- The new Beaver Creek estuary provides critical habitat for a range of fish and other marine wildlife.
- Beaver Creek Estuary before restoration.
- The new arch culvert/bridge during construction.
- The project added 1,100 feet of new free-flowing stream and a widened floodplain.
- The stream empties into Puget Sound's Clam Bay and transports sediment more naturally, reducing the need for dredging.
Beaver Creek Habitat Restoration
Sustainable restoration design reestablished a historic floodplain and estuary on US Navy property.
Beaver Creek is a year-round salmon-bearing stream that runs through the US Navy’s Manchester Fuel Depot near Port Orchard, Washington, and empties into Clam Bay in Puget Sound. Since the 1940s the creek and its estuary have been rerouted, blocked by dams and covered with fill. These activities have impaired the natural function of the stream and estuary, severely limiting the salmon foraging, spawning and rearing habitat the stream environs would normally provide.
In 2001 the US Navy began a long-term project to completely restore Beaver Creek from the Navy’s property line to the estuary where the stream enters Clam Bay. GeoEngineers was the lead consultant for the project, under contract to the US Navy.
During the multi-phase design and construction project, GeoEngineers and its subcontractors completely restored six acres of the creek’s lower channel, floodplain and estuary to their pre-World War II conditions.
Upstream, the team planned and designed for the removal of an existing culvert and installation of a 22-foot bottomless arch culvert. The team also removed several existing instream fish weirs, regraded the stream bed and constructed a side-channel flood-pond as over-winter fish habitat.
Overall, the project recovered approximately three acres of downstream floodplain and estuary as active habitat, and the Beaver Creek sub-estuary is now reconnected with the stream channel and Puget Sound.
Approach
The GeoEngineers project team—including hydrologists, geologists, biologists and geotechnical engineers—provided the stream and estuary design, project permitting, construction oversight, and overall project management. To complete the project, GeoEngineers:
- Determined pre-impact conditions, using historical air photos and site drawings
- Removed fill and an old ladder to allow unimpeded fish passage to upper reaches of Beaver Creek
- Created a habitat-restoration design to enable the creek and estuary to change in response to natural processes without losing functionality or requiring frequent maintenance
- Forged highly collaborative partnerships with the Manchester Fuel Depot, Mid Puget Sound Fisheries Enhancement Group, Kitsap County, Suquamish Tribe, US Army Corps of Engineers and the State of Washington
Results
- Re-established the historical floodplain to allow improved natural stream functions
- Provided significant new fish and wildlife habitat by re-establishing the near-shore estuary
- Documented the return of more than 1,500 Coho salmon to the estuary during construction
- Increased fish production in the east Kitsap area of Beaver Creek
- Promoted project awareness and success through cooperative agreements with tribes and agencies
- In early 2012, completed construction of the upper culvert replacement that GeoEngineers designed, completely restoring fish passage for the lower Beaver Creek watershed in Kitsap County.