D411 - Woodland Creek Drainage Improvements |
What is the Woodland Creek Drainage Improvements Project?
Project Objectives
- Alleviate poor drainage along Woodland Avenue between a detention pond outlet north of 123rd Street East and 102nd Street East.
- Reduce erosion along Woodland Creek. Residents along Woodland Creek have reported channel erosion since 1993. Erosion damages land and degrades aquatic habitat. Sediment fills in the floodplain downstream.
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Why is the Project Needed?
Flooding of Woodland Avenue between 123rd Street East and 102nd Street East occurs due to a rural street drainage system. As homes were built, culverts were placed under driveways. In side view the elevation of culverts creates a zigzag pattern. Some of the culverts have adverse grades (outlets are higher than the inlets).
A low culvert between two higher culverts can trap water, creating a partial obstruction and a backwater effect. Backwater is a pooling of water behind an obstruction. It can lead to flooding.
The detention pond at 112th cannot drain properly because of the inability of the Woodland Avenue drainage system to the north to drain low flows. Woodland Avenue's eastern ditch holds approximately a foot of water before it starts flowing and takes up room in the ditch needed for conveying stormwater. This causes water needing to exit the detention pond to back up into the pond, instead of draining away.
Woodland Creek channel is eroding severely north of 93rd Street East. During storms high volumes of stormwater in the creek and steep grades have eroded deep cuts and destabilized stream banks. This erosion creates sediment that destroys fish habitat downstream. Photo1 and Photo 2.
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Project AlternativesMap
- Create positive drainage along Woodland Avenue and install an energy dissipater at the downstream end of the 84th Street East culvert. Adjust the existing ditch profile along Woodland Avenue from 116th to 104th Street East to allow low water flows to drain. Replace several culverts. Culverts would not be enlarged so volume is not increased. Realign the drainage ditch and pipelines to improve drainage. Install an energy dissipater at the 84th Street East culvert out to lessen erosion at that location. Estimated cost: $500,000.
| PROS |
CONS |
| Less Costly |
Postpones cost of building additional stormwater detention to a later date. |
| Makes the existing detention ponds more effective |
Does not address long-term detention needs |
| Least traffic disruption |
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| Reduces erosion at 84th Street East |
Erosion at other locations not addressed |
- Construct a detention pond in the vicinity of SR-512 (between 112th and 102nd). The Clear/Clarks Creek Basin Plan calls for construction of an additional detention pond in the Woodland Creek drainage area to reduce the volume and velocity of stormwater runoff in Woodland Creek. Detention would reduce stream channel erosion. Estimated cost: $1,500,000.
| PROS |
CONS |
| Provides detention now when less costly |
High cost |
| Additional basin detention provided |
Streambank stabilization at 84th not addressed |
| Reduces peak flows in the creek and erosion potential of the creek |
Very erosive peak flows remain discharged to Woodland Creek |
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Would not eliminate flooding on Woodland Ave. |
- Construct a bypass pipeline. Even with additional detention, the volume of stormwater during severe storms will erode the Woodland Creek channel and potentially undermine retaining walls next to the creek. This can be avoided by laying a bypass pipeline from the pond outlet down Woodland Avenue to a point near 80th Street East. Estimated cost: $2,500,000.
| PROS |
CONS |
| Highest cost |
| Peak flows in Woodland Creek routed around high erosion area |
No additional basin detention provided |
| Protects property adjacent to the creek |
Greatest traffic disruption |
| Eliminates need for driveway culvert replacements at 72nd Ave East |
Would not eliminate flooding on Woodland Avenue |
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Points of Contact:
Al Zehni, P.E. Project Manager
Pierce County Public Works & Utilities, Surface Water Management Division
2702 South 42nd Street
Tacoma, WA 98409
(253) 798-4677
azehni@co.pierce.wa.us
Jeffrey Davidson, Design Engineer
Pierce County Public Works & Utilities, Surface Water Management Division
2702 South 42nd Street
Tacoma, WA 98409
(253) 798-3090
jdavidso@co.pierce.wa.us
Marsha Huebner, Permits and Planning
Pierce County Public Works & Utilities, Surface Water Management Division
2702 South 42nd Street
Tacoma, WA 98409
(253) 798-4662
mhuebne@co.pierce.wa.us
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Clear/Clarks Creek Basin Plan Projects for Woodland Creek Drainage Basin
Table 9.13 WOODLAND CREEK Recommended CIPs |
| ID |
Project
Name |
Project
Score |
Estimated
Cost |
Priority |
| WO-RST01 |
Woodland Creek
Stream Corridor Restoration |
265 |
Segment 1: 490,000
Segment 2: 490,000
Segment 3: 490,000
TOTAL: 1,470,000 |
High |
| WO-SBS01 |
Woodland Creek
Streambank Stabilization
at 84th Street East |
150 |
305,000 |
Medium |
| WO-SBS02 |
Woodland Creek Stream
Bank Stabilization at
80th Street E |
142 |
357,000 |
Medium |
| WO-DP01 |
Woodland Avenue
Flood Control Phase II |
155 |
2,960,000 |
Medium |
| WO-CR02 |
Woodland Creek
80th Street East
Culvert Replacement |
88 |
27,000 |
Low |
| WO-CR01 |
Woodland Creek
& 72nd Avenue
East Culvert
Replacement Project
- 93rd Street East to
96th Street East |
105 |
102,000 |
Low |
| Total Estimated Cost for Woodland Creek CIPs |
$5,221,000 |
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Projects highlighted in grey are related to the Woodland Creek Drainage Improvement Project.
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Project Timeline 2008
- Scoping Project 2008
- Public Meeting on Alternatives 2008
- Decision on Preferred Alternative 2009
- Detailed Design & Application for Permits 2010
- Construction
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