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City of Oshkosh
Stormwater Management
Common Council WorkshopCommon Council Workshop
Sawyer Creek WatershedSawyer Creek Watershed
September 1, 2009September 1, 2009
2
Overview
• Sawyer Creek Storm Water Management Plan
– Watershed Characteristics
– Plan Goals
– Existing Conditions
– Alternatives Analysis
• Campbell Creek Storm Water Management
Plan
– Review of Alternatives
• Water Quality Analysis
3
Overview
• Combined Mitigation Strategies for Sawyer
Creek and Campbell Creek Watersheds
– Projects Independent of Westhaven Golf Course
Decision.
– Projects Dependent on Westhaven Golf Course
Decision.
– Options Analysis
• Future Direction from Common Council
4
Sawyer Creek
5
Municipality Area (Acres)Area
(%)
City of Oshkosh 3,182 31.7
Town of Algoma 1,409 14.1
Town of Omro 954 9.5
Town of Nekimi 3,015 30.1
Town of Utica 1,466 14.6
Total 10,026 100%
Sawyer Creek Watershed
Sawyer Creek Watershed Characteristics
STH 44
STH 21
US
H
4
1
6
• Reduce or eliminate street flooding to the maximum extent
practicable.
• Reduce 100-year floodplain elevations to remove habitable
buildings from the 100-year floodplain, where possible.
• Culverts/Bridges at street crossings should convey stormwater
runoff from a 100-year storm event without roadway overtopping,
where possible. If this is not possible, provide passage of the
greatest storm event possible (25-year to 50-year being desirable).
• Stormwater management practices to be employed should improve
stormwater quality by reducing the amount of suspended solids and
attached nutrients in the runoff to the maximum extent practicable.
Sawyer Creek Plan Goals
7
Flooding Review Points:
1.W. 20th Ave. / Clairville Rd.
2.Oakwood Rd.
3.9th Ave. Bridge Locale.
4.Westhaven Bridge Locale.
5.Washburn St. near Kienast property.
6.North Westfield St. and Taft Ave.
7.Arthur Ave., Van Buren Ave.,
Coolidge Ave. Locale.
8.Dove Street Locale.
9.Westhaven Dr., Maricopa Dr.,
Dickinson Ave., Washburn St. Locale
(Portion within Campbell Creek
watershed)
6. Taft Ave. and Eagle St.
(Looking West)
5. 829 N. Washburn
(Looking South)
Rec. Bridge (Looking South
from Wellington)
1. W. 20th Ave. / Clairville
(Looking South)
Sawyer Creek Existing Conditions
US
H
4
1
STH 21
8
Sawyer Creek Existing Conditions
Flooding Analysis Points:
1150 South Oakwood Road
Mercy Medical Generator
729 North Washburn Street
1020 North Westfield Street
1036 North Lark Street
Mercy Medical Center
(Looking North from 9th)
Oakwood Road (Looking
East from Ruschfield)
Kienast Bridge
(Looking West)
US
H
4
1
STH 21
9
Sawyer Creek Existing Conditions
100Sawyer Street
50-100Westfield Drive
100USH 41 and Frontage Roads
5-10Naslund Residence
5-10Pommerening Residence
25-50Westhaven Drive
25-50West 9th Avenue
25-50Oakwood Road
<2Pedestrian Bridge 1
<2Pedestrian Bridge 2
25-50Clairville / CTH K
Approximate Overtopping
Frequency (Design Storm
Event)
Roadway Crossing
Bridge Overtopping Frequency
10
Considered Detention
•Vacant Land N.E. of Clairville/W. 20th
•Vacant Land (17.1 Ac) N. of Mercy
•Vacant Land (14.1 Ac) W. of Fleet Farm
•Vacant Area S. of Meadow Park Dr. and W.
of Badger/Oakwood intersection
•Various Locations in Rural Watersheds
Upstream of Clairville
Sawyer Creek Alternatives Analysis
US
H
4
1
STH 21
STH 44
11
Sawyer Creek Recommended
Alternatives Analysis
Alt.
James
Road/
HWY 91
Detention
Basin
Westhaven
West Golf
Course
Detention
Basin
Oakwood
Road/
Badger
Avenue
Detention
Basin
Channel
Improvement
s At,
Upstream
and
Downstream
of Westfield
Street from
Mead & Hunt
2000 Study
MODIFIED
Channel
Improvement
s At,
Upstream
and
Downstream
of Westfield
Street
HWY 41/
Frontage Road
Reconstruction
Campbell
Creek
Alternativ
e 13B in
place
Campbell
Creek
Tipler and
Armory
Detention
Basins
Campbell
Creek
Alternativ
e 12 in
place
1 X X
2 X X
3 X X
4 X X
5 X X X X X
6 X X X X X X
7 X X X X X
8 X X X X X
9 X X X X X
12
Pros Cons
Rural land less
expensive than urban
land.
Excellent location for
reducing peak flows
from upstream in the
watershed.
Provides 229 acre-
feet of storage
volume
Potential wetland
issues
Potential need for soil
undercutting for
embankment
construction
Potential need for
dewatering during
construction.
No Quality Benefit.
Alternative 1 – Detention Basin Located
near James Road and STH 91
Sawyer Creek Recommended
Alternatives Analysis
US
H
4
1
STH 21
STH 44
13
229.1814.768415644367897100-
Year
167.5812.88811413595167650-Year
111.8810.62761082553841025-Year
61.6808.4466651772516910-Year
7.4805.4684513111212-Year
Max.
Storage
(ac-ft)
Max. Water
Surface
Elevation
Percent
Reduction
Peak Discharge
from Detention
Basin (cfs)
Peak Flow
Remaining in
Creek (cfs)
Local flows to
Detention
Basin (cfs)
Peak Flow into
Detention Basin
from Creek (cfs)
Storm
Event
Alternative 1 – Detention Basin Located
near James Road and STH 91
Sawyer Creek Recommended
Alternatives Analysis
14
Westhaven East
Westhaven West
Sawyer Creek
Westhaven East
Westhaven West
Campbell Creek
Alternative 2 – Westhaven West Golf
Course Detention Basins
Sawyer Creek Recommended
Alternatives Analysis
US
H
4
1
STH 21
STH 44
15
Pros Cons
Helps alleviate flooding downstream.
Makes use of “open” land in urbanized area of the City.
Location is ideal for reducing peak discharges downstream
in the watershed.
Provides 200 acre-feet of storage volume.
Provides stormwater quality treatment for 130.5 acres.
Potential wetland issues
Potential need for soil undercutting for embankment
construction
Potential need for dewatering during construction.
Korobago and Wauseon soils may be underlain by sandy
layers that may necessitate a clay liner in the wet basin
areas.
Storm
Event
Peak Flow into
Detention
Basin from
Creek
(cfs)
Local Flows To
Detention Basin
(cfs)
Peak Flow
Remaining in
Creek
(cfs)
Peak
Discharge
from Detention
Basin (cfs)
Percent
Reduction
Max. Water
Surface
Elevation
Max.
Storage
(ac-ft)
2-Year 0 23 391 4 83 767.61 6.7
10-Year 1 50 968 14 73 768.19 14.8
25-Year 190 56 1343 84 66 770.80 60.1
50-Year 505 62 1677 141 75 774.38 128.7
100-Year 994 70 2223 193 82 777.82 199.9
Alternative 2 – Westhaven West Golf Course Detention Basins
Sawyer Creek Recommended
Alternatives Analysis
16
Alternative 2 – Westhaven West Golf Course Detention Basin
Golf Course Operations are Retained
Sawyer Creek Recommended
Alternatives Analysis
Oa
k
w
o
o
d
R
o
a
d
9th Avenue
WesthavenDrive
17
Sawyer Creek Recommended
Alternatives Analysis
Alternative 3 – Oakwood Road / Badger
Avenue Detention (Southwest Industrial Park)
US
H
4
1
STH 21
STH 44
18
Oakwood Road/Badger Avenue Detention Basin Site
Looking Southwest
Oakwood Road/Badger Avenue Detention Basin Site
Looking Southwest
Pros Cons
TSS reduction
Makes use of “open” land in urbanized area of the
City.
Provides 9.4 acre-feet of storage volume during
100-year storm resulting in reductions in peak
discharge rate and flood elevations downstream of
the detention basin.
Potential need for soil undercutting for embankment
construction
Potential need for dewatering during construction.
Wauseon soils may be underlain by sandy layers that
may necessitate a clay liner in the wet basin areas.
Small effect on peak discharge rates and 100-year flood
elevations along Sawyer Creek.
Alternative 3 – Oakwood Road / Badger
Avenue Detention (Southwest Industrial Park)
Sawyer Creek Recommended
Alternatives Analysis
19
Storm Event
Peak Inflow
(cfs)
Peak
Discharge
(cfs)
Percent
Reduction
Maximum
Water Surface
Elevation
Max
Storage
(ac-ft)
2-Year 12 2 83 817.07 3.6
10-Year 26 6 77 818.04 7.4
25-Year 36 20 44 818.23 8.2
50-Year 47 31 34 818.34 8.7
100-Year 67 53 21 818.51 9.4
Alternative 3 – Oakwood Road / Badger Avenue
Detention Basin (Southwest Industrial Park)
Sawyer Creek Recommended
Alternatives Analysis
20
Alternative 4 – Channel Improvements
– Westfield Street Locale
Sawyer Creek Recommended
Alternatives Analysis
21
Westfield Street LocaleWestfield Street Locale
Pros Cons
No land acquisition.
Improvement in water surface profile in vicinity and
just upstream of improvements.
Potential wetland issues.
Potential dredging issues.
Chapter 30 permit issues.
No reduction in peak discharge rates.
Alternative 4 – Channel Improvements
– Westfield Street Locale
Sawyer Creek Recommended
Alternatives Analysis
Oshkosh
Avenue
Red Arrow
ParkWestfield Street
22
Alt.
James
Road/
HWY 91
Detention
Basin
Westhaven
West Golf
Course
Detention
Basin
Oakwood
Road/
Badger
Avenue
Detention
Basin
Channel
Improvement
s At,
Upstream
and
Downstream
of Westfield
Street from
Mead & Hunt
2000 Study
MODIFIED
Channel
Improvement
s At,
Upstream
and
Downstream
of Westfield
Street
HWY 41/
Frontage Road
Reconstruction
Campbell
Creek
Alternativ
e 13B in
place
Campbell
Creek
Tipler and
Armory
Detention
Basins
Campbell
Creek
Alternativ
e 12 in
place
1 X X
2 X X
3 X X
4 X X
5 X X X X X
6 X X X X X X
7 X X X X X
8 X X X X X
9 X X X X X
Alternatives 5 through 9 are different combinations of the components contained in Alternatives 1
through 4.
Sawyer Creek Recommended
Alternatives Analysis
23
Alt.
Storage in Sawyer
Creek
Rank Based On Total
Storage Provided
1 229.1 6
2 199.9 7
3 21.9 8
4 0 9
5 430.8 1
6 430.8 1
7 251 3
8 251 3
9 251 3
Assessment Parameter 1 – 100-year Storage Volume Provided (ac-ft)
Sawyer Creek Recommended
Alternatives Analysis
24
Alt.
Existing 100-Year Flow Rate at
Sawyer Creek
(cfs)
100-Year Flow Rate at Sawyer
Creek with Alternative in Place
(cfs) % Reduction Rank1
1 3401 2807 17.5% 7
2 3401 2658 21.8% 3
3 3401 3375 0.8% 8
4 3401 3391 0.3% 9
5 3401 2275 33.1% 2
6 3401 2210 35.0% 1
7 3401 2746 19.3% 4
8 3401 2765 18.7% 6
9 3401 2746 19.3% 5
1 The tiebreaker between Alternatives 7 and 9 goes to Alternative 7 because the modified Westfield channel
improvements would be less costly to implement than the original Mead and Hunt Westfield channel improvements.
Assessment Parameter 2 – Percent Reduction in 100-Year Peak Flow Rate
at the Fox River / Sawyer Creek Confluence
Sawyer Creek Recommended
Alternatives Analysis
25
Alt.
Average Freeboard at 5
Locations (feet) Rank
1 -0.366 7
2 -0.228 5
3 -1.028 8
4 -1.038 9
5 0.304 2
6 0.336 1
7 -0.244 4
8 -0.254 6
9 -0.228 3
Freeboard is the distance between the flood water surface and the first floor elevation of structures.
(-) = Average 100-Year Water Surface Elevation Above the 1st Floor Elevation
(+) = Average 100-Year Water Surface Elevation Below the 1st Floor Elevation
Assessment Parameter 3 – Greatest Freeboard at the 5 Flooding Analysis
Points
Sawyer Creek Recommended
Alternatives Analysis
26
Roadway Crossing Exist. Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 Alt 8 Alt 9
Clairville Road / W. 20th Avenue 25-50 100 25-50 25-50 25-50 100 100 100 100 100
Pedestrian Bridge 2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2
Pedestrian Bridge 1 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2
Oakwood Road 25-50 25-50 25-50 25-50 25-50 50-100 50-100 25-50 25-50 25-50
9th Avenue 25-50 50-100 50-100 25-50 25-50 100 100 50-100 50-100 50-100
Westhaven Drive 25-50 50-100 50-100 25-50 25-50 100 100 50-100 50-100 50-100
Witzel Ave.(CTH E) 100 100 100 100 100 100 100 100 100 100
Pommerening Residence 5-10 5-10 5-10 5-10 5-10 10-25 5-10 5-10 5-10 5-10
Naslund REsidence 5-10 5-10 5-10 5-10 5-10 5-10 5-10 5-10 5-10 5-10
USH 41 and Frontage Roads 100 100 100 100 100 100 100 100 100 100
Westfield Drive 25-50 25-50 100 25-50 50-100 100 100 100 100 100
Sawyer Street 100 100 100 100 100 100 100 100 100 100
Rank 6 7 9 8 1 2 4 3 5
1 Tie breaker between Alternatives 5 and alt 6 goes to Alternative 5 because it is less costly to implement in the Campbell Creek
watershed.
2 Tie breaker between Alternatives 8 and 9 goes to Alternative 8 because Alternative 9 requires land acquisition at occupied land,
Alternative 8 is vacant land.
3 Tie breaker between Alternatives 3 and 4 goes to Alternative 3 because Alternative 3 provides water quality side benefit for the same
water quantity benefit.
Assessment Parameter 4 – Average Storm Passed at Bridges Assessed
Sawyer Creek Recommended
Alternatives Analysis
27
3
6
4
1
2
9
8
5
7
Rank for Greatest
Freeboard at the 5
Flooding Analysis
PointsAlt.
Rank for 100-year
Storage Volume
provided
Rank for Percent
Reduction in 100-year
Peak Flow Rate at the
Fox River/ Sawyer
Creek Confluence
Rank for Average
Storm Passed at
Bridges Assessed
Average Rank
Based on 4
Assessment
Parameters
1 6 7 6 7
2 7 3 7 6
3 8 8 9 8
4 9 9 8 9
5 1 2 1 2
6 1 1 2 1
7 3 4 4 3
8 3 6 3 5
9 3 5 5 4
Rank Based on Average of Four Assessment Parameters
Sawyer Creek Recommended
Alternatives Analysis
28
Campbell Creek
29
• Alternatives 12 and 13B had best flooding
reduction performance.
• Alternative 12:
– Tipler Dry Detention Basin – Council Approved
– Armory Wet Detention Basin – Council Approved
– 9th and Washburn Wet Detention Basin
• Alternative 13B
– Tipler Dry Detention Basin – Council Approved
– Armory Wet Detention Basin – Council Approved
– Westhaven Golf Course Detention Basins
Campbell Creek Review of Alternatives
30
Benefits
•140.3 acre-feet of Storage
•2.3 feet Freeboard at Landmark
Plaza for 100-year storm
•Increased # of Streets with 10-
Year Storm Capacity vs.
Existing Conditions
Alternative 12
Campbell Creek Review of Alternatives
Tipler, Armory and 9th &
Washburn
31
Alternative 13B
Benefits
•215.1 acre-feet of Storage
•3.6 feet Freeboard at Landmark
Plaza for 100-year storm
•Increased # of Streets with 10-
Year Storm Capacity versus
Existing Conditions and
Alternative 12
Tipler, Armory and Golf Course
Campbell Creek Review of Alternatives
32
Alternative 13B
Campbell Creek Review of Alternatives
Golf Course Operations are
Retained
WesthavenDrive
Maricopa Drive
33
Water Quality Analysis
• Wisconsin DNR Storm Water Discharge Permit
Coverage issued on January 2, 2007
• Permit requires reduction of pollution to waters
of the state
• Pollutant of Interest: Total Suspended Solids
(TSS)
• Must reduce Base Load by 40% by 2013
34
Water Quality Analysis
• City of Oshkosh TSS Pollution Information
– Base Load: 1693 tons/year
– Required Reduction: 677 tons/year (40% of 1693)
– Current Practices Reduction: 309 tons/year
– Additional Reduction Required: 368 tons/year (677-
309)
35
Combined Mitigation Strategies for Sawyer
Creek and Campbell Creek Watersheds
• Sawyer Creek
– Alternatives 6 and 7 have best performance based
upon flood reduction.
• Alternative 6 impacts Westhaven Golf Course
• Alternative 7 does not impact Westhaven Golf Course
• Campbell Creek
– Alternatives 12 and 13B have best performance
based upon flood reduction
• Alternative 13B impacts Westhaven Golf Course
• Alternative 12 does not impact Westhaven Golf Course
36
Projects Independent of Golf Course
Decision
• James Road / STH 91 Detention Basin
• Oakwood Road / Badger Avenue Detention
Basin
• Channel Improvements along Sawyer Creek in
Westfield Street Area
• Armory Detention Basin1 – Council Approved
• Tipler Detention Basin – Council Approved
1. If 9th and Washburn Location selected, Armory Detention Basin requires acquisition of approximately
5 acres of Commercially zoned land.
37
Project Cost Analysis
None
None1
None
12.8
None
TSS Pollution
Removed
(tons / year)
$ 52,800$ 17,770,800336.6Total:
$ 42,170$ 1,750,00041.5Tipler Detention Basin
$ 157,510$ 6,946,20044.1Expanded Armory
Detention Basin2
NA$ 727,6000Channel Improvements in
Westfield Street Area
$ 49,130$ 1,076,00021.9Oakwood Road / Badger
Avenue Detention Basin
$ 7,271,000
Estimated Cost
$ 31,700229.1James Road / USH 91
Detention Basin
Cost per ac-ft
Storage
Storage
Provided (ac-ft)
Component
Projects Independent of Golf Course
Decision
1. Armory Detention Basin not estimated to reduce pollution due to being adjacent to a navigable waterway. DNR
regulations typically require smaller storm events to remain within the waterway. These smaller storm events carry the
majority of pollutants. During Design Phase staff will work with DNR to explore every possibility to include water quality
benefit.
2. If 9th and Washburn Location selected, Armory Detention Basin requires acquisition of approximately 5 acres of
Commercially zoned land.
38
Project Cost Analysis
13.8
68.1
TSS Removed
(tons/year)
$ 298,750$ 8,634,00028.99thand Washburn
$ 24,531,800
Estimated Cost
$ 69,260354.2Westhaven Golf Course1
Cost per ac-ft
Storage
Storage
Provided (ac-ft)
Component
Projects Dependent on Golf Course
Decision
1. This option allows the Armory Detention Basin to be reduced to by eliminating the purchase of 5 acres
of Commercially zoned land.
39
Summary
Options Analysis
NA
12.37
2,182
683
$ 265,778,500
591
NA
NA
Existing Conditions
1,2951,535
Number of Dwelling Units
within City within 100-year
Flood Plain1
$ 37,851,800$ 26,404,800Project Cost
6.408.19Miles of Streets within 100-
year Flood Plain
410496
Number of Residential City
Parcels within 100-year Flood
Plain
$ 176,244,500$ 192,006,500Estimated City Parcel Value
in 100-year Flood Plain
359385100-year Flood Plain Area
(ac)
80.926.6Total TSS Removed
(tons/year)
Storage Provided (ac-ft)677.6365.5
Impacting WesthavenNo Impact to Westhaven
To make up the pollution reduction difference between the two options, approximately 460 acres of Commercial, Industrial
and Institutional Land would require treatment with Bio-filters. The estimated construction cost would be $4.2 million, with
estimated annual maintenance costs of $620,000 vs. $28,000 for the detention basins.
40
Future Direction from Common Council
• To utilize Westhaven Golf Course, or not.
• To begin implementation of Sawyer Creek
Storm Water Management Plan.
41
Discussion