the overflows pond on-site at low points prior to overflowing around the north and south sides of the eastern Landmark Plaza building to low areas on the eastern and southeastern sides of the Landmark Plaza property as described in Section 3.02 C. 7. During large rain events, ponding occurs on much of the Landmark Plaza property under existing conditions. This option is shown in Figure 4.03-2a. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-10 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Component 2b–Expansion of Ditch South of Landmark Plaza The capacity of the existing ditch and connecting storm sewer culvert through Landmark Plaza are currently limited by backwater caused by the downstream drainage system. As described in Section 3.02 C. 6., the western four ditch segments through Landmark Plaza currently have a 2-year, 2-hour duration capacity. The easternmost ditch segment has a 5-year, 2-hour duration capacity. The existing storm sewer culvert (P-LP-1) along the ditch currently has a 2-year, 2-hour duration capacity. Section 3.02 C. 6 indicates that upsizing of the downstream storm sewer system to the Campbell Creek outfall would increase the entire ditch to greater than a 10-year capacity. In addition, all but two of the five ditch segments would have 100-year capacity as a result of the reduction in downstream backwater effects from implementation of this alternative. Also, in this alternative, the existing culvert named P-LP- 1 (31-inch x 51-inch HERCP) that joins ditch D-AEW-11 to ditch D-LP-2 has greater than 10-year capacity with modeling showing minor overflows of this culvert during the 100-year, 12-hour duration storm as a result of the reduction in downstream backwater effects from implementation of this alternative. It appears these overflows during the 100-year, 12-hour duration storm event are passed easterly to the low point east of the eastern Landmark Plaza building and thus no improvements to the ditch south of Landmark Plaza are contemplated in this alternative. Component 2c–Downstream pipe upsizing to convey the 100-year flow We have analyzed upsizing the storm sewer system to convey the 100-year storm from Landmark Plaza to just upstream of the Campbell Creek Outfall at Durfee Avenue while allowing for a minimum of 1.5 feet of freeboard to the first floor elevation (762.28) of the building that flooded at Landmark Plaza. In this option, we replace the existing 36-inch x 58-inch CMP downstream of Landmark Plaza with either a 3-foot x 6-foot RCP Box, a 4-foot x 6-foot RCP Box, or two 3-foot x 4-foot RCP boxes as well as additional pipe upsizing on the Landmark Plaza as shown in Figure 4.03-1. With this option, some areas with very little cover in the area of the 4-foot x 6-foot box may need to be modified during design to use a custom 3-foot x 7-foot or alternate conveyance size to keep the pipe below ground with adequate cover. Street flooding continues to occur downstream of the Landmark Plaza during the 100- year storm event because of flows contributing from the South Branch Watershed and normal drainage from areas downstream of Landmark Plaza. This option is shown in Figure 4.03-1. The Opinion of Probable Costs for the alternative outlined above is shown in Table 4.03-1. ALTERNATIVE 2 - COMPONENT 2C DOWNSTREAM PIPE UPSIZING TO CONVEY THE 100-YEAR FLOW NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.03-11-382.021 Proposed 24" RCP (274 LF) Proposed 30" RCP (160 LF) Proposed 3' x 5'(320 LF) Proposed 21" RCPProposed 21" RCP Proposed 4' x 6' RCP Box(2131 LF) NOTE: PROPOSED BOX CULVERTS WOULD HAVE JUNCTION CHAMBERS EVERY 400' Proposed 3' x 6' Box Culvert(252 LF)TWIN 3' x 4' Box Culvert (1565 LF)To Replace Existing Northern Pipe WITZEL AVE N KOELLER ST SOUTHLAND AVE KNAPP ST BISMARCK AVE JOSSLYN ST MASON ST N SAWYER ST US HWY 41 SOUTHBOUND US HWY 41 NORTHBOUND S EAGLE ST S LARK ST N WESTFIELD ST S SAWYER ST GUENTHER ST N EAGLE ST FOSTER ST N WASHBURN ST PORTER AVE N MEADOW ST DOVE ST HAW K ST S WASHBURN ST DURFEE AVE W 4TH AVE LOMBARD AVE W 2ND AVE W 3RD AVE FAUST AVE N LARK ST SKYVIEW AVE NATIONAL AVE SULLIVAN ST GLEN AVE DEMPSEY TR CLAYTON CT W 4TH AVE N EAGLE ST W 4TH AVE N LARK ST SULLIVAN ST 762 764 758 746 768 756 770 774 776 778 780 752 760 750 748 766 754 0 756 758 770 756 758 770 754 760 754 758 752 0 0 760 762 764 760 760 0 762 758 0 752 0 0 756 756 752 770 752 762 762 762 0 766 0 758 764 762 760 0 754 0 754 764 754 0 754 752 756 764 760 764 766 762 758 764 752 762 762 754 756 758 758 760 758 754 764 764 760 0 756 760 0 750 756 766 7600 760 764 754 764 762 760 752 0 754 0 762 0 756 764 764 752 756 756 764 760 756 758 756 748 762 758 752 752 0 752 756 762 766 750 750 752 762 756 752 762 768 752 0 760 762 750 764 754 756 758 0 758 764 766 752 764 758 766 752 764 764 758 762 758 752 762 762 752 758 758 752 762 750 760 0 762 752 758 756 756 764 0 752 758 0 0 0 760 0 762 754 756 764 766 762 756 750 754 764 760 764 760 766 758 766 762 754 756 758 760 754 752 764 756 0 760 0 752 756 756 766 756 752 758 750 764 762 0 0 748 0 752 750 762 760 0 764 0 762 750 762 762 766 756 0 762 762 758 752 752 754 764 758 760 6 12 30 42 27 60 18 362221 5131 3658 0 6540 3150 20 36 3654 5031 8 24 10 15 2945 1930 12 12 27 3658 15 12 10 30 4224 18 24 27 24 18 3030 3658 12 18 21 15 3658 24 18 30 15 24 60 27 20 18 12 21 18 15 21 30 12 42 30 18 24 15 30 24 30 30 12 24 12 8 15 18 12 15 42 18 36 15 36 12 12 2442 30 24 15 3658 21 18 12 3658 15 15 10 18 12 3658 3658 12 18 24 36 15 18 24 21 24 30 24 3658 30 18 3658 3658 15 12 15 24 15 21 12 30 15 27 12 3658 21 12 15 30 15 18 30 12 30 18 18 21 60 15 15 12 21 12 24 15 12 6 12 12 12 21 24 12 12 15 12 12 15 12 15 8 12 42 21 15 18 S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative 2c.mxd 0 400 800200 Feet Legend Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) ALTERNATIVE 2 - COMPONENT 2A ADDITIONAL INTERNAL CAPACITY AT LANDMARK PLAZA NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.03-2A1-382.021 Proposed 156 LF - 30" @ 0.23% Q10 = 14.9 cfs CAP = 15 cfs Existing 100 YR CAP Existing 100 YR CAP Existing 100 YR CAP Existing 2 YR CAP (Due to High HGL & Low Inlet Elev. & Pipe Size) Q10 Input = 12.2 cfs (Future Cond.) Q10 Input = 11.9 cfs (Future Cond.) Proposed 267 LF - 24" @ 0.54% Existing 1 YR CAP (Due to High HGL & Low Inlet Elev. Not Pipe Size) 12 12 Q10 Input = 6.8 cfs (Future Cond.) Proposed 180 LF - 21" @ 0.13% Existing <1 YR CAP Existing 1 YR CAP Proposed 106 LF - 21" @ 0.93% WSEL 6/11/04 762.75 OVERFLOW OVERFLOW OVERFLOWOVERFLOW N KOELLER ST WITZEL AVE US HWY 41 NORTHBOUND S WESTFIELD ST W 5TH AVE WEST POINTE DR pvt LILAC ST N WESTFIELD ST MONTICELLO DR pvt 0 766 764 762 768770 774 776 778 772 780 782 784 760 786 766 770 0 762762 764 764 766 762 766 762 0 764 0 768 766 770 768 770 762 768 768 0 770 0 764 764 770 764 0 766 768 764 768 766 7660 764 764 768766 766 764 762 770 8 27 18 5131 36 0 3654 24 5836 21 20 15 30 6540 10 12 21 12 12 12 24 21 12 10 21 12 27 24 12 15 2021 12 12 8 24 24 18 12 1212 15 12 5836 24 10 5836 12 12 18 1224 21 12 12 24 18 15 18 10 24 12 12 18 18 12 21 12 12 12 15 12 S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative 2a.mxd 0 150 300 75 Feet Legend Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-11 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Component 2a–Additional Internal Capacity at Landmark Plaza 21-inch RCP (286 lf) 14,300 24-inch RCP (274 lf) 19,200 30-inch RCP (160 lf) 13,600 Inlet Manholes (4) 8,000 Pavement Restoration $10,800 Subtotal $65,900 Engineering and Contingencies (25%) 16,500 Total $82,400 Component 2b–Expansion of Ditch South of Landmark Plaza Not Necessary Component 2c–Downstream Pipe Upsizing to Convey the 100-year flow 3-foot x 4-foot RCP Box (3130 lf) 860,750 3-foot x 5-foot RCP Box (320 lf) 96,000 4-foot x 6-foot RCP Box (2131 lf) 852,400 Storm Sewer Junction Chambers (11) $231,000 Extra Inlets to Accept 100-year flows $100,000 Inlet Manholes (2) 4,000 Pavement Restoration 67,500 Erosion Control 15,000 Landscaping/Restoration 25,000 Subtotal $ 2,251,700 Engineering and Contingencies (25%) 562,900 Soils Investigation 2000 Total $ 2,816,600 GRAND TOTAL $2,899,000 Note: Costs do not include utility conflict resolution. Table 4.03-1 Alternative 2–Opinion of Probable Cost–Increase Conveyance Capacity in North Branch System The benefit of this alternative is shown in Table 4.03-2. Modeling indicates this alternative would meet the minimum 1.5-foot freeboard criteria (but less than the desirable 2 feet freeboard) for freeboard from the first floor elevation of the eastern Landmark Plaza building to the computed 100-year, 12-hour duration storm high water elevation in the Landmark Basin. However, this alternative has little impact on the number of streets flooding in the modeled area as shown in Table 4.13-2. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been eliminated according to the model (internal flooding of Landmark Plaza inlets notwithstanding). Under 100-year, 2-hour and 12-hour storm events, there is still some surface ponding at the parking lot inlets at Landmark Plaza and at the low point east of the eastern Landmark Plaza building. There will still be surface ponding and overflows through streets downstream of Landmark Plaza. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-12 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre- feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 3.32 0 N/A 10-year, 12-hour w/alternative 3.44 0 N/A 100-year, 2-hour w/alternative 1.70 0.34 Yes 100-year, 12-hour w/alternative 1.51 0.64 Yes June 11, 2004 w/ alternative (Existing Conditions) 3.10 0.0 N/A Average = 9 8 11 Table 4.03-2 Increased Conveyance Capacity Effects–Future Conditions–Alternative 2 4.04 ALTERNATIVE 3–FLOW DIVERSION MODIFICATION As shown in Figure 3.02-2, there are three locations along the west side of Washburn Street that act as stormwater diversions. The first is the ditch high point southeast of the intersection of Dickinson Avenue and S. Washburn Street (Diversion Point 1). This ditch begins to operate at prior to the 1-year storm event thus contributing flow to the north toward Sawyer Creek and the second diversion point. Under the 100-year, 2-hour duration storm event, the peak discharge over this high point (weir) is 119 cfs with 35 cfs discharging to the east under USH 41. One key to reducing the flooding and flows heading to the north at this point is to divert more stormwater to the east under USH 41 to the proposed Armory detention basin. This diversion capacity increase has been included as Component 1e of Alternative 1, Alternative 3, and all other alternatives except for Alternatives 2 and 4 where the expanded Armory detention is not a component of the alternative. The second diversion point (Diversion Point 2) is the culvert across USH 41 west of the Landmark Plaza. Our analysis shows that the upstream culvert end invert is 0.5 feet above the ditch flowing northerly to Sawyer Creek. Modeling shows this culvert begins to accept flow prior to a 1-year storm event. The ditches immediately downstream toward Sawyer Creek and north of Diversion Point 2 currently have 100-year capacities under existing conditions as shown in Figure 3.02-1. Diverting more flow north by restricting the flow across USH 41 and into Landmark Plaza with an 18-inch-diameter orifice plate is contemplated in this Alternative. Doing so also requires that approximately 2,700 linear feet of existing 60-inch RCP storm sewer (or a parallel pipe providing equivalent additional capacity) be upsized from north of Witzel Avenue to the Sawyer Creek/Washburn Street outfall as shown in Figure 4.04-1. In addition, this Alternative includes expanded detention at the Tippler, Westhaven Golf Course, and Armory ponds as well as new detention at W. 9th Avenue/Washburn Street as illustrated in Figures 4.04-2, 4.04-3, 4.02-1E, and 4.02-1C, respectively. It also includes upsizing of storm sewer upstream of the Tippler and Armory ponds to feed the expanded detention ponds as well as a new 3-foot by 6-foot RCP Box from W. 20th Avenue to the expanded Westhaven Golf Course Pond to feed the expanded 100-YEAR STORM SEWER IN DOT ROW NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.04-11-382.021 Landmark Plaza N KOELLER ST WITZEL AVE US HWY 41 SOUTHBOUND US HWY 41 NORTHBOUND N WESTFIELD ST N WASHBURN ST TAFT AVE GRACELAND DR S WASHBURN ST W 5TH AVE S WESTFIELD ST WESTBROOK DR LILAC ST ABBEY AVE SOUTHLAND AVE LOMBARD AVE REICHOW ST SULLIVAN ST SKYVIEW AVE LINWAY CT pvt US HWY 41 RAMP SULLIVAN ST 0 770 764 758 762 756 768 772 752 774 776782 750 784 760 778 748 766 780 754 760 0 0 758 756 766 776 0 756 0 750 770 0 766 750 774 756 776 758 780 764 766 0 778 772 770 0 0762 000 0 762 766 772 766 768 0 764 762 762 764 754 0 0 764 766 760 772 758 770 0 0 782 774 764 766 756 0 0 764 772 762 0 770 764 754 770 0 0 766752 772 772 762 770 756 768 0 768 762 760 0 766 77400 0 754 754 0 756 0 768 0 0 0 0 0 756 760 754 762 0 760 754 0 0 770 0 764 774 0 754 762 772 772 764 780 754 774 762 0 768 768 766 760 750 752 754 0 0 776 768 764 0 758 762 0 764 754 762 758 762 760 770 770 762 758 760 760 0 0 0 0 758 762 0 0 0 0 0 764 760 768 0 754 760 772 0 0 762 0 768 758 752 770 0 0 760758 0 758 764 772 776 0 758 756 772 0 756 0 762 756 0 0 0 764 774 774 0 770 770 0 762 0 772 774 0 0 778 764 772 0 762 0 770 760 766 0 758 772 756 0 762 768762 764 764 772 760 764 774 772 0 772 764 756 758 0 764 0 758 754 760 0 764 0 0 760 0 0 0 772 762 0 0 0 758 768 0 764 756 762 774 0 778 764 756 0 772 766 754 766 766 766 770 772 760 756 752 756 772 774 0 762 0 768 0 756 756 762 762 0 770 762 772 776 774 758 0 0 762 760 754 764 760 0 0 0 0 756 0 758 764 756 0 754 748 756 770 764 756 760 0 776 0 760 760 0 756 0 0 764 772 0 0 0 0 0 758 0 0 764 772 752 60 6 30 0 24 8 21 42 4065 27 51314472 123615 5836 3658 10 18 1423 30 21 12 12 27 18 18 18 12 18 4065 12 18 12 6 12 150 12 10 24 24 18 18 30 1018 24 15 12 10 21 8 12 12 42 18 12 12 12 5836 24 12 12 12 15 8 12 24 12 12 12 15 8 15 12 276 60 30 0 12 15 30 15 15 10 60 12 12 4065 18 18 21 15 18 12 12 8 15 30 15 12 12 12 21 18 18 0 12 15 21 12 12 21 10 21 18 18 12 60 18 18 18 15 18 12 36583658 24 30 88 12 12 2112 21 15 128 27 18 36 18 15 24 12 12 12 15 18 21 12 S:\@sai\351--400\382\021\GIS\Report Figures\100-Year Storm Sewer In DOT ROW.mxd 0 400 800 200 Feet Legend Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) Existing = 60" RCP Proposed Storm Sewer (2673 LF) ALT-3 = 5x5 Box Culvert ALT-6 = 5x6 Box Culvert ALT-7 = No Change ALT-8 = 5x6 Box Culvert ALT-9 = No Change ALT-10 = 5x6 Box Culvert ALT-11 = No Change Existing = 60" RCP Proposed Storm Sewer (299 LF) ALT-3 = No Change ALT-6 = 66-inch RCP ALT-7 = No Change ALT-8 = 66-inch RCP ALT-9 = No Change ALT-10 = 66-inch RCP ALT-11 = No Change Existing = 3' x 4.5' Box Landmark Diversion ALT-3 = Steel Plate w/Orifice (18-inch Dia.) ALT-6 = Bulkhead ALT-7 = Steel Plate w/Orifice (34-inch Dia.) ALT-8 = Bulkhead ALT-9 = No Change ALT-10 = Bulkhead ALT-11 = No Change ALTERNATIVE EXPANDED TIPPLER DETENTION NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.04-21-382.021 Maintain OverlandFlow Routes IE = 753.61 Proposed ManholeIE = 753.52 405 LF - 12" PVC@ 0.20% Proposed ManholeIE = 752.70 70 LF - 12" PVC@ 0.20% IE = 752.84 435 LF - 12" PVC@ 0.20% 52 LF - 12" PVC@ 0.20% Proposed ManholeIE = 751.83 67 LF - 36" x 60" HERCP @ 0.25%IE = 752.00 480 LF - 12" PVC@ 0.165% Proposed ManholeIE = 752.79 IE = 752.91 110 LF - 12" PVC@ 0.10% IE = 753.52 Proposed ManholeIE = 753.45 35 LF - 12" PVC@ 0.20% 400 LF - 12" PVC@ 0.165% IE = 752.00 Normal WSEL = 752.00 754 754 754 754 754 754 753 753 752 755 175' LotDepth 120' AdditionalParking Maintain OverlandFlow Routes Provide Fill to RaiseProperty Above Over LandFlow Route Elevations High CapacityInlets at Low Points FootballField ALT-7Channel Regradingand Twice YearlyDitch Maintenance ALT-7Twice YearlyDitch Maintenance ALT-7Additional 46 LF27" RCPParallel to ExistingStorm Sewer SoccerField WITZEL AVE S EAGLE ST N KOELLER ST BISMARCK AVE US HWY 41 SOUTHBOUND US HWY 41 NORTHBOUND S WESTFIELD ST S WASHBURN ST W 4TH AVE W 2ND AVE N EAGLE ST N MEADOW ST LILAC ST N WESTFIELD ST MONTICELLO DR pvt 0 766 762 764 760 768 770 758 774776 778 780782 784 786 762 764 766 770 762 766 0 764 766 762 0 762 0 0 764 764 768 758 0 00 760 766 764 762 764 768 762 764 764 764 760 0 758 764 764 764 770 0 764 768 762 770 768 766 0 762 0 766 0 0 0 762 762 0 766 762 762 764 766 762 764 0 764 770 5836 18 27 8 21 24 42 15 30 12 3658 5131 36 3654 10 20 2945 2820 12 15 12 24 24 18 15 12 12 21 24 12 12 12 18 12 18 24 21 12 24 18 12 15 21 15 27 12 S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative Expanded Tippler Detention.mxd 0 200 400100 Feet Legend Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) Landmark Diversion ALT-3 = Steel Plate w/Orifice (18" Dia.)ALT-6 = BulkheadALT-7 = Steel Plate w/Orifice (34-inch Dia.)ALT-8 = BulkheadALT-9 = No ChangeALT-10 = BulkheadALT-11 = No Change Proposed Box Culvert(107 LF) ALT-3 = 3 x 4ALT-6 = 3 x 4ALT-7 = 3 x 5ALT-8 = 3 x 4ALT-9 = 3 x 5ALT-10 = 3 x 4ALT-11 = 3 x 5 Proposed Box Culvert(377 LF) ALT-3 = 3 x 4ALT-6 = 3 x 4ALT-7 = 3 x 5ALT-8 = 3 x 4ALT-9 = 3 x 4ALT-10 = 3 x 4ALT-11 = 3 x 4 Proposed Box Culvert(107 LF) ALT-3 = No ChangeALT-6 = No ChangeALT-7 = 3 x 5ALT-8 = No ChangeALT-9 = No ChangeALT-10 = No ChangeALT-11 = No Change ALTERNTATIVE EXPANDED GOLF COURSE NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.04-31-382.021 IE = 807 Existing Ditch Railroad Tracks Provide Inlets at Intersection to Collect 100 YR Flow 2765 LF - 3' x 6' Box Culvert Provide Inlets to Collect 100 YR Flow IE = 776.49 Bulkhead Existing Storm Sewer to East 434 LF - 34" x 53" HERCP @ 0.23% IE = 775.5 IE = 775.5 IE = 774.95 359LF - 18" RCP @ 0.15% Provide Drainage Swale Around Perimeter of Pond IE = 775.5 IE = 775.5 IE = 775.5 673 LF - 43" x 68" HERCP @ 0.41% 647 LF - 24" x 38" HERCP @ 0.13% Connect to Existing Manhole IE = 776.32 Provide Inlets at Intersection to Collect 100 YR Flow Bulkhead Existing Storm Sewer to North IE = 778.91 145 LF - 43" x 68" HERCP @ 0.41% Provide Inlets at Low Point to Collect 100 YR Flow Normal WSEL = 775.50 Provide Inlet at Low Point to Collect 100 YR Flow SCB-90 SCB-91 SCB-76 SCB-85 SCB-75 SCB-92 SCB-70 SCB-80 SCB-90 SCB-65 W 20TH AVE MARICOPA DR ALLERTON DR S WESTHAVEN DR VILLA PARK DR COVINGTON DR S WASHBURN ST ARLINGTON DR THORNTON DR DEERFIELD DR UNIVERSAL ST GREENFIELD TR HERITAGE TR CUMBERLAND TR CAMDEN LN VILLAGE LN VIKING PL NEWPORT CT S WESTHAVEN DR 786 798 794 796 800 792 790 784 782 806 788 810 818 780 804 778 812 808 776 820 824 830 814 774 832 780 808 782 784 782 786 792 798 788 788786 778 778 790 788 784782 782 780 788 780 780 788 780 780 790 786 780 786 782 790 786 792 788 786 790 792 820 784 776 782 786 782 786 782 776 786 782 794 788 830 810 786 790 782 784 790 808 788 782 800 830 790 786 782 792 810 824 820 780 780 790 788 788 780 792 792782 790 778 820 794 800 820 792 790 808 782 780 818 820 780 786 786 780 782 782 784 796 780 792 790 782 810 786 790 778 784 782 786 784 782 788 788 788 786 792 786782 782 798 782 792 782 810 780 794 782 788 790 810 784 778 792 792 788 788 784 782 788 798 820 782 784 790 788 778 786 790 778 780 788 784 810 786 786 820 782 790 784 794 784 782 784 800 788 810 780 790 790 784 794 788 806 788 786 792 796 788 784 830 820 776 782 808 778 790 788 786 782 792 788 782 780 782 790 784 786 810 780 782 794 780 784 782 782 786 786 786 784 790 792 788 794 784 830 782 778 792 780 812 778 778 790 788 786 784 786 784 786 786 792 782 780 792 784 788 780 812 42 6 24 10 12 27 1930 21 8 0 18 15 30 8 15 12 15 18 8 15 18 12 8 18 8 21 42 12 0 24 10 30 15 15 8 42 15 15 8 12 1515 12 12 12 24 12 8 8 18 12 12 30 12 12 30 12 12 8 15 12 42 8 18 12 15 27 8 8 15 8 21 24 21 24 18 12 15 24 18 21 15 8 8 15 15 24 27 30 15 30 10 24 8 21 1515 15 12 10 12 18 8 1515 12 24 24 12 12 12 12 12 12 8 18 12 15 8 8 15 15 12 30 8 12 15 12 15 15 18 15 12 21 24 30 24 12 8 18 8 18 18 15 27 12 12 12 12 8 18 18 12 12 18 30 18 15 12 S:\@sai\351--400\382\021\GIS\Report Figures\Alternative Expanded Golf Course.m xd 0 400 800 200 Feet Legend Proposed Drainage Basin Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-13 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 golf course pond as shown in Figures 4.04-2, 4.02-1E, and 4.04-3, respectively. Each of the components of this Alternative are described below. The third diversion point (Diversion Point 3) is the culvert across USH 41 north of Witzel Avenue. This diversion point begins to operate at the 100-year, 2-hour duration event under existing conditions and does not appear to cause backflow into the upstream system. Taking more flow across USH 41 at this location would only cause further flooding problems in the N. Westfield Drive area and is not recommended. The following are the components considered under Alternative 3. Component 3a–Expanded Tippler Junior High Detention Basin–The expanded Tippler pond would have a small wet pond in the center but would operate essentially as a dry detention pond during periods when it isn’t raining. The basin is sized so that a soccer field and a football field could fit on the bottom of the basin. During final design, a dry detention pond without a wet pond in the center will be analyzed to achieve similar performance to the dry pond/wet pond combination. Because of the diversion modification on the storm sewer entering the Landmark Plaza lands, the full use of the storage provided by this pond is not realized. The full cost and use of this detention basin as described under Alternative 7, Component 7a is $1,783,100 and storage volume used is 50 acre-feet. In Alternative 3, only 31 acre- feet of storage are used, so this pond could be reduced in size and volume. For this reason, we have reduced the cost of this detention basin under Alternative 3 by $349,100 to account for reduced excavation and restoration costs. Component 3b–Expanded Detention at Armory (See Component 1e above) Component 3c–Expanded Detention at W. 9th Avenue/Washburn Street (See Component 1c above)– Because of the diversion of stormwater that originally would have drained to the W. 9th Avenue/Washburn Street detention basin to the Expanded Westhaven Golf Course detention basin, the full use of the storage provided by this pond is not realized. The full cost and use of this detention basin as described under Alternative 1 is $1,812,300 and storage volume used is 31 acre-feet. In Alternative 3, only 16.5 acre-feet of storage are used, so this pond could be reduced in size and volume. For this reason, we have reduced the cost of this detention basin under Alternative 3 by $674,400 to account for reduced excavation and restoration costs. Component 3d–Expanded Golf Course Detention–This pond can only realize its entire volume by creating multiple connections from upstream lands that previously drained elsewhere. The most significant connection is a 3-foot by 6-foot RCP box (2765 lf) connection leading from W. 20th Avenue. Of the 908 cfs coming to the point where this box culvert would divert stormwater to the golf course pond, this box culvert would divert 127 cfs of this to the golf course pond. This diversion will help to lessen the flooding along the railroad tracks southeast of Allerton Drive as well as along S. Washburn Street between W. 20th Avenue and W. 9th Avenue. Under the 100-year, 12-hour duration storm event, this pond would pond to elevation 780.6, which would provide 120 acre-feet of storage, easily the largest of the ponds considered in the alternatives. If the City is able to locate this 120 acre-feet of City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-14 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 storage elsewhere in the watershed upstream of W. 20th Avenue at a lower cost because of less need for piping to feed the basin and/or lower land costs, this may be advisable. Component 3e–Storm Sewer from Landmark Plaza to Expanded Tippler Detention Basin–To properly feed the Expanded Tippler Detention Basin and alleviate backwater effects downstream of Landmark Plaza, it is necessary to upsize the pipe leading from Landmark Plaza to the Expanded Tippler Detention Basin from an existing 36-inch by 58-inch CMP to a 3-foot by 4-foot RCP Box as shown in Figure 4.04-2. Component 3f–100-Year Storm Sewer in DOT ROW Downstream of Witzel Avenue–In order to offset the effects of the reduced diversion into Landmark Plaza, the existing storm sewer along Washburn Street from north of Witzel Avenue to the Sawyer Creek/Washburn Street outfall must be upsized from an existing 60-inch RCP to a 5-foot by 5-foot RCP Box as shown in Figure 4.04-1. The Opinion of Probable Costs for the improvements outlined above is shown in Table 4.04-1. The cost for the detention at W. 9th Avenue/Washburn Street has been reduced by $481,210 from the cost contemplated for this detention in Alternative 1 (Component 1C). This reduction is included because the full capacity of the W. 9th Avenue/Washburn Street detention basin isn’t realized with this option because of a portion of the upstream flow is diverted into the expanded Westhaven Golf Course detention pond. The pond could thus be reduced in size to the approximate size that is being used in this alternative. This leads to reductions in the costs of excavation and restoration. The benefit of this alternative is shown in Table 4.04-2. Modeling indicates this alternative would meet the desirable 2 feet of freeboard at the eastern Landmark Plaza building for the 100-year, 2-hour duration storm event. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been eliminated according to the model (internal flooding of Landmark Plaza inlets notwithstanding). Under 100-year, 2-hour and 12-hour storm events, there is still some surface ponding at the parking lot inlets at Landmark Plaza and at the low point east of the eastern Landmark Plaza building. This alternative is ranked third for watershed-wide benefit. For this alternative, the City would be able to claim total suspended solids (TSS) reductions for the expanded Tippler, Westhaven Golf Course and W. 9th Avenue/Washburn Street ponds. Depending on the final arrangement of the expanded Armory pond (if the pond can be expanded to the north and incorporate the existing ditch thus accepting all flows, not allowing the 2-year flow to divert the pond through the existing ditch), the City may also be able to claim TSS reductions to help meet the Phase 2 DNR requirements of 20 percent and 40 percent TSS by March 10, 2008, and March 10, 2013, respectively. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-15 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Component 3a–Expanded Tippler Junior High Detention Basin (see component 7a) $1,434,000 Component 3b–Expanded Detention at Armory (See Component 1e above) $3,459,700 Component 3c–Expanded Detention at 9th Avenue/Washburn Street (See Component 1c above) – Cost reduced $481,200 due to less use of pond storage $1,137,900 Component 3d–Expanded Golf Course Detention Excavation $4,375,900 Riprap 4,500 Piping and Structures 340,000 3-foot x 6-foot RCP Box (2765 lf) 829,500 Storm Sewer Junction Chambers (7) 147,000 Extra Inlets to Accept 100-year Flows 48,000 Erosion Control 15,800 Pavement Restoration 14,800 Landscaping/Restoration 129,800 Subtotal 5,905,300 Engineering and Contingencies (25%) 1,476,300 Subtotal 7,381,600 Soils Investigation $4,000 Land Acquisition (44.45 acres @ $20,000/ac) 889,000 Total $8,274,600 Component 3e–Storm Sewer from Landmark Plaza to Expanded Tippler Detention Basin 3-foot by 4-foot RCP Box (357 lf) and 3-foot by 4-foot AEW 103,200 100-Year Inlet Capacity on Westfield Street 7,200 Storm Sewer Junction Chamber and High Capacity Inlet at Landmark Plaza $27,000 Curb and Gutter and Asphalt Restoration $900 18-inch diameter steel plate orifice upstream of USH 41 1,000 Subtotal $139,300 Engineering and Contingency (25%) 34,800 Total $174,100 Component 3f – 100-year Storm Sewer in DOT ROW downstream of Witzel Remove 5-foot diameter RCP storm sewer (2673 lf) $53,500 5-foot by 5-foot RCP Box (2673 lf) 1,136,000 5-foot by 5-foot Apron Endwall (2) 10,000 Storm Sewer Junction Chamber (7) $147,000 Pavement Replacement $40,100 Subtotal 1,386,600 Engineering and Contingencies (25%) $346,700 Total $1,733,300 Grand Total $16,213,600 Note: Costs do not include utility conflict resolution. Table 4.04-1 Alternative 3–Opinion of Probable Cost–Diversion Modification City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-16 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre-feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 3.24 0 N/A 10-year, 12-hour w/alternative 3.55 0 N/A 100-year, 2-hour w/alternative 2.02 0.13 Yes 100-year, 12-hour w/alternative 3.36 0 Yes June 11, 2004 w/ alternative (Existing Conditions) 3.34 0 N/A Average = 4 5 3 Table 4.04-2 Diversion Modification Effects–Future Conditions–Alternative 3 4.05 ALTERNATIVE 4–STORMWATER PUMP STATION AT DOWNSTREAM END OF CAMPBELL CREEK To offset the effects of high lake levels, we have analyzed the use of a pumping system to maintain the capacity of the Campbell Creek Main Stem storm sewer outfall pipe at the maximum flow during surcharged conditions (171 cfs). This analysis employs use of check valves on the discharge pipe, an upstream diversion structure that diverts to a pump station, a pump station to pump at a rate slightly exceeding the storm sewer system capacity (maximum 200 cfs), and a discharge pipe line into Campbell Creek and the backwaters of the Fox River. This option is shown in Figure 4.05-1. The pump station would be sited on parcel number 90609600000 that is 0.58 acres in area. The pump station would intercept stormwater at Witzel Avenue through an underground concrete junction box near the existing 72-inch x 44-inch elliptical pipes. New 60-inch-diameter outlet pipes from this junction box would discharge to the existing channel that empties into Campbell Creek. The ends of the outlet pipes would contain check valves to prevent water from Campbell Creek from flowing back into the storm drainage system. During storm events, runoff in the storm system would flow into a new concrete supply channel parallel to Witzel Avenue and into a new open concrete storage reservoir. The storage reservoir would have an approximate active storage of 400,000 gallons. An adjacent pump house with three axial flow pumps would convey the stormwater from the reservoir through a new 6.5- foot-diameter buried force main to an outlet in Campbell Creek. The stormwater lift pumps would be activated by a series of float mechanisms in the reservoir. The pump house would contain an emergency backup generator to allow full operation of the pump station during a power outage. In the event of a complete system failure, the reservoir would fill and the stormwater would begin to surcharge in the system as it currently occurs during high flow events. If the influent elevation exceeds the elevation of the water in the discharge channel to Campbell Creek, the Tideflex check valves will open allowing normal passage of the storm flow. However, the upstream storm sewer system will remain surcharged until the pump station is operational again. ALTERNATIVE 4 STORMWATER PUMP STATION AT DOWNSTREAM END OF CAMPBELL CREEK NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.05-11-382.021 Campbell Creek Existing Channel Pipeline to Campbell Creek (385 LF - 72") 200 CFS Pump Station Perimeter Fencing 65' x 80' x 14' D Concrete Reservoir 60" Ø Discharge Pipes with Tideflex Valves (TYP) Concrete Junction Box Existing 72" x 44" Elliptical Storm Drain Pipes 120 LF - 2 - 34" x 53" HERCP @ 1%IE = 741.00 IE = 740.00 IE = 743.19 IE = 744.39 WITZEL AVE DURFEE AVE S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative 4.mxd 0 60 120 30 Feet Lege nd Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-17 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Site Work and Structural 954,430 Valves $28,200 Interior Piping and Fittings $103,180 Conveyance $382,250 Pumps $205,000 Electrical 264,950 Erosion Control 2,000 Subtotal 1,940,000 Engineering and Contingencies (25%) $485,000 Subtotal $2,425,000 Soils Investigation 5,000 Land Acquisition (0.58 acres[25,265sf] @ $10/sf) $252,600 Total $2,682,600 Note: Costs do not include utility conflict resolution. Table 4.05-1 Opinion of Probable Cost–Stormwater Pump Station–Alternative 4 The pump station would be sized for a design flow rate of 200 cfs, which is slightly greater than the 100-year, 2-hour storm flow (future conditions) of 171 cfs in the outfall pipe according to the modeling completed on the system. Three pumps would be used in the system to handle varying flow rates. A single 100 hp pump would be used to handle smaller storm events. During larger storm events, two 300 hp pumps would handle peak incoming flows. The pump station would require a sizeable reservoir to slightly attenuate the flows. At a design flow rate of 200 cfs, the reservoir would contain approximately 4.5 minutes of storage, which should be adequate to allow smooth operation of a multiple pump system. The estimated cost for the Campbell Creek Pump Station and associated structures and piping is $2,600,000 as shown in Figure 4.05-1. Many factors such as backup generation capability, capacity of station, and type/size of reservoir impact this alternative. The large capacity of the pumps and the relative size of the equipment to handle the design flow contribute to the high cost of this alternative. The Opinion of Probable Costs for the alternative outlined above is shown in Table 4.05-1. Our engineering analysis shows this alternative will have a negligible effect on flooding at the Landmark Plaza as shown in Table 4.05-2. Modeling indicates this alternative would not meet the minimum 1.5 feet of freeboard at the eastern Landmark Plaza building for any of the storm events analyzed. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been reduced slightly according to the model (16.56 acre-feet down to 14.06 acre-feet) in the Landmark Basin but would still have flooded the eastern Landmark Plaza building by about 3 inches (0.25 feet). This alternative has the lowest rank of all of the alternatives. In fact, it has the potential to exacerbate or have little effect on flooding problems in certain areas in the watershed for certain storm events as evidenced by the total ponding allowed and number of streets flooding columns in Table 4.13-3. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-18 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Component 1a–Detention South of Landmark Plaza $1,430,400 Component 1d–Detention at Tippler Junior High $691,800 Component 1e–Detention and Pipe Upsizing at Armory $3,459,700 Total $5,581,500 Note: Costs do not include utility conflict resolution, if any. Costs do include Engineering and Contingency (25%) and land acquisition costs as described in previous alternatives. Table 4.06-1 Alternative 5–Opinion of Probable Cost Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre- feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 0.52 5.67 N/A 10-year, 12-hour w/alternative -0.07 11.85 N/A 100-year, 2-hour w/alternative -0.15 12.82 No 100-year, 12-hour w/alternative -0.30 14.71 No June 11, 2004 w/ alternative (Existing Conditions) -0.25 14.06 N/A Average = 11 11 10 Table 4.05-2 Pump Station Effects–Future Conditions–Alternative 4 4.06 ALTERNATIVE 5–ORIGINAL MIX OF PROJECT COMPONENTS From the project components considered above, we have analyzed a mix of project components as a modification of Alternative 1. This alternative includes the following components and is shown in Figure 4.02-1 as described above in Section 4.02: 1. Detention at vacant parcel south of the Landmark Plaza (6.2 acre-feet). 2. Detention at Tippler Junior High property (24.5 acre-feet). 3. Detention at the Armory site (48.8 acre-feet) and upstream pipe upsizing (flow diversion modification as discussed in Alternative 3 and implemented in Alternative 1 (Component 1e) to feed the basin. The Opinion of Probable Costs for the alternative outlined above is shown in Table 4.06-1. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-19 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre-feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 1.93 0.17 N/A 10-year, 12-hour w/alternative 1.68 0.37 N/A 100-year, 2-hour w/alternative 0.56 5.34 No 100-year, 12-hour w/alternative -0.02 11.25 No June 11, 2004 w/alternative (Existing Conditions) 0.16 9.15 N/A Average = 10 10 9 Table 4.06-2 Future Conditions Effects–Alternative 5 Our engineering analysis provided in Table 4.06-2 shows that while there is some reduction in flooding at the Landmark Plaza, there is still substantial flooding there. While the benefit at Landmark Plaza is smaller than Alternative 1, the addition of this detention will allow other areas including streets and low points to flood less frequently. The overall effect of Alternative 5 is included in Table 4.06-2. Modeling results indicate the eastern Landmark Plaza building would flood about 0.02 feet (one-quarter inch) during the 100-year, 12-hour storm event and there would be substantial surface ponding and surface overflows in the Landmark Basin. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been reduced by roughly 45 percent (16.56 acre-feet down to 9.15 acre-feet) and the eastern Landmark Plaza building would not have flooded (0.16 feet of freeboard). However, this alternative does not meet the freeboard criteria at Landmark Plaza of a minimum of 1.5 feet of freeboard with 2.0 feet being desirable. In summary, modeling of Alternative 5 indicates that provision for detention at these locations alone is not sufficient to alleviate flooding at Landmark Plaza in conformance with the plan goals. However, the addition of detention to the watershed will have additional major benefit in other areas including streets and low points that currently. This alternative has the second lowest overall average ranking. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-20 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Component 6a–Expanded Detention at Tippler Junior High property $1,104,400 Component 6b–Expanded Detention at Armory Site (see component 1e) $3,459,700 Component 6c–Detention at 9th Avenue/Washburn Street (see component 1c) $1,812,300 Component 6d-Storm Sewer Upsizing from Landmark Plaza to Tippler 3-foot by 4-foot RCP Box (357 lf) and 3-foot by 4-foot AEW 103,200 100-Year Inlet Capacity on Westfield Street 7,200 Storm Sewer Junction Chamber and High Capacity Inlet at Landmark Plaza $27,000 Curb and Gutter and Asphalt Restoration $900 Bulkhead of Diversion upstream of USH 41 1,000 Subtotal $139,300 Engineering and Contingency (25%) $34,800 Total $174,100 Component 6e-100-Year Storm Sewer in DOT right-of-way Remove 5-foot diameter RCP storm sewer (2673 lf) $53,500 5-foot by 6-foot RCP Box (2673 lf) 1,202,900 5-foot by 6-foot Apron Endwall (2) 10,000 Storm Sewer Junction Chamber (7) $147,000 Remove 5-foot diameter RCP under Witzel $6,000 66-inch RCP Storm Sewer (299 lf) and 66-inch AEW w/grate $40,100 Pavement Replacement and Restoration $44,600 Subtotal $1,504,100 Engineering and Contingency (25%) $376,000 Total $1,880,100 Grand Total $8,430,600 Note: Costs do not include utility conflict resolution, if any. Table 4.07-1 Alternative 6–Opinion of Probable Cost 4.07 ALTERNATIVE 6 Alternative 6 includes the following mix of project components as described below. 1. Expanded Detention (20.8 acre-feet) at Tippler Junior High property (Figure 4.04-2)– Cost reduced by $678,670 from that shown in Alternative 7 for reduction in pond size due to nonrealization of full storage volume due to elimination of diversion across USH 41 at Landmark Plaza. 2. Expanded Detention (50.5 acre-feet) at the Armory site and upstream pipe upsizing (flow diversion modification as discussed in Alternative 3 and implemented in Alternative 1 (Component 1e) to feed the basin (Figure 4.02-1E). 3. 31.2 acre-feet of detention at W. 9th Avenue and Washburn Street (Figure 4.02-1C). 4. Storm Sewer Upsizing from Landmark Plaza to Tippler (Figure 4.04-2). 5. Construction of new 100-Year Storm Sewer in DOT right-of-way to the north of Diversion Point 2 along Washburn Street to allow for the elimination of Diversion Point 2 crossing USH 41 west of Landmark Plaza (Figures 4.04-1 and 4.04-2). The Opinion of Probable Costs for the alternative outlined above is shown in Table 4.07-1. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-21 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre-feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 3.23 0 N/A 10-year, 12-hour w/alternative 3.55 0 N/A 100-year, 2-hour w/alternative 2.02 0.13 Yes 100-year, 12-hour w/alternative 3.54 0 Yes June 11, 2004 w/ alternative (Existing Conditions) 3.55 0 N/A Average = 6 3 7 Table 4.07-2 Future Conditions Effects–Alternative 6 The benefit of this alternative is shown in Table 4.07-2. Modeling indicates this alternative would meet the desirable 2 feet of freeboard at the eastern Landmark Plaza building for the 100-year, 2-hour duration storm event. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been eliminated according to the model (internal flooding of Landmark Plaza inlets notwithstanding). Under 100-year storm event, there is still some surface ponding at the parking lot inlets at Landmark Plaza and at the low point east of the eastern Landmark Plaza building. This alternative is ranked 7th for watershed-wide benefit. This is partially due to the increased peak discharge rate at the Sawyer Creek/Washburn Street outfall. For this alternative, the City would be able to claim TSS reductions for the expanded Tippler and W. 9th Avenue/Washburn Street ponds. Depending on the final arrangement of the expanded Armory pond (if the pond can be expanded to the north and incorporate the existing ditch thus accepting all flows, not allowing the 2-year flow to divert the pond through the existing ditch), the City may also be able to claim TSS reductions to help meet the Phase 2 DNR requirements of 20 percent and 40 percent TSS by March 10, 2008, and March 10, 2013, respectively. 4.08 ALTERNATIVE 7 From the alternatives considered above, we have analyzed the following mix of project components as shown in Figure 4.08-1: 1. Expanded Detention (44.7 acre-feet) at Tippler Junior High property (Figure 4.04-2)– The cost provided below is the full cost of this pond because the full pond volume is used. This cost has been reduced in Options 3, 6, 8, and 10 because of nonrealization of full storage volume due to elimination or modification of the diversion across USH 41 at Landmark Plaza. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-22 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 2. Expanded Detention (50.7 acre-feet) at the Armory site and upstream pipe upsizing (flow diversion modification as discussed in Alternative 3 and implemented in Alternative 1 (Component 1e) to feed the basin (Figure 4.02-1E). 3. Detention (31.1 acre-feet) at W. 9th Avenue and Washburn Street (Figure 4.02-1C). This figure shows a dry pond/wet pond combination. During final design, a dry detention pond without a wet pond in the center will be analyzed to achieve similar performance to the dry pond/wet pond combination and achieve the freeboard goals. 4. Storm Sewer Upsizing from Landmark Plaza to Tippler (Figure 4.04-2). 5. Provision for twice-yearly maintenance (mowing and debris removal) on the first ditch segment (modeled ditch number D-AEW-11) downstream from the Diversion Point 2 outfall into Landmark Plaza to allow for a more efficient cross section (change from Manning’s “n” of 0.10 to 0.075). 6. Construction of a 27-inch-diameter storm sewer culvert parallel to the existing 31- inch by 51-inch RCP (modeled node P-LP-1) just downstream from ditch D-AEW-11. 7. Reconstruction and regrading of the two downstream-most ditch segments (D-LP-4 and D-LP-5) in Landmark Plaza with a cross section consisting of a 2-foot width bottom and maximum 2 H : 1 V side slopes to eliminate the current high point at node LP-5. This would also include provision for twice-yearly maintenance (mowing and debris removal) to allow for a more efficient cross section (change from Manning’s “n” of 0.10 to 0.075). 8. Construction of a 34-inch-diameter orifice plate on the upstream end of the existing 3-foot by 4.5-foot RCP box that crosses USH 41 at Diversion Point 2 to reduce flows able to enter Landmark Plaza. This reduction in flow still allows for the approximate capacity of the ditches and storm sewers along Washburn Street downstream of Diversion Point 2 to still be at a 100-year capacity under future conditions. ALTERNATIVE 7 - COMPONENTS NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.08-11-382.021 Tippler Detention Channel Regrading and Twice Yearly Ditch Maintenance Twice Yearly Ditch Maintenance Additional 46 LF 27" RCP Parallel to Existing Storm Sewer 34" DIA Orifice Plate Upgrade Storm Sewer to 3' x 5' Upgrade Storm Sew er to 38" x 60" HERCP Total Length = 1021 LF Armory Detention Detention at 9th Ave and Washburn St FOREBAY FOREBAY WITZEL AVE S WASHBURN STUS HWY 41 SOUTHBOUND US HWY 41 NORTHBOUNDN KOELLER ST 9TH AVE S KOELLER ST W 9TH AVE S EAGLE ST REICHOW ST W 5TH AVE US HWY 41 RAMP S WESTFIELD ST OSBORN AVE LILAC ST ARMORY PL GRACELAND DR MARICOPA DR MORELAND ST ABBEY AVE W 6TH AVE W 7TH AVE WINDSOR ST CUMBERLAND TR N EAGLE ST BISMARCK AVE CRYSTAL SPRINGS AVE WESTBROOK DR N WESTFIELD ST DICKINSON AVE MENARD DR S WESTFIELD ST US HWY 41 RAMP W 7TH AVE 0 768 774 776 780 778 770772 764 766 762 760 758 756 754 752 750 748 746 744 742 708 782 704 702 784 700 698 786 696 790 788792 794 694 0 772 0 774 778 768 776 786 784 780 782 778 774 770 784 778 768 770 784 762 778 782 0 784 782 772 762 780 772 776 778 0 762 776 782 778 774 0 780 0 782 778 776 0 774 758 782 776 764 766 764 0 762 768 780 762 774 766 766 778 786 772 786 782 764 0 776 784 784 0 0 772 776 774 0 758 782 778 770 778 792 778 784 770 772 764 780 764 780 774 788 790 770 0 766 770 772 774 766 778 766 0 774 774 0 786 780 782 774 776 782 762 764 776 778 768 782 0 778 786 772 780 0 772 774 768764 778 770 762 772 780 0 782 772 786 0 764 0 780 780 764 780 766 778 772 780776 764 784 0 772 778 780 782 772 774 770 772 772 774 778 774 772 776 772 0 778 0 776 780 0 778 782 776 0 766 758 784 780 780 0 780 774 782 770 780 782 778 778 770 778 0 780 776 782 778762 772 774 778 778 782 778 776 780 782 780 768 696 780 774 774 0 770 762 776 780 778780 778 770 774 772 778 776 776 0 772 770 0 780 700 784 774 784 780 772 0 772 774 772 772 778 780 782 774 770 760 762 778 0 780 770 778 778 774 780 776 776 780 776 782 778 0 778 0 786 704 772 778 782 772 774 782 768 782 782 774 0 772 0 0 780 780 764 0 0 778 778 770 0 42 48 15 5836 24 27 18 2516 12 6 8 21 36 54 60 30 5031 3658 1930 5131 0 1423 10 20 6540 12 12 12 24 5836 15 18 0 24 48 12 21 27 27 1221 18 24 21 8 18 12 24 12 24 1227 18 12 21 15 15 18 8 12 27 8 10 48 24 12 10 15 30 12 12 18 24 27 12 12 12 8 8 12 12 10 8 12 12 12 15 12 18 24 21 24 18 12 18 27 18 18 24 42 10 12 10 12 12 24 15 12 12 12 15 21 8 42 30 3658 12 21 18 12 12 15 18 12 8 21 15 12 15 15 12 12 12 8 24 24 8 12 S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative 7.mxd 0 450 900 225 Feet Legend Storm Manhole Storm Sew er Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) Proposed Detention Proposed Pipe City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-23 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Component 7a–Expanded Detention at Tippler Junior High property Excavation $816,000 Riprap 3,400 Piping and Structures 96,100 Erosion Control 9,700 Landscaping/Restoration 333,900 Subtotal 1,259,100 Engineering and Contingencies (25%) 314,800 Subtotal 1,573,900 Soils Investigation $3,000 Land Acquisition (10.31 acres @ $20,000/ac) 206,200 Total $1,783,100 Component 7b–Expanded Detention at Armory Site (see component 1e) $3,459,700 Component 7c–Detention at 9th Avenue/Washburn Street (see component 1c) $1,812,300 Component 7d-Storm Sewer System Improvements from Landmark Plaza to Tippler 3-foot by 5-foot RCP Box (850 lf) $255,000 Two 3-foot by 5-foot RCP Box AEW $10,000 27-inch RCP and 27-inch AEW 4,200 100-Year Inlet Capacity on Westfield Street 7,200 Storm Sewer Junction Chamber and High Capacity Inlet at Landmark Plaza $27,000 Ditch Regrading and Restoration $21,300 34-inch orifice plate $1,000 Curb and Gutter and Asphalt Restoration $1,300 Subtotal $327,000 Engineering and Contingency (25%) $81,800 Total $408,800 Grand Total $7,463,900 Note: Costs do not include utility conflict resolution, if any. The City should survey the existing earhen hill at the expanded Armory detention basin site and add the cost for removal to the cost of Alternative 7. Table 4.08-1 Alternative 7–Opinion of Probable Cost The Opinion of Probable Costs for the alternative outlined above is shown in Table 4.08-1. The benefit of this alternative is shown in Table 4.08-2. Modeling indicates this alternative would meet the desirable 2 feet of freeboard at the eastern Landmark Plaza building for both the 100-year, 2-hour and 12-hour duration storm events. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been eliminated according to the model (internal flooding of Landmark Plaza inlets notwithstanding). Under a 100-year storm event, there is still some surface ponding at the parking lot inlets at Landmark Plaza and at the low point east of the eastern Landmark Plaza building. This alternative is ranked 6th for watershed-wide benefit. At the expanded Tippler Pond, our model shows that the overland flow route would not be operating under the 100-year, 2-hour duration storm but would pass about 1.5 cfs through the overland flow route in the 100-year, 12-hour duration storm which allows for 2.26 feet of freeboard to the Tippler Administration building. Along the Landmark Plaza ditch, Alternative 7 provides an approximate 100-year capacity in the five ditch segments as well as for the culvert P-LP-1. The model shows that these five ditch segments and culvert would not reach elevations that would enter the first floor elevation of the southern Landmark Plaza building or the movie theater building after implementation of this alternative. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-24 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre-feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 3.23 0 N/A 10-year, 12-hour w/alternative 3.55 0 N/A 100-year, 2-hour w/alternative 2.33 0.05 Yes 100-year, 12-hour w/alternative 2.94 0.01 Yes June 11, 2004 w/ alternative (Existing Conditions) 3.55 0 N/A Average = 5 4 6 Table 4.08-2 Future Conditions Effects–Alternative 7 For this alternative, the City would be able to claim TSS reductions for the expanded Tippler and W. 9th Avenue/Washburn Street ponds. Depending on the final arrangement of the expanded Armory pond (if the pond can be expanded to the north and incorporate the existing ditch thus accepting all flows, not allowing the 2-year flow to divert the pond through the existing ditch), the City may also be able to claim TSS reductions to help meet the Phase 2 DNR requirements of 20 percent and 40 percent TSS by March 10, 2008, and March 10, 2013, respectively 4.09 ALTERNATIVE 8 Alternative 8 includes the following mix of project components: 1. Expanded Detention (20.8 acre-feet) at Tippler Junior High property (Figure 4.04-2). This cost has been reduced by $678,700 from the full cost shown in Alternative 7 because of the nonrealization of full pond storage volume (20.78 acre-feet instead of 50 acre-feet) due to elimination of the diversion across USH 41 at Landmark Plaza. 2. Expanded Detention (40.9 acre-feet) at the Armory site and upstream pipe upsizing (flow diversion modification as discussed in Alternative 3 and implemented in Alternative 1 (Component 1e) to feed the basin (Figure 4.02-1E). 3. Detention (16.5 acre-feet) at W. 9th Avenue/Washburn Street (Figure 4.02-1C)–This cost has been reduced by $674,400 from the full cost shown in Alternative 1 because of the nonrealization of full pond storage volume (16.5 acre-feet instead of 31.2 acre-feet) due to diversion of substantial flows formerly draining to this pond to the Expanded Westhaven Golf Course Detention Pond. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-25 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Component 8a–Expanded Detention at Tippler Junior High property (see component 7a) 1,104,400 Component 8b–Expanded Detention at Armory Site (see component 1e) $3,459,700 Component 8c–Detention at 9th Avenue/Washburn Street (see component 1c) $1,137,900 Component 8d–Expanded Westhaven Golf Course Detention (see component 3d) $8,274,600 Component 8e–Storm Sewer Upsizing from Landmark Plaza to Tippler (see component 6d) $174,100 Component 8f 00-year Storm Sewer in DOT ROW downstream of Witzel (see component 6e) $1,880,100 Total $16,030,800 Note: Costs do not include utility conflict resolution, if any. Table 4.09-1 Alternative 8–Opinion of Probable Cost 4. 120 acre-feet of detention at the Expanded Westhaven Golf Course Detention Pond (Figure 4.04-3). 5. Storm Sewer Upsizing from Landmark Plaza to Tippler (Figure 4.04-2). 6. Construction of new 100-Year Storm Sewer in DOT ROW to the north of Diversion Point 2 along Washburn Street to allow for the elimination of Diversion Point 2 crossing USH 41 west of Landmark Plaza (Figures 4.04-1 and 4.04-2). The Opinion of Probable Costs for the alternative outlined above is shown in Table 4.09-1. The benefit of this alternative is shown in Table 4.09-2. Modeling indicates this alternative would meet the desirable 2 feet of freeboard at the eastern Landmark Plaza building for the 100-year, 2-hour duration storm event. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been eliminated according to the model (internal flooding of Landmark Plaza inlets notwithstanding). Under a 100-year storm event, there is still some surface ponding at the parking lot inlets at Landmark Plaza and at the low point east of the eastern Landmark Plaza building. This alternative is ranked third for watershed-wide benefit and first for benefit at Landmark Plaza. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-26 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre-feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 3.24 0 N/A 10-year, 12-hour w/alternative 3.55 0 N/A 100-year, 2-hour w/alternative 2.02 0.13 Yes 100-year, 12-hour w/alternative 3.54 0 Yes June 11, 2004 w/ alternative (Existing Conditions) 3.55 0 N/A Average = 1 1 1 Table 4.09-2 Future Conditions Effects–Alternative 8 For this alternative, the City would be able to claim TSS reductions for the expanded Tippler and W. 9th Avenue/Washburn Street ponds. Depending on the final arrangement of the expanded Armory pond (if the pond can be expanded to the north and incorporate the existing ditch thus accepting all flows, not allowing the 2-year flow to divert the pond through the existing ditch), the City may also be able to claim TSS reductions to help meet the Phase 2 DNR requirements of 20 percent and 40 percent TSS by March 10, 2008, and March 10, 2013, respectively. 4.10 ALTERNATIVE 9 Alternative 9 includes the following mix of project components as a described below. 1. Expanded Detention (42.7 acre-feet) at Tippler Junior High property (Figure 4.04-2). 2. Expanded Detention (38.5 acre-feet) at the Armory site and upstream pipe upsizing (flow diversion modification as discussed in Alternative 3 and implemented in Alternative 1 (Component 1e) to feed the basin (Figure 4.02-1E). 3. 16.5 acre-feet of detention at W. 9th Avenue/Washburn Street (Figure 4.02-1C)–This cost has been reduced by $674,400 from the full cost shown in Alternative 1 because of the nonrealization of full pond storage volume (16.5 acre-feet instead of 31.2 acre-feet) because of diversion of substantial flows formerly draining to this pond to the Expanded Westhaven Golf Course Detention Pond. 4. 120.2 acre-feet of detention at the Expanded Westhaven Golf Course Detention Pond (Figure 4.04-3). 5. Storm Sewer Upsizing from Landmark Plaza to Tippler (Figure 4.04-2). City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-27 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre-feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 3.24 0 N/A 10-year, 12-hour w/alternative 3.36 0 N/A 100-year, 2-hour w/alternative 2.02 0.13 Yes 100-year, 12-hour w/alternative 2.82 0 Yes June 11, 2004 w/ alternative (Existing Conditions) 3.18 0 N/A Average = 3 6 2 Table 4.10-2 Future Conditions Effects–Alternative 9 Item Capital Cost Component 9a–Expanded Detention at Tippler Junior High property (see component 7a) 1,783,100 Component 9b–Expanded Detention at Armory Site (see component 1e) $3,459,700 Component 9c–Detention at 9th Avenue/Washburn Street (see component 1c) $1,137,900 Component 9d-Expanded Westhaven Golf Course Detention (see component 3d) $8,274,600 Component 9e–Storm Sewer Upsizing from Landmark Plaza to Tippler (see component 7d) $176,300 Total $14,831,600 Note: Costs do not include utility conflict resolution, if any. Table 4.10-1 Alternative 9–Opinion of Probable Cost The Opinion of Probable Costs for the alternative outlined above is shown in Table 4.10-1. The benefit of this alternative is shown in Table 4.10-2. Modeling indicates this alternative would meet the desirable 2 feet of freeboard at the eastern Landmark Plaza building for the 100-year, 2-hour duration storm event. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been eliminated according to the model (internal flooding of Landmark Plaza inlets notwithstanding). Under a 100-year storm event, there is still some surface ponding at the parking lot inlets at Landmark Plaza and at the low point east of the eastern Landmark Plaza building. This alternative is ranked 2nd for watershed-wide benefit. This is due to the maximum amount of storage being provided that helps to reduce flooding watershed-wide. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-28 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 For this alternative, the City would be able to claim TSS reductions for the expanded Tippler, Westhaven Golf Course, and W. 9th Avenue/Washburn Street ponds. Depending on the final arrangement of the expanded Armory pond (if the pond can be expanded to the north and incorporate the existing ditch thus accepting all flows, not allowing the 2-year flow to divert the pond through the existing ditch), the City may also be able to claim TSS reductions to help meet the Phase 2 DNR requirements of 20 percent and 40 percent TSS by March 10, 2008, and March 10, 2013, respectively. 4.11 ALTERNATIVE 10 Alternative 10 includes the following mix of project components: 1. Expanded Detention (20.8 acre-feet) at Tippler Junior High property (Figure 4.04-2). This cost has been reduced by $678,700 from the full cost shown in Alternative 7 because of the nonrealization of full pond storage volume (20.78 acre-feet instead of 50 acre-feet) due to elimination of the diversion across USH 41 at Landmark Plaza. 2. Expanded Detention (40.8 acre-feet) at the Armory site and upstream pipe upsizing (flow diversion modification as discussed in Alternative 3 and implemented in Alternative 1 (Component 1e) to feed the basin (Figure 4.02-1E). 3. No Detention at W. 9th Avenue/Washburn Street (Figure 4.02-1C). 4. 120.4 acre-feet of detention at the Expanded Westhaven Golf Course Detention Pond (Figure 4.04-3). 5. Storm Sewer Upsizing from Landmark Plaza to Tippler (Figure 4.04-2). 6. Construction of new 100-Year Storm Sewer in DOT ROW to the north of Diversion Point 2 along Washburn Avenue to allow for the elimination of Diversion Point 2 crossing USH 41 west of Landmark Plaza (Figures 4.04-1 and 4.04-2). City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-29 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Component 10a–Expanded Detention at Tippler Junior High property (see component 7a) 1,104,400 Component 10b–Expanded Detention at Armory Site (see component 1e) $3,459,700 Component 10c–Expanded Westhaven Golf Course Detention (see component 3d) $8,274,600 Component 10d–Storm Sewer Upsizing from Landmark Plaza to Tippler (see component 6d) $174,100 Component 10e–100-year Storm Sewer in DOT ROW downstream of Witzel (see component 6e) $1,880,100 Total $14,892,900 Note: Costs do not include utility conflict resolution, if any. Table 4.11-1 Alternative 10–Opinion of Probable Cost Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre-feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 3.24 0 N/A 10-year, 12-hour w/alternative 3.55 0 N/A 100-year, 2-hour w/alternative 2.02 0.13 Yes 100-year, 12-hour w/alternative 3.54 0 Yes June 11, 2004 w/ alternative (Existing Conditions) 3.55 0 N/A Average = 2 2 4 Table 4.11-2 Future Conditions Effects–Alternative 10 The Opinion of Probable Costs for the alternative outlined above is shown in Table 4.11-1. The benefit of this alternative is shown in Table 4.11-2. Modeling indicates this alternative would meet the desirable 2 feet of freeboard at the eastern Landmark Plaza building for the 100-year, 2-hour duration storm event. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been eliminated according to the model (internal flooding of Landmark Plaza inlets notwithstanding). Under a 100-year storm event, there is still some surface ponding at the parking lot inlets at Landmark Plaza and at the low point east of the eastern Landmark Plaza building. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-30 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Item Capital Cost Component 11a–Expanded Detention at Tippler Junior High property (see component 7a) 1,783,100 Component 11b–Expanded Detention at Armory Site (see component 1e) $3,459,700 Component 11c-Expanded Westhaven Golf Course Detention (see component 3d) $8,274,600 Component 11d-Storm Sewer Upsizing from Landmark Plaza to Tippler (see component 7d) $176,300 Total $13,693,700 Note: Costs do not include utility conflict resolution, if any. Table 4.12-1 Alternative 11–Opinion of Probable Cost For this alternative, the City would be able to claim TSS reductions for the expanded Tippler and Westhaven Golf Course ponds. Depending on the final arrangement of the expanded Armory pond (if the pond can be expanded to the north and incorporate the existing ditch thus accepting all flows, not allowing the 2-year flow to divert the pond through the existing ditch), the City may also be able to claim TSS reductions to help meet the Phase 2 DNR requirements of 20 percent and 40 percent TSS by March 10, 2008, and March 10, 2013, respectively. 4.12 ALTERNATIVE 11 Alternative 11 includes the following mix of project components: 1. Expanded Detention (46.4 acre-feet) at Tippler Junior High property (Figure 4.04-2). 2. Expanded Detention (38.6 acre-feet) at the Armory site and upstream pipe upsizing (flow diversion modification as discussed in Alternative 3 and implemented in Alternative 1 (Component 1e) to feed the basin (Figure 4.02-1E). 3. 120.2 acre-feet of detention at the Expanded Westhaven Golf Course Detention Pond (Figure 4.04-3). 4. Storm Sewer Upsizing from Landmark Plaza to Tippler (Figure 4.04-2). The Opinion of Probable Costs for the alternative outlined above is shown in Table 4.12-1. The benefit of this alternative is shown in Table 4.12-2. Modeling indicates this alternative would meet the desirable 2 feet of freeboard at the eastern Landmark Plaza building for the 100-year, 2-hour duration storm event. Had this infrastructure been in place during the June 10/11, 2004, storm event, the flooding volume would have been eliminated according to the model (internal flooding of Landmark Plaza inlets notwithstanding). Under 100-year storm event, there is still some surface ponding at the parking lot inlets at Landmark Plaza and at the low point east of the eastern Landmark Plaza building. This alternative is ranked fifth for watershed-wide benefit. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-31 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Location Freeboard at Landmark Plaza (feet) Flooding Volume at Landmark Plaza (acre- feet) Meets Freeboard Criteria at Landmark Plaza (out of 11) Alternative Ranking for Flood Reduction at Landmark Plaza (out of 11) Alternative Ranking for Watershed- Wide Benefit 10-year, 2-hour w/alternative 3.24 0 N/A 10-year, 12-hour w/alternative 3.29 0 N/A 100-year, 2-hour w/alternative 2.02 0.13 Yes 100-year, 12-hour w/alternative 2.46 0.03 Yes June 11, 2004 w/ alternative (Existing Conditions) 3.14 0 N/A Average = 7 7 5 Table 4.12-2 Future Conditions Effects–Alternative 11 For this alternative, the City would be able to claim TSS reductions for the expanded Tippler and Westhaven Golf Course ponds. Depending on the final arrangement of the expanded Armory pond (if the pond can be expanded to the north and incorporate the existing ditch thus accepting all flows, not allowing the 2-year flow to divert the pond through the existing ditch), the City may also be able to claim TSS reductions to help meet the Phase 2 DNR requirements of 20 percent and 40 percent TSS by March 10, 2008, and March 10, 2013, respectively. 4.13 SUMMARY OF ALTERNATIVES AND ALTERNATIVES ANALYSIS Table 4.13-1 summarizes the alternatives discussed in Sections 4.02 through 4.12. Table 4.13-2 provides the ranking data and Table 4.13-3 provides the ranking criteria. To arrive at a recommendation after assessment of these eleven alternatives, we have used the following criteria. Select the lowest cost alternative that meets the following criteria. 1. Meets Landmark Plaza Flooding Criteria (2 feet or greater freeboard = Alternatives 3, 6, 7, 8, 9, 10, 11; and 1.5 to 2 feet freeboard = Alternative 2). 2. Meets Tippler Flooding Criteria (2 feet or greater freeboard = Alternatives 3, 6, 7, 8, 9, 10, and 11; 1.5 to 2 feet freeboard = Alternative 2). 3. Is in the top six for watershed-wide benefit ranking (Alternatives 3, 7,8, 9, 10 and 11) 4. Keeps the increased peak discharge at USH 41 to a minimum (Alternatives 7, 9 and 11). See Table 4.13-4. 5. Maximizes use of the ponds considered under these alternatives. See Table 4.13-5. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-32 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 Alt. Existing Conditions 100- year (2hr /12hr) Future Conditions 100- year (2hr/12hr) Future Conditions 100-yr, 2hr peak flow increase Future Conditions 100-yr, 12hr peak flow increase Rank 2 134/153 140/152 6 -1 4 3 134/153 186/156 52 3 5 6 134/153 21 82 30 7 7 134/153 14 7 -26 2 8 134/153 22 87 28 6 9 134/153 14 7 -29 1 10 134/153 22 88 43 8 11 134/153 14 8 -24 3 Table 4.13-4 Least Amount of Increase in 100-Year, 2-Hour and 12-Hour Duration Flow Rates at Sawyer Creek/USH 41 Outfall Ranking Alt. (acre-feet) Future Conditions 100-yr, 12hr Watershed- Wide Storage Usage Rank (acre-feet) Future Conditions 100-yr, 12hr Usage of Tippler Pond (acre-feet) Future Conditions 100-year 12hr Usage of 9th Avenue/Wash burn Street Pond (acre-feet) Future Conditions 100-yr, 12hr Usage of Armory Pond (acre-feet) Total Usage of 3 Ponds Total Usage of 3 Ponds Rank 2 22.3 8 4.3 N/A 3.0 7.3 8 3 214.2 2 30.8 16.5 40.9 88.2 4 6 116.4 7 20.8 31.2 50.5 102.5 2 7 140.3 6 44.7 31.1 50.7 126.5 1 8 204.2 4 20.8 16.5 40.9 78.2 6 9 223.6 1 42.7 16.5 38.5 97.7 3 10 188.1 5 20.8 N/A 40.8 61.6 7 11 211.1 3 46.4 N/A 38.6 85.0 5 Table 4.13-5 Maximizes Use of Storage in Watershed For the purposes of this assessment, Alternatives 1, 4, and 5 are not feasible because they do not meet the Landmark Plaza freeboard criteria, so they are not included in Table 4.13-4 or Table 4.13-5. Also, Alternatives 3 and 8 through 11 may not be economically feasible. The lowest cost alternative meeting these criteria is Alternative 7. However, we feel that after implementation of the components of Alterntative 7, the City should consider providing 120 acre-feet or more of detention at the Westhaven Golf Course or upstream of W. 20th Avenue to deal with persistent flooding problems along W. Washburn Street between W. 20th Avenue and W. 9th Avenue and southeast of Allerton Drive. The high cost to get stormwater to and build detention at the Westhaven Golf Course would be offset by the benefit in reducing actual flood damage costs and is a deterrent to providing this 120 acre-feet of detention. For example, for $8,000,000 (the cost of the Expanded Golf Course Detention Pond considered in Alternatives 3, and 8-11), the City could acquire 40 properties that flood at $200,000 each. Detention upstream of W. 20th Avenue may be more readily accessible, thus decreasing the cost of providing this detention. Ci t y o f O s h k o s h , W i s c o n s i n No r t h B r a n c h C a m p b e l l C r e e k S t o r m w a t e r M a n a g e m e n t P l a n Se c t i o n 4 – A l t e r n a t i v e A n a l y s i s Pr e p a r e d b y S t r a n d A s s o c i a t e s , I n c . ® Pa g e 1 o f 1 JH L : p l l \ S : \ @ S A I \ 3 5 1 - - 4 0 0 \ 3 8 2 \ 0 2 1 \ W r d \ R e p o r t - O s hk o s h C a m p b e l l C r e e k S M P \ T a b l e 4 . 1 3 - 1 . d o c \ 0 5 2 5 0 6 TA B L E 4 . 1 3 - 1 SU M M A R Y O F A L T E R N A T I V E S ( I N C L U D I N G L A N D A C Q U I S I T I O N C O S T S A N D 2 5 P E R C E N T E N G I N E E R I N G A N D C O N T I N G E N C Y ) Al t . Al t e r n a t i v e D e s c r i p t i o n La n d m a r k P l a z a Be n e f i t R a n k Wa t e r s h e d - W i d e Be n e f i t R a n k Av g . Ra n k Me e t s L a n d m a r k Pl a z a C r i t e r i a Op i n i o n o f Pr o b a b l e C o s t 1 D e t e n t i o n a t F o u r L o c at i o n s 9 8 8 N o $ 7 , 3 9 4 , 2 0 0 2 I n c r e a s e C o n v e y a n c e C a p a c i t y i n N o r t h B r a n c h S y s t e m 8 1 1 9 Y e s $ 2 , 8 9 9 , 0 0 0 3 F l o w D i v e r s i o n M o d i f i c a t i o n 5 3 4 Y e s $ 1 6 , 2 1 3 , 6 0 0 4 S t o r m w a t e r P u m p S t a t i o n a t D o w n s t r e a m E n d o f C a m p b e l l C r e e k 1 1 1 0 1 1 N o $ 2 , 6 8 2 , 6 0 0 5 S i n g l e M i x o f A l t e r n a t i v e s 1 0 9 1 0 N o $ 5 , 5 8 1 , 5 0 0 6 A l t e r n a t i v e 6 3 7 6 Y e s $ 8 , 4 3 0 , 6 0 0 7 A l t e r n a t i v e 7 4 6 5 Y e s $ 7 , 4 6 3 , 9 0 0 8 A l t e r n a t i v e 8 1 1 1 Y e s $ 1 6 , 0 3 0 , 8 0 0 9 A l t e r n a t i v e 9 6 2 3 Y e s $ 1 4 , 8 3 1 , 6 0 0 10 A l t e r n a t i v e 1 0 2 4 2 Y e s $ 1 4 , 8 9 2 , 9 0 0 11 A l t e r n a t i v e 1 1 7 5 7 Y e s $ 1 3 , 6 9 3 , 7 0 0 No t e : C o m p o n e n t 2 c ( $ 8 2 , 4 0 0 ) w o u l d b e a L a n d m a r k P l a z a p r o p e r t y o w n e r co s t b u t i s i n c l u d e d i n t h e c o s t s f o r A l t . 2 i n t h i s t a b l e. Al t e r n a t i v e 1 2 3 4 5 6 7 8 9 10 11 De t e n t i o n a t T i p p l e r J u n i o r H i g h Y e s N o N o N o Y e s N o N o N o N o N o N o Ex p a n d e d D e t e n t i o n a t T i p p l e r J u n i o r H i g h N o N o Y e s N o N o Y e s Y e s Y e s Y e s Y e s Y e s La r g e r P i p e f r o m L a n d m a r k P l a z a t o T i p p l e r N o Y e s Y e s N o N o Y e s Y e s Y e s Y e s Y e s Y e s De t e n t i o n S o u t h o f L a n d m a r k P l a z a Y e s N o N o N o Y e s N o N o N o N o N o N o Ex i s t i n g D e t e n t i o n a t A r m o r y No Y e s N o Y e s N o N o N o N o N o N o N o Ex p a n d e d D e t e n t i o n a t A r m o r y Y e s N o Y e s N o Y e s Y e s Y e s Y e s Y e s Y e s Y e s De t e n t i o n a t 9 t h / W a s h b u r n Ye s N o Y e s N o N o Y e s Y e s Y e s Y e s N o N o Ex i s t i n g G o l f C o u r s e D e t e n t i o n Y e s Y e s N o Y e s Y e s Y e s Y e s N o N o N o N o Ex p a n d e d G o l f C o u r s e D e t e n t i o n N o N o Y e s N o N o N o N o Y e s Y e s Y e s Y e s Pu m p S t a t i o n a t C a m p b e l l C r e e k O u t f a l l N o N o N o Y e s N o N o N o N o N o N o N o Di v e r s i o n P i p e u n d e r H W Y 4 1 a t L a n d m a r k P l a z a Y e s Y e s Y e s Y e s Y e s N o Y e s N o Y e s N o Y e s 10 0 - y e a r s t o r m s e w e r i n D O T R O W f r o m L a n d m ar k P l a z a D i v e r s i o n t o S a w y e r C r e e k a l o n g US H 4 1 No N o Y e s N o N o Y e s N o Y e s N o Y e s N o Ex i s t i n g W a l - M a r t D e t e n t i o n Ye s Y e s Y e s Y e s Y e s Y e s Y e s Y e s Y e s Y e s Y e s In c r e a s e C o n v e y a n c e C a p a c i t y f r o m L a n d m a r k P l a z a t o C a m p b e l l Cr e e k O u t f a l l N o Y e s N o N o N o N o N o N o N o N o N o In c r e a s e I n t e r n a l C o n v e y a n c e C a p a c i t y a t L a n d m a r k P l a z a N o Y e s N o N o N o N o N o N o N o N o N o Mo d i f i e d D i v e r s i o n P i p e u n d e r H W Y 4 1 a t L a n d m a r k P l a z a N o N o Y e s N o N o N o N o N o N o N o N o City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Engineering Analysis Prepared by Strand Associates, Inc.® Page 1 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 4.13-2 new.doc\052606 TABLE 4.13-2 SUMMARY OF EFFECTS–RANKING DATA (all future conditions except June 11, 2004 which is 20% higher RCNs with Existing RCNs)100-Year 100-Year 100-Year 100-Year 100-Year 100-Year Max High Flooding Acceptable High Flooding Acceptable High Flooding Acceptable High Flooding Acceptable High Flooding Acceptable High Flooding Acceptable High US Peak High US Peak High Peak High Peak High US Peak High US Peak High Volume High US Peak High US Peak Water El. Volume Flooding Water El. Volume Flooding Water El. Volume Flooding Water El. Volume Flooding Water El. Volume Flooding Water El. Volume Flooding Water El. Flow Rate Water El. Flow Rate Water El. Flow Rate Water El. Flow Rate Water El. Flow Rate Water El. Flow Rate Water El. Exiting Water El. Flow Rate Water El. Flow Rate Location (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (Feet) (cfs) (Feet) (cfs) (Feet) (cfs) (Feet) (cfs) (Feet) (cfs) (Feet) (cfs) (Feet) (ac-ft) (Feet) (cfs) (Feet) (cfs) Alternative 1 (All Detention) 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 760.33 0.16 760.75 755.48 6.33 759.81 766.37 2.43 770 767.56 21.35 771 772.99 11.26 777 777.96 1.68 780 748.64 139 747.55 236 752.55 74 749.57 49 752.07 32.3 753.09 150 780.5 1.67 764.32 39.24 764.25 39 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year 12 Hour w/ Alternative 760.16 0.09 760.75 758.10 16.94 759.81 766.89 3.11 770 768.67 31.26 771 773.99 17.22 777 778.77 2.94 780 748.4 134 747.55 194 752.55 73 749.57 37 751.84 27.75 752.93 129 780.58 4.3 764.69 38.96 764.61 39 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 761.71 5.28 760.75 759.27 23.33 759.81 768.35 5.01 770 769.31 37.08 771 774.48 20.2 777 779.5 4.96 780 749.75 172 748.38 411 755.37 139 751.04 94 752.54 84 753.63 247 781 19.9 764.81 63.24 764.67 63 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year 12 Hour w/ Alternative 762.32 10.45 760.75 759.42 24.46 759.81 768.94 5.77 770 770.74 50.64 771 776.21 31.16 777 780 8.02 780 749.35 168 747.77 284 755.37 122 751.04 71 752.32 52 753.48 198 781.05 33 764.81 63.24 764.99 54 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 20004 w/ Alternative 761.92 7.17 760.75 759.38 24.15 759.81 768.41 5.08 770 769.95 43 771 775.96 29.6 777 779.97 7.84 780 748.76 162 747.66 245 754.33 102 750.49 53 752.23 42 753.36 174 780.95 21 765.11 48.89 764.98 49 1 Alternative 2 (Increased Conveyance) 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 758.96 0.00 760.75 757.19 0.00 759.81 766.61 2.75 770 767.79 0.72 770.31 N/A 0 N/A 778.04 1.79 780 749.25 202 747.67 267 752.55 89 749.57 49 752.15 95 753.13 156 780.78 9.51 764.96 49.8 764.81 50 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 758.84 0.00 760.75 757.23 0.00 759.81 767.55 3.96 770 768.51 1.25 770.31 N/A 0 N/A 779.04 3.41 780 749.5 215 747.82 295 752.55 113 749.57 59 752.65 143 753.26 174 781.01 27.2 765.09 51.36 764.93 52 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 760.58 0.34 760.75 759.21 2.56 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A 0 N/A 779.5 4.95 780 750.83 217 748.44 424 755.37 140 751.04 94 753.22 239 753.64 246 781.1 41 765.57 56.78 765.37 57 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year, 12 hour w/Alternative 760.77 0.64 760.75 759.51 4.34 759.81 770.31 6.91 770 770.72 2.99 770.31 N/A 0 N/A 780.13 8.08 780 750.7 220 748.39 414 755.37 152 751.04 95 753.42 241 753.8 260 781.22 77 765.79 67.95 765.51 68 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternative 759.18 0.00 760.75 757.26 0.00 759.81 768.73 5.54 770 769.78 2.28 770.31 N/A 0 N/A 779.99 8.03 780 749.47 215 747.79 288 754.33 122 750.49 53 752.77 144 753.39 176 781.12 38.3 765.27 51.74 765.10 52 2 Alternative 3 - Modified Diversion 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 759.04 0.00 760.75 754.41 7.26 759.81 766.45 2.54 770 767.16 17.93 771 771.98 5.43 777 776.95 33.17 780 748.61 137.69 747.55 232.77 752.55 102.71 749.57 49.28 751.69 24.31 753.09 154.02 779.69 0.09 763.42 19.73 763.38 22 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 758.73 0.00 760.75 754.99 11.24 759.81 766.85 3.06 770 767.73 22.85 771 772.45 8.12 777 777.93 55.99 780 748.38 130.96 747.55 191.64 752.55 80.49 749.57 36.67 751.66 24.03 752.92 126.95 779.53 0 764.56 18.94 764.45 20 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 760.26 0.13 760.75 755.99 19.00 759.81 768.47 5.16 770 768.62 30.81 771 773.36 13.43 777 778.16 61.41 780 750.2 160.99 748.35 404.59 755.37 185.9 751.04 94.35 752.23 42.57 753.63 246.59 780.64 5.35 765.54 25.19 765.48 31 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year, 12 hour w/Alternative 758.92 0.00 760.75 757.47 30.87 759.81 768.91 5.73 770 769.72 40.88 771 773.87 16.5 777 780.6 120.18 780 749.33 161.85 747.76 282.86 755.37 156.26 751.04 71.02 752.11 31.7 753.48 200.84 780.72 7.41 763.7 22.82 763.69 29 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternative 758.84 0 760.75 756.65 24.22 759.81 768.29 4.93 770 768.77 32.15 771 773.61 14.88 777 779.26 87.59 780 748.74 154.9 747.66 241.76 754.33 120.63 750.49 52.85 752.07 29.75 753.35 173.15 780.36 2.02 763.55 21.28 763.51 25 3 Alternative 4 (Pump Station) 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 761.76 5.67 760.75 759.71 5.77 759.81 766.74 2.91 770 767.79 0.72 770.31 N/A 0 N/A 778.04 1.8 780 747.3 164 N/A 286 752.55 73 749.57 49 752.3 55 753.09 159 780.78 6.81 765.24 49.73 765.08 50 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 762.35 11.85 760.75 760.05 8.51 759.81 767.42 3.79 770 768.21 1.01 770.31 N/A 0 N/A 778.81 3.02 780 747.21 165 N/A 272 752.55 75 749.57 37 752.62 85.5 753.03 148 780.94 15.55 765.54 55.12 765.35 56 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 762.43 12.82 760.75 760.07 8.70 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A 0 N/A 779.5 4.97 780 748.09 178 N/A 416 755.37 140 751.04 94 752.7 101 753.62 247 781.09 33.83 765.6 56.24 765.41 56 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year, 12 hour w/Alternative 762.58 14.71 760.75 760.48 12.76 759.81 769.22 6.11 770 769.8 2.31 770.31 N/A 0 N/A 780 8.08 780 747.5 183 N/A 348 755.37 131 751.04 71 753.37 161 753.48 206 781.21 59.8 765.49 54.1 765.31 54 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternative 762.53 14.06 760.75 760.36 11.46 759.81 768.77 5.55 770 769.78 2.28 770.31 N/A 0 N/A 779.99 8.03 780 747.33 179 N/A 302 754.33 123 750.49 53 753.31 140 753.36 179 781.12 38.2 765.3 50.57 765.14 51 4 Alternative 5 (Single Mix of Alt.) 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 760.35 0.17 760.75 756.28 9.46 759.81 766.76 2.94 770 767.57 21.48 771 N/A 0 N/A 778.02 1.77 780 748.64 139 747.55 236 752.55 88 749.57 49 752.07 32 753.09 150 780.5 1.68 765.02 50.09 764.93 50 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 760.60 0.37 760.75 758.55 18.95 759.81 767.28 3.61 770 768.67 31.28 771 N/A 0 N/A 778.79 2.98 780 748.4 134 747.55 194 752.55 86 749.57 37 751.87 28 752.93 129 780.58 4.3 765.2 50.52 765.11 50 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 761.72 5.34 760.75 759.29 23.45 759.81 768.4 5.08 770 769.19 36 771 N/A 0 N/A 779.51 4.99 780 750.36 172 748.38 411 755.37 140 751.04 94 752.54 84 753.63 245 780.99 19.9 765.28 67.83 765.18 68 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year 12 Hour w/Alternatives 762.30 11.25 760.75 759.43 24.49 759.81 769.19 6.08 770 770.55 48.83 771 N/A 0 N/A 780 8.06 780 749.35 168 747.77 285 755.37 129 751.04 71 752.32 53 753.48 199 781.05 33.3 765.53 60.65 765.37 61 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternatives 762.12 9.15 760.75 759.37 24.09 759.81 768.74 5.51 770 769.95 43.05 771 N/A 0 N/A 779.98 7.89 780 748.76 162 747.66 245 754.33 125 750.49 53 752.28 48 753.36 174 780.95 20.6 765.42 51.21 765.29 51 5 Alternative 6 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 759.05 0.00 760.75 754.11 5.53 759.81 766.43 2.51 770 767.55 21.29 771 772.99 11.23 777 777.96 1.68 780 748.61 137.18 747.55 232.69 752.55 109.26 749.57 49.29 751.68 24.27 753.09 152.74 780.5 3.17 762.42 0 762.41 7 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 758.73 0.00 760.75 754.23 6.19 759.81 767 3.25 770 768.66 31.11 771 773.99 17.22 777 778.77 2.95 780 748.38 131.17 747.55 191.97 752.55 110.12 749.57 36.67 751.48 22.89 752.93 129.11 780.58 4.32 762 0 762.00 3 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 760.26 0.13 760.75 755.65 16.25 759.81 768.42 5.1 770 769.29 36.86 771 774.46 20.11 777 779.5 4.93 780 750.2 160.91 748.35 404.82 755.37 216.15 751.04 94.36 752.22 42.57 753.63 245.76 780.99 24.5 763.17 0 763.17 18 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year, 12 hour w/Alternative 758.74 0.00 760.75 756.22 20.79 759.81 769.07 5.94 770 770.72 50.48 759.81 776.21 31.16 777 779.99 8.01 780 749.32 159.2 747.76 282.75 755.37 183.06 751.04 71.05 752.1 30.8 753.48 199.67 781.05 33.33 762.4 0 762.40 7 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternative 758.73 0.00 760.75 755.70 16.67 759.81 768.55 5.27 770 769.95 43.08 771 775.96 25.58 777 779.97 7.84 780 748.73 152.99 747.66 241.49 754.33 149.33 750.49 52.85 752.03 28.09 753.36 176.49 780.95 20.58 762.12 0 762.11 4 6 AEW-11STR 10Storm Sewer ConfluenceCampbell Creek Cunette Outfall Westfield OutfallHWY 41 Outfall 06-1282Campbell Creek Pipe Outfall Storm Sewer ConfluencLandmark Plaza Tippler Jr. High Armory Pond 9th/Washburn Pond New Westhaven Golf Course PondExisting Walmart Pond City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Engineering Analysis Prepared by Strand Associates, Inc.® Page 2 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 4.13-2 new.doc\052606 TABLE 4.13-2 (CONTINUED) SUMMARY OF EFFECTS–RANKING DATA (all future conditions except June 11, 2004 which is 20% higher RCNs with Existing RCNs)100-Year 100-Year 100-Year 100-Year 100-Year 100-Year Max High Flooding Acceptable High Flooding Acceptable High Flooding Acceptable High Flooding Acceptable High Flooding Acceptable High Flooding Acceptable High US Peak High US Peak High Peak High Peak High US Peak High US Peak High Volume High US Peak High US Peak Water El. Volume Flooding Water El. Volume Flooding Water El. Volume Flooding Water El. Volume Flooding Water El. Volume Flooding Water El. Volume Flooding Water El. Flow Rate Water El. Flow Rate Water El. Flow Rate Water El. Flow Rate Water El. Flow Rate Water El. Flow Rate Water El. Exiting Water El. Flow Rate Water El. Flow Rate Location (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (feet) (ac-ft) Elevation (Feet) (cfs) (Feet) (cfs) (Feet) (cfs) (Feet) (cfs) (Feet) (cfs) (Feet) (cfs) (Feet) (ac-ft) (Feet) (cfs) (Feet) (cfs) Alternative 7 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 759.05 0.00 760.75 754.70 9.09 759.81 766.38 2.45 770 767.56 21.39 771 772.99 11.29 777 777.96 1.68 780 748.61 137.6 747.55 232.88 752.55 81.28 749.57 49.29 751.7 24.37 753.09 154.39 780.5 3.12 763.6 30.85 763.51 32 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 758.73 0.00 760.75 756.01 19.09 759.81 766.91 3.13 770 768.66 31.12 771 773.99 17.22 777 778.77 2.95 780 748.39 132.09 747.55 192.32 752.55 80.88 749.57 36.67 751.68 25.01 752.93 129.1 780.58 4.3 763.6 30.62 763.52 33 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 759.95 0.05 760.75 756.93 26.41 759.81 768.37 5.04 770 769.3 36.99 771 774.46 20.09 777 779.49 4.92 780 750.2 161.17 748.35 404.84 755.37 140.64 751.04 94.36 752.22 42.66 753.63 244.93 780.99 24.64 764.42 49.76 764.37 54 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year, 12 hour w/Alternative 759.34 0.01 760.75 759.05 44.66 759.81 768.97 5.81 770 770.74 50.71 771 776.21 31.14 777 779.99 8.01 780 749.33 164.89 747.76 283.14 755.37 126.78 751.04 71.1 752.13 32.79 753.48 199.2 781.05 33.35 764.04 42.44 764.02 48 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternative 758.73 0.00 760.75 758.15 36.60 759.81 768.44 5.12 770 769.94 43.02 771 775.96 29.55 777 779.97 7.83 780 748.74 157.48 747.66 243.05 754.33 110.89 750.49 52.85 752.1 31.46 753.36 176.88 780.95 20.54 763.99 39.64 763.88 42 7 Alternative 8 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 759.04 0.00 760.75 754.11 5.54 759.81 766.48 2.57 770 767.15 17.85 771 771.98 5.4 777 776.95 33.13 782 748.61 137.26 747.55 232.89 752.55 121.33 749.57 49.28 751.68 24.26 753.09 155.08 779.69 0.086 762.42 0 762.42 7 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 758.73 0.00 760.75 754.23 6.18 759.81 766.91 3.13 770 767.73 22.85 771 772.45 8.11 777 777.93 56.12 782 748.38 130.49 747.55 191.46 752.55 98.74 749.57 36.67 751.48 22.88 752.92 127.05 779.53 0 762 0 762.00 3 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 760.26 0.13 760.75 755.65 16.25 759.81 768.51 5.22 770 768.59 30.54 771 773.36 13.43 777 778.15 61.15 782 750.2 160.83 748.35 404.61 755.37 220.52 751.04 94.35 752.22 42.56 753.63 246.6 780.64 5.32 763.17 0 763.17 18 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year, 12 hour w/Alternative 758.74 0.00 760.75 756.22 20.78 759.81 768.97 5.81 770 769.71 40.83 771 773.87 16.49 777 780.61 120.3 759.81 749.32 159.16 747.76 282.68 755.37 181.3 751.04 71.02 752.1 30.8 753.48 200.84 780.72 7.42 762.4 0 762.40 7 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternative 758.73 0.00 760.75 755.70 16.65 759.81 768.36 5.02 770 768.77 32.11 771 773.61 14.89 777 779.29 88.39 782 748.73 152.66 747.66 240.9 754.33 141.63 750.49 52.85 752.03 28.08 753.35 173.14 780.37 2.03 762.11 0 762.11 4 8 Alternative 9 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 759.04 0.00 760.75 754.95 10.89 759.81 766.43 2.51 770 767.23 18.51 771 771.98 5.44 777 776.95 33.25 782 748.61 137.96 747.55 232.82 752.55 87.16 749.57 49.3 751.7 24.34 753.09 154.39 779.7 0.11 764.51 41.01 764.48 43 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 758.92 0.00 760.75 755.65 16.25 759.81 766.81 3 770 767.84 23.84 771 772.45 8.11 777 777.93 56.02 782 748.38 128.39 747.55 191.83 752.55 63.8 749.57 36.67 751.65 25 752.92 127.29 779.53 0 764.22 37.66 764.19 39 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 760.26 0.13 760.75 757.04 27.32 759.81 768.43 5.11 770 768.62 30.76 771 773.36 13.45 777 778.16 61.4 782 750.2 161.11 748.35 404.6 755.37 140.93 751.04 94.36 752.22 42.59 753.63 246.6 780.64 5.35 765.49 55.52 765.45 59 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year 12 Hour w/ Alternative 759.46 0.01 760.75 758.84 42.72 759.81 768.86 5.66 770 769.47 38.53 771 773.87 16.49 777 780.6 120.18 782 749.33 163.73 747.76 282.95 755.37 123.5 751.04 71.03 752.12 32.15 753.48 200.83 780.72 7.42 765.18 46.91 765.14 51 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternative 759.10 0.00 760.75 757.74 33.15 759.81 768.24 4.86 770 768.77 32.13 771 773.61 14.9 777 779.84 101.55 782 748.74 156.5 747.66 242.21 754.33 98.28 750.49 52.85 752.09 30.82 753.35 173.21 780.37 2.03 764.96 44.72 764.84 45 9 Alternative 10 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 759.04 0.00 760.75 754.11 5.54 759.81 766.6 2.74 770 767.16 17.86 771 N/A 0 N/A 776.95 33.12 782 748.61 137.26 747.55 232.89 752.55 134.33 749.57 49.28 751.68 24.26 753.09 155.08 779.69 0.09 762.42 0 762.42 7 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 758.73 0.00 760.75 754.23 6.18 759.81 767.14 3.43 770 767.73 22.85 771 N/A 0 N/A 777.94 56.24 782 748.38 130.49 747.55 191.46 752.55 113.4 749.57 36.67 751.48 22.89 752.92 127.05 779.53 0 762 0 762.00 3 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 760.26 0.13 760.75 755.65 16.24 759.81 768.57 5.3 770 768.59 30.53 771 N/A 0 N/A 778.15 61.29 782 750.2 160.84 748.35 404.61 755.37 222.13 751.04 94.35 752.22 42.56 753.63 246.6 780.64 5.33 763.17 0 763.17 18 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year 12 Hour w/ Alternative 758.74 0.00 760.75 756.22 20.78 759.81 769.23 6.14 770 769.71 40.83 771 N/A 0 N/A 780.61 120.38 782 749.32 159.16 747.76 282.68 755.37 195.99 751.04 71.06 752.1 30.8 753.48 200.84 780.72 7.44 762.4 0 762.40 7 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternative 758.73 0.00 760.75 755.70 16.65 759.81 768.63 5.37 770 768.77 32.11 771 N/A 0 N/A 779.84 101.62 782 748.73 152.67 747.66 240.9 754.33 161.41 750.49 52.83 752.03 28.08 753.35 173.14 780.37 2.04 762.12 0 762.11 4 10 Alternative 11 10-year, 2 hour w/o Alternative 761.72 5.30 760.75 759.70 5.64 759.81 766.71 2.88 770 767.8 0.72 770.31 N/A N/A N/A 778.03 1.78 780 748.68 152 747.55 241 752.55 87 749.57 49 752.3 55 753.11 156 780.8 10 765.04 48.05 764.91 48 10-year, 2 hour w/Alternative 759.04 0.00 760.75 755.12 12.17 759.81 766.53 2.64 770 767.23 18.53 771 N/A 0 N/A 776.95 33.24 782 748.61 137.98 747.55 232.82 752.55 95.47 749.57 49.3 751.71 24.34 753.09 154.39 779.7 0.11 764.92 47.02 764.88 49 10-year 12 Hour w/o Alternative 762.16 9.59 760.75 759.85 6.83 759.81 767.29 3.63 770 768.21 1.01 770.31 N/A N/A N/A 778.82 3.02 780 748.48 153 747.55 207 752.55 91 749.57 37 752.55 68 753.07 146 780.94 20 765.08 46.54 764.94 47 10-year, 12 hour w/Alternative 758.99 0.00 760.75 755.96 18.68 759.81 767.02 3.27 770 767.84 23.84 771 N/A 0 N/A 777.94 56.16 782 748.38 131.6 747.55 191.93 752.55 73.16 749.57 36.67 751.69 25.51 752.92 127.26 779.53 0 764.79 43.03 764.76 45 100-year, 2 hour w/o Alternative 762.41 12.55 760.75 759.92 7.40 759.81 768.41 5.08 770 769.52 2.08 770.31 N/A N/A N/A 779.5 4.95 780 750.4 173 748.39 414 755.37 140 751.04 94 752.68 100 753.63 242 781.1 41 765.6 56.27 765.41 56 100-year, 2 hour w/Alternative 760.26 0.13 760.75 757.35 29.86 759.81 768.5 5.21 770 768.62 30.83 771 N/A 0 N/A 777.76 52.08 782 750.2 161.15 748.35 404.65 755.37 141.98 751.04 94.35 752.22 42.58 753.63 246.2 780.64 5.36 765.56 61.21 765.49 65 100-year 12 Hour w/o Alternative 763.10 22.10 760.75 760.89 17.71 759.81 771.69 6.92 770 771.57 3.61 770.31 N/A N/A 777 780 8.08 780 751.52 191 748.71 486 755.37 174 751.04 103 753.93 217 754.39 350 781.22 76 765.91 75.93 765.55 76 100-year, 12 hour w/Alternative 759.82 0.03 760.75 759.22 46.37 759.81 769.07 5.94 770 769.47 38.55 771 N/A 0 N/A 780.6 120.22 782 749.33 165.23 747.76 283.01 755.37 128.77 751.04 71.06 752.13 34.67 753.48 200.81 780.72 7.44 765.43 52.47 765.38 56 June 11, 2004 w/o Alternative 762.72 16.57 760.75 760.32 11.06 759.81 768.84 4.64 770 769.77 2.28 770.31 N/A N/A N/A 779.99 8.03 780 748.82 167 747.66 251 754.33 123 750.49 53 753.42 140 753.38 157 781.13 49 765.3 50.57 765.15 51 June 11, 2004 w/Alternative 759.14 0.002 760.75 757.99 35.23 759.81 768.49 5.19 770 768.77 32.15 771 N/0 N/779.83 101.45 782 748.74 156.98 747.66 242.45 754.33 113.54 750.49 52.85 752.1 31.26 753.35 173.26 780.37 2.04 765.17 48.4 765.02 48 11 Landmark Plaza Tippler Jr. High Existing Walmart Pond Armory Pond 9th/Washburn Pond New Westhaven Golf Course Pond Campbell Creek Pipe Outfall Campbell Creek Cunette Outfall STR 10 06-1282 AEW-11HWY 41 Outfall Westfield Outfall Storm Sewer Confluenc Storm Sewer Confluence City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Engineering Analysis Prepared by Strand Associates, Inc.® Page 1 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 4.13-3.doc\052606 TABLE 4.13-3 SUMMARY OF EFFECTS–RANKINGS 2' or > = 1 2' or > = 1 1.5 to 1.99 = 2 1.5 to 1.99 = 2 most = 1 <1.5' = 3 <1.5' = 3 least = 1 least = 1 (ac-ft) least = 1 least = 1 least = 1 Average (all future conditions except June 11, 2004 least = 1 least = 1 most = 1 most = 1 most = 1 (ac-ft) Total Watershed- USH 41 Westfield Campbell (lowest score is best) of which is 20% higher RCNs with Existing RCNs)Total (out of 6) (out of 16) @LMP @LMP 100-year 100-year (ac-ft) LMP LMP LMP Tippler (lowest score is best) controlling controlling Watershed-Ponding # of Wide outfall to outfall to Creek LMP Ponding # of LMP LMP 10-year 100-year freeboard freebaord Tippler Ditch Pipe LMP Adequate Adequate Average Overall 100-year 100-year Wide Allowed Streets Used Sawyer Creek Sawyer Creek Outfall WATERSHED- and Watershed- Overall Allowed Streets Ditch Pipe controlling controlling @ @ Used Overflows Overflows Freeboard Freeboard Freeboard LMP LMP 2' Freeboard 2' Freeboard Used (ac-ft) Flooding Storage Flow Flow Flow WIDE Wide Average Location (ac-ft)Flooding Overflows Overflows storm storm LMP Tippler Storage RANK RANK RANK RANK RANK RANK RANK @LMP @ Tippler Storage RANK RANK RANK RANK RANK RANK RANK Rankings Ranking Alternative 1 (All Detention) 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 26.4 36 0 7 2 -1.95 -5.83 6.33 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year 12 Hour w/ Alternative 32.4 29 0 9 12 -2.12 -3.21 16.94 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 182.9 65 0 14 2 -0.57 -2.04 23.33 1.00 5.00 4.00 3.00 1.00 2.80 90.58 8 8 7 1 1 8 5.50 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year 12 Hour w/ Alternative 202 65 4 16 12 0.04 -1.89 24.46 4.00 6.00 8.00 3.00 2.00 4.60 120.05 8 7 7 1 1 7 5.17 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 20004 w/ Alternative 115.9 61 4 16 -0.36 -1.93 24.15 avg. 3.700 9 NO NO avg. 5.33 8.5 8 Alternative 2 (Increased Conveyance) 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 53 41 0 3 2 -3.32 -4.12 0.00 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 124 45 0 1 12 -3.44 -4.08 0.00 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 255.8 62 1 8 2 -1.70 -2.10 2.56 2.00 2.00 3.00 2.00 1.00 2.00 14.67 10 5 11 2 1 10 6.50 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year, 12 hour w/Alternative 425.2 65 2 9 12 -1.51 -1.80 4.34 2.00 5.00 6.00 2.00 2.00 3.40 22.32 11 7 11 7 7 9 8.67 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternative 204.7 48 1 3 -3.10 -4.05 0.00 avg. 2.700 8 NO NO avg. 7.58 9.5 9 Alternative 3 - Modified Diversion 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 8.5 30 0 4 2 -3.24 -6.90 7.26 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 3.4 12 0 0 12 -3.55 -6.32 11.24 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 120.7 56 0 9 2 -2.02 -5.32 19.00 1.00 3.00 2.00 1.00 1.00 1.60 129.81 2 4 2 6 2 4 3.33 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year, 12 hour w/Alternative 94.7 38 0 4 12 -3.36 -3.84 30.87 1.00 3.00 2.00 1.00 1.00 1.60 214.16 3 3 2 8 2 3 3.50 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternative 41.6 32 0 2 -3.44 -4.66 24.22 avg. 1.600 5 YES YES avg. 3.42 4 4 Alternative 4 (Pump Station) 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 50.7 61 3 13 2 -0.52 -1.60 5.77 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 80.6 56 4 16 12 0.07 -1.26 8.51 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 257.5 76 5 16 2 0.15 -1.24 8.70 3.00 6.00 6.00 3.00 3.00 4.20 20.83 11 9 10 2 1 9 7.00 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year, 12 hour w/Alternative 353.9 71 4 16 12 0.30 -0.83 12.76 4.00 6.00 9.00 3.00 3.00 5.00 29.26 10 9 10 6 1 8 7.33 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternative 225.2 69 4 16 0.25 -0.95 11.46 avg. 4.600 11 NO NO avg. 7.17 10.5 11 Alternative 5 (Single Mix of Alt.) 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 34.4 43 0 9 2 -1.93 -5.03 9.46 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 40.3 35 0 10 12 -1.68 -2.76 18.95 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 202.9 64 0 14 2 -0.56 -2.02 23.45 1.00 6.00 5.00 3.00 1.00 3.20 69.52 9 7 9 2 1 8 6.00 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year 12 Hour w/Alternatives 230.1 69 3 16 12 0.02 -1.88 24.49 3.00 6.00 7.00 3.00 2.00 4.20 87.46 9 8 9 5 1 7 6.50 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternatives 136.1 65 3 16 -0.16 -1.94 24.09 avg. 3.700 10 NO NO avg. 6.25 9.5 10 Alternative 6 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 26.2 33 0 4 2 -3.23 -7.20 5.53 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 32.2 19 0 0 12 -3.55 -7.08 6.19 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 179.2 53 0 8 2 -2.02 -5.66 16.25 1.00 2.00 2.00 1.00 1.00 1.40 83.25 6 2 8 7 3 3 4.83 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year, 12 hour w/Alternative 195.4 36 0 1 12 -3.54 -5.09 20.79 1.00 2.00 1.00 1.00 1.00 1.20 116.38 6 2 8 10 4 2 5.33 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternative 113.7 33 0 0 -3.55 -5.61 16.67 avg. 1.300 3 YES YES avg. 5.08 5 6 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Engineering Analysis Prepared by Strand Associates, Inc.® Page 2 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Table 4.13-3.doc\052606 TABLE 4.13-3 (CONTINUED) SUMMARY OF EFFECTS–RANKINGS 2' or > = 1 2' or > = 1 1.5 to 1.99 = 2 1.5 to 1.99 = 2 most = 1 <1.5' = 3 <1.5' = 3 least = 1 least = 1 (ac-ft) least = 1 least = 1 least = 1 Average (all future conditions except June 11, 2004 least = 1 least = 1 most = 1 most = 1 most = 1 (ac-ft) Total Watershed- USH 41 Westfield Campbell (lowest score is best) of which is 20% higher RCNs with Existing RCNs)Total (out of 6) (out of 16) @LMP @LMP 100-year 100-year (ac-ft) LMP LMP LMP Tippler (lowest score is best) controlling controlling Watershed-Ponding # of Wide outfall to outfall to Creek LMP Ponding # of LMP LMP 10-year 100-year freeboard freebaord Tippler Ditch Pipe LMP Adequate Adequate Average Overall 100-year 100-year Wide Allowed Streets Used Sawyer Creek Sawyer Creek Outfall WATERSHED- and Watershed- Overall Allowed Streets Ditch Pipe controlling controlling @ @ Used Overflows Overflows Freeboard Freeboard Freeboard LMP LMP 2' Freeboard 2' Freeboard Used (ac-ft) Flooding Storage Flow Flow Flow WIDE Wide Average Location (ac-ft)Flooding Overflows Overflows storm storm LMP Tippler Storage RAN RAN RANK RAN RANK RANK RAN @LMP @ Tipple Storage RANK RAN RAN RAN RAN RAN RANK Rankings Ranking Alternative 7 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 26.4 32 0 4 2 -3.23 -6.61 9.09 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 32.2 20 0 0 12 -3.55 -5.30 19.09 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 179.9 52 0 6 2 -2.33 -4.38 26.41 1.00 1.00 1.00 1.00 1.00 1.00 93.45 7 1 6 3 3 7 4.50 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year, 12 hour w/Alternative 197.6 45 0 4 12 -2.94 -2.26 44.66 1.00 3.00 3.00 1.00 1.00 1.80 140.33 7 4 6 3 6 5 5.17 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternative 114.2 33 0 0 -3.55 -3.16 36.60 avg. 1.400 4 ES ES avg. 4.83 5 5 Alternative 8 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 8.4 4 0 4 2 -3.24 -7.20 5.54 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 3.3 12 0 0 12 -3.55 -7.08 6.18 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 119.9 53 0 8 2 -2.02 -5.66 16.25 1.00 2.00 2.00 1.00 1.00 1.40 126.59 1 2 3 8 2 1 2.83 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year, 12 hour w/Alternative 94.4 34 0 0 12 -3.54 -5.09 20.78 1.00 1.00 1.00 1.00 1.00 1.00 204.21 2 1 4 9 2 1 3.17 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternative 41.3 30 0 0 -3.55 -5.61 16.65 avg. 1.200 1 ES ES avg. 3.00 1.0 1 Alternative 9 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 9 32 0 5 2 -3.24 -6.36 10.89 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 3.4 15 0 3 12 -3.36 -5.66 16.25 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 121.3 62 5 10 2 -2.02 -4.27 27.32 3.00 4.00 2.00 1.00 1.00 2.20 138.04 3 5 1 4 3 5 3.50 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year 12 Hour w/ Alternative 94.2 46 4 6 12 -2.82 -2.47 42.72 4.00 4.00 4.00 1.00 1.00 2.80 223.58 1 5 1 2 3 4 2.67 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternative 42.5 39 4 5 -3.18 -3.57 33.15 avg. 2.500 6 ES ES avg. 3.08 4.0 3 Alternative 10 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 9.9 33 0 4 2 -3.24 -7.20 5.54 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 4.3 12 0 0 12 -3.55 -7.08 6.18 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 129.8 54 0 8 2 -2.02 -5.66 16.24 1.00 2.00 2.00 1.00 1.00 1.40 113.36 4 3 5 9 2 2 4.17 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year 12 Hour w/ Alternative 100.2 38 0 0 12 -3.54 -5.09 20.78 1.00 1.00 1.00 1.00 1.00 1.00 188.13 4 3 5 11 5 1 4.83 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternative 46 32 0 0 -3.55 -5.61 16.65 avg. 1.200 2 ES ES avg. 4.50 3.0 2 Alternative 11 10-year, 2 hour w/o Alternative 54.6 63 3 13 10-year, 2 hour w/Alternative 10.5 38 1 6 2 -3.24 -6.19 12.17 10-year 12 Hour w/o Alternative 86.8 54 3 15 10-year, 12 hour w/Alternative 4.4 18 1 4 12 -3.29 -5.35 18.68 100-year, 2 hour w/o Alternative 264.7 76 5 16 100-year, 2 hour w/Alternative 130.4 63 5 10 2 -2.02 -3.96 29.86 3.00 4.00 2.00 1.00 1.00 2.20 117.98 5 6 4 5 2 6 4.67 100-year 12 Hour w/o Alternative 562.1 77 5 16 100-year, 12 hour w/Alternative 100.6 58 4 9 12 -2.46 -2.09 46.37 4.00 5.00 5.00 1.00 1.00 3.20 211.08 5 6 3 4 5 6 4.83 June 11, 2004 w/o Alternative 280.2 70 5 15 June 11, 2004 w/Alternative 46.6 41 4 5 -3.14 -3.32 35.23 avg. 2.700 7 ES ES avg. 4.75 6 7 ****** City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-33 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 4.14 STORM SEWER CAPACITY ANALYSIS UNDER FUTURE LAND USE CONDITIONS FOR MODELED STORM SEWERS WITH ALTERNATIVE 7 IN PLACE Figure 4.14-1 attached at the back of this report shows the capacities per storm conveyance reach under future land use conditions with Alternative 7 in place for the 2 hour duration storm event. This figure shows that there is substantial improvement in storm conveyance reach as compared to the existing condition shown in Figure 3.02-1. While some of the storm sewers show greater than 10-year capacity it is likely that inlet capacity is not sufficient to fill the pipes and allow full utilization of the storm capacity shown on Figure 4.14-1. We recommend that the City assess inlet capacity in conjunction with future street improvement projects to evaluate the benefits of adding inlets to fully realize the capacities shown in Figure 4.14-1. 4.15 STORM SEWER SIZING FOR MAIN BRANCH TO CONVEY 10-YEAR FLOW WITH ALTERNATIVE 7 IN PLACE Figure 4.15-1 shows the storm sewer upsizing necessary to convey the 10-year, 2-hour duration design storm from the Tippler Detention Basin to the Main Stem and through the Main Stem system to the Campbell Creek outfall with Alternative 7 in place under future land use conditions. Storm sewer reaches labeled as “Same” have at least a 10-year, 2-hour duration design storm capacity with Alternative 7 in place. The existing open channel from the Campbell Creek outfall to the Fox River backwater ranges in size from approximately 4-foot by 12-foot to 5-foot by 14 foot. The existing storm sewer upstream of the Campbell Creek storm sewer outfall is currently corrugated metal pipe. The City should consider upsizing these storm conveyance facilities as funds become available, as reconstruction becomes necessary and as feasible after implementation of Alternative 7. 4.16 CHANGES IN DIVERSION AT DIVERSION POINTS 1, 2, AND 3 WITH ALTERNATIVE 7 IN PLACE Figure 4.16-1 shows the changes in diversion with Alternative 7 in place under future land use conditions. This can be compared with the existing land use conditions diversion analysis shown in Figure 3.02-3. 4.17 OFF-LINE STORMWATER PONDS (NR 116) The City of Oshkosh is contemplating an off-line stormwater pond at the Armory property in the South Branch of Campbell Creek. In addition, the City will be contemplating off-line stormwater ponds in the Sawyer Creek Regional Detention Basin Study. It is our understanding that on-line stormwater ponds are not permittable by the DNR on navigable streams. The following discussion is intended to address the issues related to planning and construction of off-line stormwater detention ponds. The DNR maintains an excellent Web site to help navigate through this process at: http://www.dnr.state.wi.us/org/water/fhp/waterway/ponds.shtml . As a summary of this Web site and DNR regulations, the following is presented. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-34 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 1. A general permit or individual permit is required to construct, dredge, or enlarge any part of a pond or artificial waterbody that is either: a. Connected to a waterway. b. Located within 500 feet of a navigable waterway STEP 1: Determine if your waterway has a special designation (Area of Special Natural Resource Interest–ASNRI, Public Rights Features–PRF, Priority Navigable Water–PNW) that might affect the exemption or permit requirements. A search of the Designated Waters Database (http://www.dnr.state.wi.us/org/water/fhp/waterway/waterslist.shtml) indicates that neither Campbell Creek nor Sawyer Creek have any special designations. Lake Butte Des Morts–Fox River is designated a PNW, ASNRI, and a Natural Heritage Inventory (NHI) water. However, ponds contemplated are currently not in or adjacent to this waterbody. STEP 2: Determine if your project qualifies for a general permit. A copy of the general permit application and Fee Sheet can be found at: http://dnr.wi.gov/org/water/fhp/waterway/ponds.shtml#step2. Most off-line ponds will require an individual permit because of the following. ƒ The crest of the berm of the pond or artificial water body is closer than 35 feet from the ordinary high water mark. ƒ The pond is subject to inflow from the navigable waterway up to the 10-year, 24-hour event. STEP 3: Apply for a General Permit. The fee for a general permit for a pond is $300. STEP 4: Apply for an Individual Permit. The fee for an individual permit for a pond is $500. Relevant Definitions “Navigable waterway” means any body of water with a defined bed and bank, which is navigable under the laws of the state. In Wisconsin, a navigable body of water is capable of floating the lightest boat or skiff used for recreation or any other purpose on a regularly recurring basis. “Ordinary high water mark” means the point on the bank or shore up to which the presence and action of water is so continuous as to leave a distinct mark either by erosion, destruction of terrestrial vegetation, or other easily recognizable characteristic. In summary, off-line stormwater ponds are permittable by the DNR but they should be built with the following recommendations. DOWNSTREAM PIPE UPSIZING TO CONVEY THE 10-YEAR FLOW WITH ALTERNATE 7 IN-PLACE NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.15-11-382.021 ALT-7 Components Same Same Same Same Same Same Same Same 4' x 19' Channel@ 0.15% 5' x 16' Channel@ 0.15%5' x 16' Channel@ 0.15% WITZEL AVE N KOELLER ST SOUTHLAND AVE KNAPP ST BISMARCK AVE JOSSLYN ST N SAWYER ST US HWY 41 SOUTHBOUND US HWY 41 NORTHBOUND N WESTFIELD ST S LARK ST N WASHBURN ST S EAGLE ST N EAGLE ST FOSTER ST DOVE ST HAWK ST PORTER AVE GUENTHER ST N MEADOW ST N LARK ST W 4TH AVE LOMBARD AVE W 2ND AVE S WASHBURN ST FAUST AVE SULLIVAN ST SKYVIEW AVE NATIONAL AVE CLAYTON CT N EAGLE ST N LARK ST W 4TH AVE SULLIVAN ST 760 758 756 0 754 752 762 766 764 750 748746 768 770 774778 780 782 772 758 764 768 756 0 0 758 0 752 758 764 752 760 750 770 750 0 756 764 748 0 758 766 756 760 762 756 0 758 760 750 0 760762 752 752756 754 752 760 752 756 754 756 0 756 750 758 754 754 754 0 762 756 752 0 0 762 764 754 764 750 762 758 754 762 758 764 756 754 0 758 762 762 754 0 758 762 762 764 754 758 756 752 764 756 760 760 770 752 758 764 762 0 756 758 756 756 754 762 754 762 0 0 756 760 760 0 762 754 768 750 750 754 764 764 0 758 762 766 762 762 764 760 758 752 0 766 756 0 760 756 764 752 756 764 758 760 770 758 0 764 756 0 760 762 764 760 760 766 758 758 754 748 764 762 0 762 756 752 756 764 758 764 756 760 762 758 758 0 762 0 0 756 0 754 754 766 756 756 752 0 30 36 60 42 12 6 18 8 27 15 21 24 6540 3658 5031 3622 0 3150 3654 10 12 12 18 12 12 30 21 12 12 18 15 18 12 18 18 30 15 18 15 18 12 8 12 15 18 21 12 30 15 27 12 15 15 8 18 8 21 24 12 15 15 12 15 15 27 30 15 15 18 12 24 42 12 12 15 15 12 6 18 15 1512 15 24 24 21 12 24 24 18 12 15 12 S:\@SAI\351--400\382\021\GIS\Report Figures\Figure 4.15-1.mxd 0 400 800200 Feet Legend Storm Manhole Storm Sewer Sanitary Manhole Sanitary Sewer Water Valve Water Main Parcel Contour (2 FT.) Same Same 3' x 5'RCP Box 3' x 5'RCP Box 2 - 3' x 5'RCP Box 2 - 3' x 6'RCP Box 2 - 3' x 6'RCP Box 2 - 3' x 6'RCP Box 2 - 4' x 6'RCP Box W 4TH AVE WITZEL AVE S SAWYER ST GUENTHER ST FOSTER ST DURFEE AVE 752 754 756 750 758 748 752 752 752 754 752 756 752 750 752 752 756 752 752 752 756 750 3658 6540 18 42 12 20 15 72445031 15 12 12 0 200 400100 Feet DIVERSION ANALYSIS - WITH ALTERNATIVE 7 IN PLACE NORTH BRANCH CAMPBELL CREEK STORMWATER STUDY CITY OF OSHKOSH WINNEBAGO COUNTY, WISCONSIN FIGURE 4.16-11-382.021 Diversion PT 3 30" RCP IE = 760.27 Diversion PT 2 3' x 4.5' RCP Box With 34" Orfice in Steel Plate IE = 762.54 Diversion PT 1 High PT = 776.35 38"x60" HERCP IE = 775.25 S:\@SAI\351--400\382\021\GIS\Report Figures\Alternative 7 Diversion Analysis.mxd 0 500 1,000 250 Feet Legend Drainage Basin Boundary Sub Drainage Basin Boundary Landmark Plaza Storm Manhole Storm Sewer Water Valve Water Main Sanitary Manhole Sanitary Sewer Diversion Point Flow (CFS) Q1 = 24 Q2 = 34 Q5 = 44 Q10 = 52 Q25 = 74 Q50 = 95 Q100 = 109 Q6/11/04 = 75 Flow (CFS) Q1 = 23 Q2 = 32 Q5 = 40 Q10 = 46 Q25 = 58 Q50 = 69 Q100 = 78 Q6/11/04 = 67 Flow (CFS) Q1 = 53 Q2 = 82 Q5 = 99 Q10 = 110 Q25 = 115 Q50 = 118 Q100 = 120 Q6/11/04 = 114 Flow (CFS) Q1 = 75 Q2 = 79 Q5 = 80 Q10 = 82 Q25 = 84 Q50 = 85 Q100 = 86 Q6/11/04 = 86 Flow (CFS) Q1 = 0 Q2 = 0 Q5 = 0 Q10 = 0 Q25 = 0 Q50 = 4 Q100 = 15 Q6/11/04 = 0 Flow (CFS) Q1 = 19 Q2 = 23 Q5 = 27 Q10 = 31 Q25 = 36 Q50 = 42 Q100 = 50 Q6/11/04 = 40 City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 4–Alternative Analysis Prepared by Strand Associates, Inc.® 4-35 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S4.doc\052506 1. The pond berms adjacent to the waterway should be located outside of the floodway in areas with regulatory floodway delineations. 2. The pond berms adjacent to the waterway should be located a minimum of 10 feet away from the top of bank of the waterway in areas without regulatory floodway delineations. In this case, the 2-year flow should be able to be conveyed in the waterway without the 2-year water surface elevation in the waterway intersecting the start of berm location. 3. Fish passage must be maintained in the main channel or creek. 4. The City should further explore the regulatory requirements with the DNR regarding permitting of off-line ponds. SECTION 5 CONCLUSION AND RECOMMENDATIONS City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 5–Conclusions and Recommendations Prepared by Strand Associates, Inc.® 5-1 JHL:lr\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S5.doc\052506 5.01 GENERAL In this section, specific recommendations are presented for achieving the goals of the stormwater management plan. These recommendations are based on the discussion in Section 4 and on hydrologic analyses performed as part of this project. 5.02 RECOMMENDATIONS FOR ACHIEVING STORMWATER MANAGEMENT GOALS Section 5.03 includes Table 5.03-1 that lists the recommended stormwater plan for achieving the stormwater management goals. In addition, Section 4 lists the modeling impacts and benefits of the recommended improvements. In Section 5.05, a uniform policy for addressing and documenting future stormwater issues is proposed. While working toward the implementation of this plan, we have the following recommendations: 1. The City should complete soils investigation to determine soil characteristics in locations where detention ponds are proposed. 2. The City should adopt the Policies and Practices identified in Section 5.05 and the Drainage Evaluation Form in Appendix B. 3. The City should coordinate detention basins recommended in this study with detention basins recommended in the water quality study being performed by another consultant. 4. The City should investigate funding opportunities for the detention basins through the DNR Municipal Flood Control Grant Program. The DNR Lake Protection Grant program, River Protection Grant program, and Stewardship Grant program should also be explored. 5. The City should update City stormwater facility maps using the field survey forms and survey information provided by Strand Associates. 6. The City should further explore the regulatory requirements with the DNR regarding permitting of off-line ponds. 7. The City should investigate possible utility conflicts and space availability for each component of the recommended Alternative. 8. The City should survey the existing earthen hill at the expanded Armory detention basin site and add the cost for removal to the cost of Alternative 7. 9. The owner of Landmark Plaza should perform a study to determine how to reduce potential ponding at nodes 06-846, 06,847, and 06-1293.2 to an acceptable level considering that downstream backwater effects are alleviated as discussed in Section 3.02 C. 7. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 5–Conclusions and Recommendations Prepared by Strand Associates, Inc.® 5-2 JHL:lr\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S5.doc\052506 10. At the City’s discretion, after implementation of the components of Alternative 7, the City may want to consider providing approximately 120 acre-feet of detention at the Westhaven Golf Course or upstream of W. 20th Avenue. As discussed below, providing this detention upstream of W. 20th Avenue may be more cost beneficial to accomplish. 11. We recommend that the City assess inlet capacity in conjunction with future street improvement projects to evaluate the benefits of adding inlets to fully realize the capacities shown in Figure 4.14-1. 12. The City should consider upsizing the storm conveyance facilities shown in Figure 4.15- 1 as funds become available, as reconstruction becomes necessary and as feasible after implementation of Alternative 7. 5.03 IMPLEMENTATION PLAN Component Description Opinion of Probable Cost Implementation Schedule and Funding Source 1 Alternative 7 7a Expanded Detention at Tippler Junior High Property $1,783,100 UNPS or MFC grant 7d Storm Sewer Upsizing from Landmark Plaza to Tippler Junior High Detention $408,800 MFC grant 7b Expanded Armory Detention and Upsizing of Storm Sewer Across USH 41 $3,459,700 Project already in Capital Improvement Plan – MFC or UNPS grant 7c Detention at Vacant Lot Southeast of 9th/Washburn Intersection $1,812,300 UNPS or MFC grant TOTAL $7,463,900 Note: Costs do not include utility conflict resolution. Table 5.03-1 Stormwater Plan Components and Implementation Plan (Costs include 25 Percent Engineering and Contingencies) Table 5.03-1 provides a listing of the recommended stormwater management plan components, the cost of each component, and the implementation schedule and possible funding source, if applicable. As discussed in Section 4.13, Alternative 7 best meets the evaluation criteria for a recommended alternative. However, we feel that after implementation of the components of Alternative 7, the City should consider providing 120 acre-feet or more of detention at the Westhaven Golf Course or upstream of W. 20th Avenue to deal with persistent flooding problems along W. Washburn Street between W. 20th Avenue and W. 9th Avenue. and southeast of Allerton Drive, if deemed necessary in the future. The large cost to get stormwater to and build detention at the Westhaven Golf Course is a deterrent to providing this 120 acre-feet of detention. Detention upstream City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 5–Conclusions and Recommendations Prepared by Strand Associates, Inc.® 5-3 JHL:lr\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S5.doc\052506 of W. 20th Avenue may be more readily accessible, thus decreasing the cost of providing this detention. 5.04 FUNDING OPPORTUNITIES Appendix C includes a brochure produced by Strand Associates that describes some of the more popular DNR grant programs. The City of Oshkosh may want to investigate the programs for possible funding of the recommended stormwater plan components. The following programs are available: ƒ Municipal Flood Control Grant ƒ Urban Nonpoint Source and Stormwater Grant ƒ Targeted Runoff Management Grant ƒ Lake Planning and Management Grant ƒ River Protection Planning and Management Grant ƒ Stewardship Grant The Municipal Flood Control grant would be ideal for dry detention basins and wet detention basins in this watershed because of the documented flooding problems and property damage in the watershed. The Urban Nonpoint Source and Stormwater grant would be ideal for wet detention basins that are able to accept the 2-year flow and thus treat the smaller storms for total suspended solids. The DNR Lake Protection Grant program, River Protection Grant program, and the Stewardship Grant program should also be explored to see if these projects would be a fit for these grant programs. The Stewardship Grant program may assist in land acquisition to protect water resources and green space for facilities that might be able to incorporate some level of outdoor recreation facilities. 5.05 POLICIES AND PRACTICES A. General As in any typical community, localized drainage issues commonly arise that may affect a limited number of areas. These issues may be caused by a deficiency in a drainage facility, a maintenance issue, or alterations of property during maintenance or construction projects. In reviewing Section 2.03-Locations of Existing Flooding, it is evident there are a number of these issues. It is recommended that the City of Oshkosh develop a uniform policy for addressing localized drainage issues and maintain a record of where these issues have occurred. This policy should establish the procedure to be followed in resolving future drainage issues in the City. This will ensure that future issues are addressed in an equitable and timely manner and locations of recurring problem areas can be identified for future planning purposes. Section 5.05-B includes a recommended policy for addressing drainage issues. This policy should be reviewed by the City of Oshkosh. City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 5–Conclusions and Recommendations Prepared by Strand Associates, Inc.® 5-4 JHL:lr\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S5.doc\052506 B. Recommended Policy 1. Problem Identification and Drainage Evaluation a. After receiving a verbal or written complaint from a resident, the resident should be provided a Drainage Evaluation Form (Appendix B). The resident should complete Parts A, B, and C of the form and return it to the City of Oshkosh. b. Within 30 calendar days of receiving the form with completed Parts A, B, and C, a City of Oshkosh representative will inspect the location and review the information submitted by the resident. The City of Oshkosh representative will complete Part D of the form based upon this review. c. The City of Oshkosh representative will make a recommendation in Part E of the form regarding action to be taken (if any) to alleviate or mitigate the problem. Decision-making criteria will be clearly stated and in accordance with Section B.2., below. d. A copy of the completed Drainage Evaluation Form will be returned to the resident. Additional copies will be maintained in the City of Oshkosh files and the form and complaint location will be incorporated into the City’s GIS system for future analysis of drainage problem area trends. 2. City of Oshkosh Authority The City of Oshkosh’s authority in addressing individual drainage issues should be determined on a case-by-case basis. Prior to the City of Oshkosh taking corrective action, the ownership of the properties causing the problem and being damaged should be verified. Where the City of Oshkosh has easement rights or where the issue involves the obstruction of a natural watercourse (under Section 88.90 of the Wisconsin Administrative Code), the City of Oshkosh can move to correct the problem. If the drainage issue results from an activity that is not located on a City of Oshkosh property or right-of-way, does not violate a City Ordinance, or does not involve obstruction of a natural watercourse, the City of Oshkosh may be without jurisdiction to act. 3. Determination of City of Oshkosh Responsibility In cases where it is determined that the City can take corrective action to address the drainage deficiency, the following steps should be taken: a. Alternative solutions to the identified problem should be developed and incorporated into the City of Oshkosh Stormwater Management Plan(s). City of Oshkosh, Wisconsin North Branch Campbell Creek Stormwater Management Plan Section 5–Conclusions and Recommendations Prepared by Strand Associates, Inc.® 5-5 JHL:lr\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\S5.doc\052506 b. Opinions of probable engineering and construction costs of individual projects should be prepared. c. As part of the annual budget process, projects to be constructed each year should be selected based upon priority ranking and funding availability. 5.06 CONCLUSION The goal of this report has been to provide the City of Oshkosh with a framework of how stormwater management facilities should be developed to address existing flooding and future development issues. It is not expected that all the recommended measures will be constructed immediately. Implementation of measures recommended in this report will help to relieve the flooding in the Campbell Creek watershed and will reduce the flooding at Landmark Plaza. APPENDIX A FLOODING PHOTOGRAPHS City of Oshkosh, Wisconsin Appendix A–June 10 and 11, 2004 North Branch Campbell Creek Stormwater Management Plan Flooding Photographs Prepared by Strand Associates, Inc.® Page 1 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Appendix A.doc\052506 Looking north at Landmark Plaza parking lot. Looking north at back of eastern Landmark Plaza building. Looking west at ditch entering Landmark Plaza. Looking east at ditch along south property line at Landmark Plaza. Looking east at south side of eastern Landmark Plaza building. Looking northwest at Landmark Plaza parking lot. City of Oshkosh, Wisconsin Appendix A–June 10 and 11, 2004 North Branch Campbell Creek Stormwater Management Plan Flooding Photographs Prepared by Strand Associates, Inc.® Page 2 of 2 JHL:pll\S:\@SAI\351--400\382\021\Wrd\Report-Oshkosh Campbell Creek SMP\Appendix A.doc\052506 Looking west from Washburn Street bridge over Sawyer Creek Looking southwest at Campbell Creek outfall pipe downstream of Witzel Ave. Looking south along Washburn Street/USH 41 from south of W. 9th Avenue Looking south along Washburn Street/ USH 41 from south of W. 9th Avenue Looking north at the intersection of Mason Street and W. 4th Avenue Looking north at Franklin School from intersection of Huntington Place/ W. 9th Avenue APPENDIX B DRAINAGE EVALUATION FORM City of Oshkosh, Wisconsin Drainage Evaluation Form JHL:pll.\050506\S:\@SAI\351--400\382\021\WRD\REPORT-OSHKOSH CAMPBELL CREEK SMP\AP B-DRAINAGEEVALFORM.DOC Part A - General (To be completed by resident) Today’s Date: Location of Drainage Problem (include building name, parking lot number or feature name): Building Manager / Contact Name: Phone Number: (Office) _______________________________________(Mobile/Pager) Part B - Description of Problem (To be completed by resident) Provide detailed description or sketch or photo of the problem in the space below: JHL:pll.\050506\S:\@SAI\351--400\382\021\WRD\REPORT-OSHKOSH CAMPBELL CREEK SMP\AP B-DRAINAGEEVALFORM.DOC How frequently or under what conditions does this problem occur (heavy rain, prolonged wet weather, frozen ground, etc.)? Provide approximate dates of occurrence: Describe damages incurred on your property. Note exterior versus interior damage: Have you attempted to correct this problem? If so, what measures were taken? Part C - Attachments 1. Photographs Attached? Yes No 2. Building or Utility Plans (if available) Attached? Yes No 3. Reports/Records (if available) Attached? Yes No 4. Other (Describe) JHL:pll.\050506\S:\@SAI\351--400\382\021\WRD\REPORT-OSHKOSH CAMPBELL CREEK SMP\AP B-DRAINAGEEVALFORM.DOC Part D – City Engineer’s Inspection Name of Inspector: Date of Field Inspection: Inspector’s Notes: List of properties affected: Photos: Attached or N/A Is drainage problem: 1. Located on City property? Yes No 2. Associated with a City-owned or -maintained storm sewer facility or drainage way? Yes No 3. Caused by damage to the storm sewer or obstruction of the drainage way? Yes No Part E - Evaluation/Responsibility (To be completed by City Engineeer) Recommended Action: City of Oshkosh, Wisconsin Drainage Evaluation Form JHL:pll.\050506\S:\@SAI\351--400\382\021\WRD\REPORT-OSHKOSH CAMPBELL CREEK SMP\AP B-DRAINAGEEVALFORM.DOC Comments: ROUTING: (PLACE CHECK MARK BY APPLICABLE REVIEWERS) City Engineer (All Submittals) City Building Inspector (Where Applicable) REVIEWED BY: ______________________________________________ City Engineer ______________________________________________ City Building Inspector APPENDIX C STORMWATER FUNDING BROCHURE