US 20 PME Hydraulic Engineering and Environmental Mitigation: Lincoln County, Oregon

The US 20 project is a project of statewide significance providing transportation system efficiencies and improved safety that increased economic activity between mid-Willamette Valley and the Oregon Central Coast. The project replaces a ten-mile segment filled with hairpin turns and narrow lanes with a new straighter 5.5 mile segment. Otak was the project hydraulic engineer on the ODOT led project delivery team for Phase 3 & Phase 4, including the design of steep stream channels, slope pipes, outfall energy dissipators, water quality treatment facilities, stormwater flow control facilities, and revisions to the Stormwater Management Plan. Otak was the prime consultant hired to design and then administer construction for Environmental Mitigation (Phase 5) which involved floodplain reconnection, wetland creation, large wood installations, and revegetation at 7 different sites. Otak was the design engineer on a team that delivered Turnkey Environmental Mitigation (Phase 9), including the protection of forested headwater areas, removal of a fish blockage, restoration of a creek, floodplain reconnection and wetland creation.