Road Projects Reduce Flooding and Improve Habitat Along Clear Creek

(Port Orchard)-Anyone driving through Silverdale lately can’t help but notice all the construction. Some of that is Washington State Department of Transportation building on and off ramps to connect Highways 3 and 303. The construction along Silverdale Way and Myhre Road is Kitsap County working to reduce flooding and improve habitat in Clear Creek.

Historically, heavy rains caused Clear Creek at Silverdale Way and at Myhre Road to overflow and flood the roadway, local businesses, and impact habitat in the creek. From the Silverdale Way/Clear Creek stream crossing to about 400 ft downstream, the natural floodplain and stream channel of Clear Creek have been confined--the results of past development, road construction and agricultural practices. In years past, large woody debris removal and dredging was done periodically to manage this issue. These practices are no longer allowed. Ceasing of these activities and increased development in the basin have resulted in increased flooding. The four current construction projects funded by Kitsap County’s Surface and Stormwater Management (SSWM) Program, the Kitsap County Road Department, and a Flood Control Assistance Account Program (FCAAP) grant will address these issues.

The first project is on Silverdale Way just north of the Waaga Way (SR 303) overpass where Clear Creek flows under the road through an existing culvert. During heavy rains, the creek overflows and bypasses this culvert. The water then flows south along Silverdale Way to Randall Way and Myhre Road, aggravating an existing flooding problem at these intersections. The replacement of the culvert with a short span, pile-supported bridge and creek channel enhancements downstream of the bridge is designed to eliminate creek overflows.

The second project, partially funded by a FCAAP grant, will increase flood storage and ease floodwater passage within the Clear Creek floodplain, between the Silverdale Way crossing and the Myhre Road crossing. This project will include re-creation of a wetland in an area that was filled in the past. The resulting wetland will improve water quality, reduce the frequency and severity of downstream flooding and provide habitat for a variety of plant and animal species. A landscaped berm will buffer the constructed wetland from traffic noises and other disturbances, enhancing the experience for walkers enjoying the adjacent Clear Creek trail.

The third project is the replacement of the culvert where Clear Creek flows under Myhre Road with a bridge. The bridge will allow more water to flow through this section of the creek.

The final contribution to the reduction in flooding is the completion of the new Hwy 3-Hwy 303 interchange. The current interchange discharges stormwater into the piping network that flows under Randal Way and during large rain events can increase localized flooding near the intersections of Myhre Rd and Randal Way with Silverdale Way. The new interchange will create a large detention system that will meter out runoff and bypass the county drainage system, thereby lessening its impact on the creek and the county’s drainage system.

For questions or more information on this project, call Kitsap County Public Works Open Line at 360-337-5777.

Kitsap County Public Works
The Open Line
(360) 337-5777 or (800) 825-4940
openline@co.kitsap.wa.us