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HomeMy WebLinkAboutBrown and Caldwell Gallups/Merritts Creek Watershed Storm Water Management Amnd. No 2 13594 AMENDMENT NO.2 The CITY OF OSHKOSH, hereinafter referred to as CITY, and BROWN AND CALDWELL, 8383 Greenway Boulevard, Suite 600, Middleton, WI 53562, hereinafter referred to as the CONSULTANT, entered into an agreement for GALLUPS/MERRITTS CREEK WATERSHED STORM WATER MANAGEMENT PLAN on July 1, 2015. Paragraph C in ARTICLE XI. PAYMENT included the provision that costs for additional services shall be negotiated and set forth in a written amendment to this AGREEMENT executed by both parties prior to proceeding with the work covered under the subject amendment. THEREFORE, the CITY and the CONSULTANT agree to insert the following paragraph after the first paragraph in ARTICLE III. SCOPE OF WORK: The CONSULTANT shall provide the services described in the CONSULTANT's Attachment A dated June 11,2019. The CITY and the CONSULTANT further agree to insert the following bullet point after the first bullet point in Paragraph A of ARTICLE XI. PAYMENT: • Payment for Amendment No. 2 shall be a Time and Materials Sum not to exceed $13,975 (Thirteen Thousand Nine Hundred Seventy Five Dollars). All other terms contained within the July 1,2015 agreement remain unchanged and in effect. In the Presen of: CONSULTANT Ate— By: �7 Nov, 1 A.( 1pt 1)leek_ k__AukxtRoppatd U (Seal of Consultant if a Corporation (Specify Title) By: (Specify Title) CITY OF KOSH ess er � ',' ;h-•f Crir/H,�.�.� clkP 4-5 And: Z itness) Pamela R.Ubrig, City Clerk AP OVED: I hereby certify that the necessary provisions have been made to pay the liability which which will accrue under this Agreement. rney City Comptro er I:\Engineering\Tracy Taylor\James'Agreements\Brown&Caldwell\2015\Gallups-Merritts Crk\B&C CA#2- Page 1 of 1 Callups-Merritts Crk Watershed SWMP_7-26-19.doa Attachment A Amendment#2 to Gallups/Merritts Creek Watershed Storm Water Management Plan Brown and Caldwell Project# 148104 RECEIVED City of Oshkosh Reference: Authorization Date: 6/9/2015 JUN 11, 2019 2 12019 DEFT O V8 W This Attachment A documents additional scope and tasks requested of Brown and Caldwell •b�'tl3g,�JN iN S City of Oshkosh(City)for services under the Gallups/Merritts Creek Watershed Storm Water Management Plan project(City Authorization Date 6/9/15; BC Project# 148104)agreement dated July 1, 2015. Scope Changes Add Task 10 to the scope of work as follows: Task 10. Analysis of Culvert Crossing at South End of Airport Runway(#18—36) The Wittman Regional Airport is planning changes to the existing twin 63"x 87"CMPA culverts located at the south end of Runway#18-36. The airport will be reconstructing Taxiway A and plans to replace the twin 63" x 87" CMPA culverts. The airport is considering two pipe sizes,twin 78"RCP or twin 53"x 83"HERCP culverts in the vicinity of Taxiway A. The existing twin CMPA culverts will not be fully replaced under Runway#18-36 until the runway pavement requires replacement. The City wants to analyze the impacts of increasing the existing culvert capacity regarding flooding potential west and east of the airport. Under this new task, BC will conduct the following work. l0a Revise the existing XPSWMM model to replace the existing twin CMPA to twin 78" RCP culverts under Taxiway A and Runway#18-36. 10b Revise the existing XPSWMM model to replace the existing twin CMPA to twin 53"x 83"HERCP culverts under Taxiway A and Runway#18-36. 10c Revise the existing XPSWMM model to replace the existing twin CMPA to a 6' x 12' concrete box culvert. It is anticipated that this will increase peak flow rates and flow volumes downstream of Wittman Regional Airport. Initial results of the modeling will be documented and discussed with the City. No further analysis of mitigation measures will be conducted. l Od Conceptually resize a dry detention basin to be located west of the twin CMPAs. The detention basin will be sized to prevent overland discharge north(to the Glatz Creek Watershed) under the 100 year, 3-hour rain event. The conceptual dry detention basin will be incorporated into the scenarios described under subtasks 10b and l Oc. l0e Run the XPSWMM model with the revisions described above under the following rain events: Table 1 Storm Events for Modeling Rainfall Duration Rainfall Depth Recurrence Interval (hours) (inches) 10-year 3-hour 2.28* 25-year 3-hour 2.85* 100-year 3-hour 4.06* June 2008 15-hour 4.94** * Rainfall Frequency Atlas of the Midwest(1992) Gallups_Merritts Amend 2 Final 1 Attachment A Amendment#2 to Gallups/ Merritts Creek Watershed Storm Water Management Plan Brown and Caldwell Project# 148104 City of Oshkosh Reference: Authorization Date: 6/9/2015 June 11, 2019 ** Rain duration and depth recorded at Wittman Regional Airport,Oshkosh,WI 1 Of Prepare maps and tables summarizing the runoff surface ponding depth and extent for each rain event in Table 1 under the conditions described in subtasks 10a, 10b, and 10c. lOg Prepare an additional section of the Gallups/Merritts Creek Watershed Regional Storm Water Management Plan(Task 7)describing the results of the analysis under this amendment. l Oh The following meetings are included with this budget: 1) Attend(via conference call) a meeting with City Staff, Wittmann Regional Airport representatives, and OMNNI Associates(Airport's Consultant)to discuss the proposed Taxiway A project. 2) Hold one meeting with City Staff at the City of Oshkosh City Hall to review the results from the initial analysis. 3) Hold a second meeting with City Staff at the City of Oshkosh City Hall to review the results from the final analysis. Revision to Attachment A—Schedule. The schedule for final deliverables is revised to December 31,2019. Budget Amendment • All work will be conducted under the terms and conditions as described in the Gallups/Merritts Creek Watershed Storm Water Management Plan agreement dated July 1, 2015. The Amendment budget is provided below: Additional Task Hours Costs #10 Analysis of Culvert Crossing at South End of Airport Runway(#18—36) 88 $13,975.00 Current contract amount= $128,221.00 Amendment#1: $ 6,967.00 Amendment#2: $ 13,975.00 Amended Contract Amount: $149,163.00 Assumptions 1) All work on this amendment will be completed by December 31, 2019. Gallups_Merritts Amend 2 Final 2