California flood plan calls for up to $17 billion in repairs

Gosia Wozniacka in the Associated Press: California water officials recommended a historic investment in the state's aging flood control system Friday, saying more than half of the state's levees do not meet standards and the system needs up to $17 billion in repairs and investment.

The Department of Water Resources' release of the first statewide flood plan follows a call by Gov. Jerry Brown to refocus state efforts on preparing for the effects of a warming climate as floods from a faster-melting snowpack already place increased strain on the state's aging levees.
Officials and experts say the state's flood control system — a piece-meal collection of 14,000 levees and other infrastructure built along the Sacramento and San Joaquin rivers by farmers and local governments over the last 150 years — is no longer adequate.

Once a mostly agricultural region that was lightly populated, the Central Valley where the rivers meet has experienced rapid development and population growth. "The system is based on antiquated technologies, so you have to upgrade it and keep in mind changing societal demands," said Jeffrey Mount, professor and founding director of Center for Watershed Sciences at UC Davis.

Central Valley's flood risk ranks among the nation's highest. About 1 million Californians now live in floodplains and levees protect an estimated $69 billion in assets, including the state's water supply, major freeways, agricultural land and the valley's remaining wetland and riparian habitat, said Mike Mierzwa, senior engineer in the Central Valley Flood Protection Office.

The Sacramento-San Joaquin River Delta is a freshwater source for two-thirds of California's population and irrigates millions of acres of farmland throughout the state. While officials have long known the flood control system was in disrepair, it's the first time they have studied it as a whole, come up with long-term solutions and a priority for investments....

The Suisun Marsh Salinity Control Gates (foreground) span the Montezuma Slough at the Roaring River intake (background). They operate like a heart valve, allowing flow in only one direction. In this picture, the three gates are open to allow the freshwater ebb tide from the Sacramento-San Joaquin Delta to push the more saline Grizzly Bay water out of the slough. US Army Corps of Engineers photo