While a good project to release a higher volume of water when needed, and causing more devastation to the Parkway, this project—which will provide a 200 year level of flood protection—only gets us still less than half way to the gold standard of the 500 year level of flood protection most river cities in the United States have, including Tacoma, St. Louis, Dallas, Kansas City, and still less than the 250 year protection New Orleans had when Katrina hit.
This is a good step, but we need to proceed to 500 year protection with the building of the Auburn Dam, the only project providing that level of flood and Parkway protection.
Flood control project starts
A new spillway at Folsom Dam will boost the facility's ability to move American River water.
By Matt Weiser - email@example.com
Published 12:00 am PST Wednesday, December 26, 2007
More than 20 years have passed since it became clear that the American River needs better flood control. Now the solution to that problem is finally under construction.
Workers began construction on a new spillway at Folsom Dam on Dec. 13. The 1,700-foot-long concrete spillway, adjacent to the existing main dam, will boost its ability to prevent dangerous floods, effectively doubling protection for about a half-million people living downstream.
The spillway will achieve 1-in-200-year protection, or the ability to survive a flood with a half-percent chance of striking in any given year.
Construction is a huge milestone for the project, which has seen as many twists and turns as the American River itself.
"It's actually almost miraculous that things have come together the way they have," said Sacramento Mayor Heather Fargo, also chairwoman of the Sacramento Area Flood Control Agency, a local sponsor of the project. "What it means to the community at risk from the American River is a huge increase in flood protection."
Built in 1955, the dam at Folsom contains eight small river outlets below the water line and eight larger spillway gates on top.
The river outlets can release water at 35,000 cubic feet per second. Maximum releases of 165,000 cfs – the design capacity of downstream levees – can be achieved only once the reservoir rises to reach the larger spillway gates.