Greater Sacramento, California, is among the most at-risk regions in America for catastrophic flooding, relying on an aging system of levees, weirs and bypasses and Folsom Dam to reduce its flood risk. But that system, just like a chain, is only as strong as its weakest link. Together, the state of California’s Central Valley Flood Protection Board, Sacramento Area Flood Control Agency, West Sacramento Area Flood Control Agency and the U.S. Army Corps of Engineers are working to modernize this system through a variety of levee improvement projects and upgrades to Folsom Dam – designed to strengthen the entire system and work together to reduce flood risk throughout the region.
The Corps’ ongoing Sacramento levee work is mostly included in its American River Common Features Program. The ARCF is authorized by the Water Resources Development Acts of 1996 and 1999 and includes the strengthening and raising of levees, installation of stream-flow gages and improvements to flood warning systems. So far, ARCF work has primarily focused on seepage, stability, and height remediation of levees along the lower American River. Currently-authorized work is scheduled to be completed in summer 2015. In March 2015, the Corps released a new draft study, the American River Common Features General Reevaluation Report, recommending Congressional authorization for additional improvements throughout Sacramento’s flood infrastructure system, including further levee improvements and widening the Sacramento Weir and Bypass to increase the resiliency and flexibility of the system.
A new auxiliary spillway at Folsom Dam is under construction, and raising parts of the existing Folsom Dam and dikes surrounding the reservoir currently being designed.
Another part of this multi-faceted program is improving a 42-mile ring of levees around the Natomas Basin. Some of the needed levee work has already been completed by the Sacramento Area Flood Control Agency and the California Central Valley Flood Protection Board, under close coordination with the Corps. The Corps’ work to complete the remaining improvements was authorized by Congress in 2014, and is being designed.
A series of levee improvement projects in West Sacramento by the West Sacramento Area Flood Control Agency is also underway, with a Corps study recommending participation in those and further improvements nearing completion in 2015.