The project consists of prioritizing the replacement of a series of eight culverts located along Seabeck Creek, Kitsap County, WA. These culverts not only fully or partially block fish passage, but also are the single largest geomorphic constraint to floodplain and channel function in the system. These geomorphic constraints limit the ability of the stream to access it's floodplain, confine flood waters in the main channel forcing bed scour and severe incision, and limit wood movement. Without restoring these road crossings, there will always be limited success in restoring this watershed.

Seabeck Creek is an Intensively Monitored Watershed (IMW), managed by the State Departments of Fish and Wildlife and Ecology to evaluate efforts to restore the creek's habitat value for fish and improve freshwater productivity. The creek contains a high level of natural ecological function and structure, but lacks large woody material and associated pools, and has road networks crossing the system at about 30 locations in the 5 square mile watershed. The shortage of pools is significant because of the extremely low flows that occur during summer that limit the availability of rearing habitat for juvenile salmon. The watershed and the stream bed are gravelly, rainfall is about 52 inches per year, and the 100 year peak flow is on the order of 424 cfs. A major storm during December 2007 flowed at about 800 cfs, transported a tremendous load of stream gravel into the lower portions of the stream channel, and damaged and overtopped several of the existing culverts.

Eight of these creek crossings have been identified by WDFW as needing replacement to restore fish passage and geomorphic conditions. Engineering design is required to establish current conditions, optimal design alternatives and implementation costs. This information will allow a more full assessment of the costs and benefits of proceeding with restoration of this IMW treatment watershed.


This project can be found in the Recreation and Conservation Office's Project Information System (PRISM) as # 09-1619.