Waterways staff led the project’s biotic and geomorphic restoration design team, and played a critical role in building consensus for the project by incorporating geomorphically appropriate river enhancement elements into the flood protection design in a manner that achieved the multiple project objectives. Waterways staff developed the engineering design, assisted with public outreach and permitting, and assisted the City with the construction phase. Waterways is currently the prime consultant on a 10-year monitoring plan developed for the project.
St. Helena Comprehensive Flood Protection Plan
Client: City of St. Helena
Waterways staff worked with the City of St. Helena and a team of consultants to design, permit, and construct a multi-objective flood control and habitat restoration project, The project, constructed in 2009 and 2010, provides 100-year flood protection for residential properties along the Napa River, restores important floodplain and aquatic habitat, and improves public access. Specific elements of the project include a geomorphically-based floodplain terrace and associated shoreline restoration involving removal of an existing gabion and rip-rap bank protection structures and replacement with a natural point bar shoreline configuration, bioengineered bank stabilization structures, FEMA certified levee setbacks and floodwall construction, relocation of homes from the floodplain, and approximately 2,500 ft of pedestrian trails with interpretive signage. Design elements were incorporated into project to enhance habitat for a variety of species including salmon and steelhead, river otter, California red-legged frog, and freshwater shrimp.