Benton County, WA Environmental Rules: Coastal Development (2026)

Washington's Shoreline Management Act, RCW 90.58, applies to the Columbia River, Yakima River, and other qualifying waters in Benton County. Development within 200 feet of the ordinary high-water mark falls under the county's Shoreline Master Program, which sets buffers, vegetation conservation, and no-net-loss habitat standards. The Columbia's Hanford Reach and its shrub-steppe banks hold important fish and wildlife habitat, including fall Chinook spawning. Depending on the work, a shoreline substantial development permit, conditional use permit, or documented exemption is required. Hard armoring such as riprap and bulkheads faces strict review, with bioengineered bank stabilization preferred. Building in the floodway and channel migration zone is heavily restricted.