DESCRIPTION
The construction of U.S. 101 through Willapa Bay in the 1930s cut off several salmon-bearing streams from their natural terminuses in Willapa Bay and restricted tidal flows to hundreds of acres of tidal wetland on the Bay's shore. The terminus of South Creek, located at the southern end of Greenhead Slough, has been shifted from a probable historical location along Bear River to its current location at the northern end of Greenhead Slough. Greenhead Slough itself is disconnected from Bear River by a driveway levee running from U.S. 101 to a house now owned by WNWR. Tidal flows to the southern end of Greenhead Slough are restricted by an undersized culvert on a BPA access road near the southern end of Greenhead Slough. This project would: replace the undersized BPA culvert with a larger culvert that does not restrict fish access; add a connection (culvert or bridge) between Greenhead Slough and Bear River; reroute the end of South Creek into Bear River through the new Greenhead Slough/Bear River connection; and add LWD to South Creek to address recorded deficiencies in sediment quality and macroinvertebrate diversity.
The construction of U.S. 101 through Willapa Bay in the 1930s cut off several salmon-bearing streams from their natural mouths in Willapa Bay and restricted tidal flows to hundreds of acres of tidal wetland on the Bay's shore, an area now called Greenhead Slough. The terminus of South Creek, located at the southern end of Greenhead Slough, has been shifted from a probable historical location along Bear River to its current location at the northern end of Greenhead Slough. The southern end of Greenhead Slough is separated from Bear River by a dike used as a driveway running from Hwy 101 to a house now owned by Willapa National Wildlife Refuge. Tidal flows to the southern end of Greenhead Slough are restricted by the dike and an undersized culvert on a BPA access road near the southern end of Greenhead Slough. This project will evaluate and design actions to restore 43 acres of estuarine habitat and increase connectivity between water bodies. Possible actions include: add a connection (bridge or culvert) in the dike between Greenhead Slough and Bear River; replace the undersized BPA culvert with a larger culvert that does not restrict fish access; excavate additional channels and lower select areas of marshplain in southern Greenhead Slough, including channels to bypass the BPA culvert and connect the new bridge/culvert and South Creek; and add large wood to South Creek. The project will increase area and function of estuarine habitat and improve riparian habitat.
