Smith Creek Tidal Restoration

Willapa Bay is a significant ecological resource with a community dedicated to its restoration and conservation. Development and levees on the Naselle River floodplain have kept juvenile salmonids from prime rearing habitat and reduced the tidal flux into Smith Creek. Through physical investigation, modeling, alternative analysis, and design, Otak is helping to restore tidal inundation to 100 acres of estuary habitat, as well as fish passage to Smith Creek, a tributary to Naselle River and Willapa Bay. The crossing at the mouth of Smith Creek is formed by an embankment with two 72-inch culverts with collapsed and failing tide gates. The gates will be replaced with a 100-foot-span bridge to achieve unconstrained tidal flux, fish passage, and scour designs. A cross levee will protect nearby private land and roads. We used high-magnitude flood models to assess conditions resulting from climate change and mapped historical channels in the floodplain to improve salmonid habitat. Final design will be completed in 2019, and we are developing permit drawings and grant applications to obtain funding for final design and construction.