Waite Ranch Tidal Restoration Project

Estuarine wetlands are among the most biologically and economically productive ecosystems, and, historically, the Siuslaw Basin was one of the most productive watersheds for anadromous fish in the Pacific Northwest. Since the 1850s, approximately 67 percent of Oregon’s outer coast estuarine habitat has been lost to land development, contributing to drastic declines in salmon and steelhead abundance. In the Siuslaw Basin alone, where agriculture, grazing, and timber practices have degraded and reduced aquatic and riparian habitat, salmon runs are at less than 1 percent of the historic levels that were documented in cannery records on some years.

This project will restore more than 200 acres of riverfront tidal wetlands an estimated six miles of tidal channels, providing climate change resilience and reversing the historic losses of estuarine wetlands along the Oregon coast, which are among the most biologically and economically productive ecosystems on the planet. In addition, the restoration efforts give the Confederated Tribes of Coos, Lower Umpqua, and Siuslaw People citizens a place to celebrate and promote their culture on their ancestral lands. The project is recognized for its ecological significance in restoring critical fish spawning habitat as well as the landscape’s return to its pre-development state and to Tribal stewardship.

ESA assisted the Confederated Tribes of the Coos, Lower Umpqua, and Siuslaw (CTCLUSI), Siuslaw Watershed Council (SWC), and McKenzie River Trust (MRT) to restore tidal processes, historical floodplain marsh, and swamp habitat conditions to the 209-acre Waite Ranch property on the Siuslaw River. The site was previously scrub-shrub and forested tidal wetland, but was then diked to convert the land to pasture.

ESA led conceptual restoration design and preliminary engineering analyses for the site, developed construction documents, prepared permit applications, and are providing engineering and environmental compliance services during construction. Design objectives addressed breach size and location, dike removal, channel restoration, potential flood impacts, roadway embankment stability, and wind-wave erosion potential. The design includes elements to protect the roadway from wind-waves, including a setback dike and vegetated excess fill placed along the interior of the dike to serve as erosion protection. The design also includes a new culvert and tide gate structure at the setback dike, which was designed to meet Oregon Department of Fish and Wildlife (ODFW) and National Marine Fisheries Service (NMFS) Fish Passage Criteria. Engineering analyses by ESA included hydraulic modeling, wind-wave modeling, geomorphic assessments, flood assessment, and bank stability.