The Napa River Flood Protection Project is located in the city and county of Napa, California. The Napa River drainage basin, comprising 426 square miles, is just north of San Pablo Bay, a part of the San Francisco Bay System, and approximately 40 miles northeast of San Francisco, California.
The Project is implemented along approximately 6.9 miles of the Napa River. Flood management features include channel modifications, a dry bypass channel, levees and floodwalls, bridge relocations, pump stations, utility relocations, building demolition, maintenance roads, and recreation trails. The plan also includes approximately two-thirds of a mile of channel modifications for Napa Creek.
The major flood management feature is channel modification of the Napa River. A geomorphically-based channel design balances 100-year flood protection goals for the City of Napa with the desire to maintain or enhance the river's natural processes and features, including the restoration of floodplain-main channel interaction and riparian and tidal marsh habitats. Because the project goes through the heart of the City of Napa, aesthetics are an important consideration of the project. Floodwalls, vertical walls, bridges and pump station structure will all have a visual impact on the visitors and citizens of Napa. For this reason all of these structures have been considered for appropriate aesthetic treatments and costs to be shared by the Federal and non-Federal sponsor are included in the cost estimate.