The Corps of Engineers and Bureau of Reclamation have revised a flood protection plan for 198.72-MW Folsom Dam to increase protection for Sacramento while costing $660 million less than an earlier plan.
The agencies released a report in June, estimating it would cost $1.357 billion to add an auxiliary spillway and possibly increase the height of the dam by 3.5 feet, with completion by 2014.
A previous, $2 billion flood control and dam safety proposal included building an auxiliary spillway, enlarging and adding outlets, and raising the height of the dam seven feet. That project would not be complete before 2023.
The Corps, BuRec, Sacramento Flood Control Agency, California Department of Water Resources, and California Reclamation Board are collaborating to integrate enhanced flood protection measures at Folsom into the Joint Federal Project, while reducing dam safety risk. The Corps is responsible for flood control. BuRec is responsible for the safety and operation of Folsom Dam.
Report sees lower cost, quicker completion
The report concludes schedule reductions and cost savings in the new plan would provide the public the benefits of flood control and dam safety risk reduction sooner, and at a substantially lower cost, than otherwise would be possible.
Consulting engineers MWH last year evaluated the feasibility of building an auxiliary spillway. MWH helped develop a cost estimate for the spillway, and identified construction methods that would allow an early start on the project, on California’s American River.
The Corps and BuRec said they still must perform detailed cost estimates, applicable economic studies to verify benefit-to-cost ratios, and complete environmental compliance of the proposed action. Results of those assessments are to be provided in Corps flood control documents and BuRec dam safety decision documents.
The Senate Appropriations Committee passed a 2007 spending bill June 29 that includes $8.4 million for the Corps’ Folsom Dam work, and $15 million for construction of a permanent bridge to replace a road across the dam that has been closed since the Sept. 11, 2001, terrorist attacks.