The Napa River-Napa Creek Flood Protection Project is a Civil Works project of the US Army Corps of Engineers in the city of Napa, California. The Project area includes some 6 miles (10 km) of the Napa River from the Butler Bridge on State Route 29 on the south to Trancas Street on the north. This section is the upper reach of the estuary portion of the Napa River and as such is tidally influenced. The Project also includes improvements to 1 mile (1.6 km) of Napa Creek, the primary tributary to the Napa River. The project is cited as a new way of thinking about flood control due to its "living river" principles.