Keeping Central Valley crops and people safe from floods: a costly proposition

KQED Climate Watch (northern California): Now that the state’s revamped Central Valley Flood Protection Plan (big PDF) is out for public perusal, the question is whether the political will — and the cash — will be there to make it happen.

California's status as an agricultural powerhouse is largely due to the fertile lands in the Central Valley, which are also prone to floods.

The Sacramento and San Joaquin river basins run through the valley and can overflow their banks threatening more than a million people and an estimated $69 billion in assets, according to the report. The current flood management system has been in place for about a hundred years and was designed specifically to keep water from the rivers off the land so that people could grow crops. Now the system has varied uses including conservation of habitat, water supply and water quality. The old system really isn’t up to the job anymore and almost everyone agrees that it will take a serious investment to bring it up to snuff.

“The system itself is beyond its design life,” says civil engineer Mike Mierzwa. “Think of it like an automobile. If you have a car it’s not going to run at top efficiency for 300,000 miles.” Mierzwa, who advises the state Department of Water Resources (DWR) explained to me that, “We’ve put a lot of ‘flood miles’ on the Central Valley’s flood management system and it’s really time for us to go through and find additional capital to actually improve its level of performance to today’s current design standards and needs.”

DWR outsiders are cautiously optimistic about the ambitious report. “This plan is really a framework. It’s not a plan,” says Jeffrey Mount, a geologist who directs the Center for Watershed Sciences at UC Davis. Mount says he considers the plan to be a step in the right direction. “If I could tweak anything it would be that this would be more integrated with other planning processes happening right now,” he told me. He’s concerned that the report punts on some serious questions about how climate change will impact the system and how conservation can be encouraged. The framework does mention those things, but leaves them to be studied more intensely down the road....

The head of Old River along lower San Joaquin River, provided by M.Burns (CADWR) for release into public domain