Even to the casual observer, catastrophic flooding is becoming increasingly common across the nation. Over the past 15 years, serious floods have threatened residents of New Orleans, New York and New Jersey, Houston and now the upper Midwest. These events have tremendous significance to residents of the San Joaquin Valley.
Modesto, Stockton and other communities along the Tuolumne and San Joaquin rivers face growing flood risk. It’s time to face this threat – and to solve it.
The U.S. Geological Survey estimates a large flood could cause $725 billion in economic losses and force the evacuation of 1.5 million Californians.
This risk will grow over time. Climate change is turning slow-melting Sierra Nevada snowpack into rainfall that runs off rapidly into our rivers. As a result, the State Central Valley Flood Protection Board predicts that peak San Joaquin River flows will nearly double in the next half century.
While those in San Francisco worry about a large earthquake, in Stanislaus and San Joaquin counties, when residents think about “the big one,” they should be thinking about a flood.
Fortunately, we know how to meet this challenge – starting with these key steps.
First, the State Flood Board should write a master plan to reduce the flood risk to communities along the San Joaquin River. The flood system on the San Joaquin today falls far short of what we need to keep us safe. Outside of Sacramento, the Yolo Bypass provides a large safety valve that allows Sacramento River floodwaters to safely pass the city. We need a plan to provide the same protection for communities along the San Joaquin.
That plan should include an expanded Paradise Cut bypass in the Delta, a smaller version of the Yolo Bypass. This would allow floodwaters to flow through the Delta, instead of piling up against levees in cities like Stockton. The plan should also include multibenefit floodplain projects upstream on the San Joaquin. By giving the San Joaquin more room to accommodate high flows, these projects can reduce flood risk downstream. They can also help to recharge our groundwater and provide habitat for salmon and wildlife. Recent floodplain restoration projects like the Dos Rios project, at the confluence of the San Joaquin and Tuolumne rivers, show that this approach works.
Second, efforts to implement the state’s landmark Sustainable Groundwater Management Act (SGMA) should prioritize floodplain projects that can help recharge our over-tapped aquifers, increase flexibility for reservoir operations, and reduce the flood risk to neighboring farms and cities. State leadership will be required to ensure that California takes advantage of this opportunity.
Third, the state legislature should increase flood funding in its current proposed bond to reduce California’s vulnerability to climate change (SB 45, by Sen. Allen). Although the bond already includes a category for multibenefit flood work, it features only $300 million for these projects – a drop in the bucket, given the flood board’s estimate that an adequate Central Valley Flood Plan could cost $20 billion.
Fourth and finally, Governor Newsom has announced that his administration is developing a California Water Resilience Portfolio, as an alternative to Governor Brown’s narrow focus on the now-abandoned Delta twin tunnels project. Newsom’s portfolio plan should highlight the opportunity for smart floodplain projects to provide a remarkably broad range of benefits – protecting farms and cities from floods, recharging groundwater, restoring fish and wildlife habitat, and even providing new parks and recreation for underserved Valley communities.
In the contentious world of California water, such win-win projects are scarce – and precious. Governor Newsom and our locally elected officials should make this approach to protecting San Joaquin residents a top priority.
With these four recommendations, we can make dramatic progress in protecting local residents from the kind of floods seen elsewhere across the nation.
Mike Machado, a Linden farmer, represented parts of the Northern San Joaquin Valley in the State Assembly and the State Senate from 1994 to 2008. He wrote this for The Modesto Bee.