In an effort to preserve Native American cultural lands, mitigate flood risks and improve coastal habitat for a threatened species, the U.S. Army Corps of Engineers, Seattle District, is reconstructing a sand dune in Willapa Bay near the Shoalwater Bay Indian Reservation.
Construction kicks off July 30 on the $7.5 million federally-funded dune restoration project to provide coastal storm damage protection and prevent wetland erosion. In addition, the project will create and maintain habitat for the Pacific Coast western snowy plover, a small shorebird federally listed under the Endangered Species Act as threatened. Initially, construction was set to begin July 16, but it was delayed because of a successful plover nesting pair this year, producing three baby chicks.
“ Erosion has been destroying the sand spit for years and now it’s threatening the Shoalwater Reservation, including a culturally and ecologically significant wetland area, ” said Joshua Jackson, Corps’ project manager for the restoration effort.
Repair work includes dredging approximately 700,000 cubic yards of sand from a borrow site about 3,000 feet offshore, providing materials to rebuild the 12,500 foot-long protective berm up to 25 feet tall. “ We are also going to grade out the sand in front of the dune, creating a flat sloping beach, prime habitat for plovers which like to nest in open, sandy areas ,” Jackson said.
During dredging, crews will trawl the borrow site to determine Dungeness crab population density. Crews will return to the area next year and add empty oyster shells to the subsurface as a mitigation measure to create habitat and help repopulate the area more quickly. Once the berm is reconstructed, the crest and landward side will be planted with American dune grass as an erosion control measure.
This portion of the two-phase dune restoration project is expected to be complete by late October. The next phase, ecosystem restoration, is scheduled to begin in 2014, allowing time for earthwork to settle.
“ We want to give the area a couple of years to settle in, see how things change behind the berm, what processes take over, and then we’ll look at what we want to do for the restoration effort ,” Jackson said. In addition, the berm will need to be renourished about every five years, dependent upon storm damage.
The Corps consulted with U.S. Fish and Wildlife Service and the Washington Department of Fish and Wildlife on critical habitat needs for plover. Throughout the planning process, the Corps also coordinated with the Bureau of Indian Affairs, National Oceanic and Atmospheric Administration, Washington Department of Parks and Recreation, and the Department of Natural Resources.
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Dredging Today Staff, July 27, 2012; Image: usace