Napa County, CA – Flood Mitigation

Since the 1970s, Napa County residents have suffered $542 million in property damage alone from flooding. In 1998, the residents of Napa County, California formed a community-based planning process known as the Community Coalition for Napa Flood Management. The plan is a multi-objective watershed-wide plan for flood damage reduction, river and watershed restoration, and economic revitalization.

Project

The plan has a main goal of reconnecting the Napa River to its natural floodplain and maintaining the natural depth-to-width ratio, modeled on the concept of a “Living River.” The project included the removal and breach of levees in order to allow tide to restore the marsh plains. Over 1,000 acres of wetlands have been restored; 11 acres of riverbanks were cleaned of petroleum spills; 5 bridges were replaced; 33 buildings and warehouses were purchased, demolished and relocated, including 9 houses, 53 mobile homes, and the Napa Valley “wine train” tracks; and 900 acres of river adjacent agricultural lands were purchased. Among the impacts of the project is the mitigation of the severity of flood events, as well as the physical improvement of the City of Napa and surrounding environment.

Implementation & Funding

Approximately 75% of the plan has been completed. The U. S. Army Corps of Engineers’ portions – including excavation, setback levees, terrace grading, in-channel work, and railroad bridges – are all in various states of completion. Almost 100% of the local elements were completed. These elements include the cost of lands, easements, and rights-of-way, and relocation of utilities, structures and railroads.

Original estimates for the plan totaled $250 million: $100 million from federal and state government, and $150 million from local taxpayers and the tourists who visit Napa Valley. The community of Napa voted to raise taxes that would fund the necessary resources to implement the plan. The total costs have almost doubled the original estimates for the project, but higher than expected proceeds from the half-cent sales tax and State of California bonds for flood control have managed to keep the local expenditure side of the equation in balance.

Economic Advantage

Together with the mitigation of flood risk and improvement of natural beauty, economic growth is taking place in downtown Napa and throughout the Napa Valley. This economic boom has been associated with an increase in tourism and ecotourism activities, recreational activities and associated services; as well as increased real estate value. Since the beginning of the project, property values have increased by 20 percent with a 20 percent decrease in flood insurance rates.