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 California 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. United States Army Corps of Engineers logo The United States Army Corps of Engineers, or USACE, is made up of some 34,600 civilian and 650 military men and women. ... Napa is the county seat of Napa County, California. ... The Napa River, approximately 50 mi (80 km) long, is a river in northern California in the United States. ... JUNCTION POSTMILE SR-20 LAK 52. ...

History of Napa River Flooding

The Napa River runs some 55 miles (89 km) from Mt. St. Helena to San Pablo Bay and drains a watershed of about 426 square miles (1103 square km).[1] The River is prone to seasonal flooding from November through April each year. Flooding that threatens lives and property occurs from the city of St. Helena south through the City of Napa. Recorded history indicates there have been at least 22 serious floods on the Napa River since 1865. The most serious recent floods occurred in 2005, 1997, 1995, and 1986.[2] For the volcano in Washington state, USA see Mount St. ... San Pablo Bay is a shallow tidal estuary that forms the northern extension of San Francisco Bay in northern California in the United States. ...

Process of Project Approval

The US Congress authorized a flood protection project in the City of Napa in 1965 but no funding was provided. Needing matching funds at the local level to gain federal funding, local officials attempted to gain voter support twice in the 1970s but tax measures failed. A severe flood in 1986 regenerated interest and the Corps of Engineers was petitioned to reactivate the project. Nine years later the Army Corps of Engineers design was presented to the local sponsor, the Napa County Flood Control and Water Conservation District. This design was not well received, as it relied on traditional flood control measures including straightening the main channel and constructing high floodwalls. Napa City Councilmember Cindy Watter described the COE design as a "gulag." Environmental organizations and regulatory agencies were concerned that the proposed project would increase sediment transport and negatively impact native species, including the anadromous steelhead trout. Locals were concerned that the project would reduce access to the river for recreation and inhibit economic development. [3] The Congress of the United States is the legislative branch of the federal government of the United States of America. ... Napa is the county seat of Napa County, California. ... 1965 (MCMLXV) was a common year starting on Friday (the link is to a full 1965 calendar). ... The Napa River flood of 1986 was the worst flood ever recorded in Napa, California. ... United States Army Corps of Engineers logo The United States Army Corps of Engineers, or USACE, is made up of some 34,600 military men and women. ... Binomial name Oncorhynchus mykiss Walbaum, 1792 The Rainbow Trout (Oncorhynchus mykiss), also called steelhead trout, is a single species of trout native to the Pacific Ocean and in North American rivers and lakes west of the Rocky Mountains. ...

The Community Coalition

Local politicians and interest groups could not support the COE design as presented. Rather than submit it to voters for certain defeat, an ad hoc Community Coaliation formed with the intent of re-working the design into a project with a chance of success. With the US Army Corps of Engineers and the Napa County Flood Control and Water Conservation District hoping to find a workable solutiuon, a series of meetings involving some 25 agencies and 400 individuals took place over a two-year span. Groups taking key roles in the Community Coalition included Friends of the Napa River, Napa Valley Economic Development Corporation, Napa County Resource Conservation District, Napa Chamber of Commerce, California Department of Fish and Game, Sierra Club, Napa Downtown Merchants, and the Flood Plain Business Coalition (also known as the "Red Zone Rangers.") After a prolonged period of design and redesign, a new local sales tax measure was presented to the voters in March 1998. Needing two-thirds support, the measure passed by a margin of 308 votes out of more than 27,000 ballots cast.[4] The California Department of Fish and Game is one of fifteen Environment and Natural Resources Agencies in California. ... The Sierra Club is an American environmental organization founded on May 28, 1892 in San Francisco, California by the well-known preservationist John Muir, who became its first president. ... 1998 is a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean. ...

Living River Principles

Major objectives of the living river design include reconnecting the river to its historic flood plain, maintaining the natural slope and width of the river, allowing the river to meander as much as possible, retaining natural channel features like mud flats, shallows and sandbars, and supporting a continuous fish and riparian corridor along the river. [5]

How it works

The average annual flow of the Napa River is about 1,300 cubic feet per second (cfs) or 36.8 cubic meters per second (cms) through the populated center of the City of Napa. During a 100-year flood, the flow increases to an estimated 41,000 to 46,000 cfs (1,161 to 1,302 cms). That is equivalent to about 20 million gallons (76 million liters) of water per minute. The Napa River-Napa Creek Flood Protection Project employs a combination of traditional and innovative approaches to reduce the flooding threat. In the downstream project area, dikes have been removed and tidal marshalands have been restored; bridges have been replaced to remove obstacles to water flow; riverbank terracing has been done to provide more room for large volumes of water; a dry bypass channel will be excavated to create a shortcut for fast moving floodwaters to pass through the Oxbow area; new dikes, levees and floodwalls will be built; bank stabilization will be used in specific areas; and detention basins and pump stations will be accommodate runoff behind the floodwalls. A one-hundred year flood is calculated to be the maximum level of flood water expected to occur on average once every one hundred years. ...

Awards

The Napa River-Napa Creek Flood Protection Project has received numerous awards including:

• 1998 American Institute of Architects Award
• 1998 American Institute of Landscape Architects Award
• 1998 California League of Cities Helen Putnam Award
• 1999 Outstanding Comprehensive Conservation and Managemment Plan Implementation Project Award from the San Francisco Bay State Estuary Conference
• 1999 Governor's Environmental and Economic Leadership Award from the California EPA
• 2004 Proclamation of Appreciation from the California Regional Water Quality Control Board, San Francisco Bay Region [6]

Reference

• Napa County Flood Control and Water Conservation District