USBR’s Safety of Dams (SOD) programme is continuing a multi-year construction scheme to perform required safety modifications at Folsom in conjunction with the ongoing Joint Federal Project (JFP).
The JFP represents an unprecedented partnership among USBR, the US Army Corps of Engineers (USACE), the Central Valley Flood Protection Board, and the Sacramento Area Flood Control Agency to address the hydrologic risk to Folsom dam identified through SOD evaluations. Hydrologic risk refers to the possible overtopping of Folsom Reservoir’s dams and dikes during an extreme storm event. The JFP will also achieve the USACE’s objective of increasing flood control at Folsom to 1/200-year protection.
As part of the SOD programme, modifications will be made to Dike 5, an earthen embankment feature located between Dikes 4 and 6 on the north shore of Folsom reservoir, near the intersection of Auburn-Folsom Road and Eureka Road in Granite Bay. The principal work to be performed includes the partial removal of the downstream face of Dike 5 in order to add features such as filters and drains to control internal erosion. The filters and drains will be constructed of high-quality imported materials that will be obtained commercially and brought onsite via trucks. Supplemental material will be excavated from a borrow site within the reservoir bottom close to Dike 5.
Site preparation, including trail relocation, development of the contractor use area, and installation of contractor access off Auburn-Folsom Road, will begin this month and continue until approximately 1 September 2008. Principal construction work on Dike 5 is anticipated to begin after this date, with completion expected in Spring 2009. Some construction activities will be limited to certain times of the year to maintain dam safety and operational/recreational requirements.