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.
Client: San Lorenzo Valley Water District
Waterways is assisting the San Lorenzo Valley Water District by leading the design team on the Fall Creek fish ladder and diversion screening project. The project involves retrofit of an existing fish ladder and diversion intake structure to comply with current DFW and NOAA fish passage and screening standards. The design lowers existing intake screens and weirs while also adding two additional weirs downstream of the existing ladder to reduce individual jump heights. Phase one was constructed in 2014 and phase two is planned for the summer of 2021.