Ringside: Is California’s Water Infrastructure Ready for Climate Whiplash?

If there is anything that might constitute an overwhelming institutional consensus in California, it’s that we are experiencing climate change, and that one of the consequences will be more rain, less snow, and more so-called whiplash between very wet years and very dry years.

In an average year these days, 30 million acre feet of water flows through the Sacramento-San Joaquin Delta. But nearly half of that water comes down in the form of a melting Sierra snowpack which in an average year holds 15 million acre feet of water. This snowmelt fills the reservoirs and feeds the rivers from April through June. With climate change, so we’re told, the volume of runoff won’t change. But we’ll get almost all of it in the three months of winter. Do we have a system to handle winter flows into the delta that are twice today’s volume?

And if not, for the vast majority who view this scenario as a certainty, why aren’t we building anything? Our farmers need about 30 million acre feet per year; our cities, about 8 million acre feet per year. These requirements have not changed in 40 years, even as farm production has doubled and our population has risen from 25 million to nearly 40 million. This proves that we have done a great job at conservation. But we are not ready for what’s on the way.

Let’s imagine what life in 2070 might be like, with perennial deluges pouring an extra 15 million acre feet into the Sacramento-San Joaquin Delta every winter. If this much more winter rain is coming, could we even just let it flow into the San Francisco Bay? Would the levees hold, when ever since environmentalists put a stop to dredging in the 1970s, silt has accumulated in such volume that delta channels that used to be 12 feet deep are now only 2-3 feet deep? If we don’t dredge, will the levees hold against another 15 million acre feet of throughput?

Suppose the delta holds up. Key levees are hardened, critical chokepoints are dredged. How will water be withdrawn for farm and urban use if the only time high volumes of water can be withdrawn is during winter? Even if the existing state and federal pumps operated at maximum capacity, they would only be able to move 900,000 acre feet per month into southbound aqueducts. Moreover, that assumes the California Aqueduct and the Delta Mendota Canal are restored to full operating capacity.

Will the Delta Conveyance — a 45-mile-long tunnel to move water from the Sacramento River north of the delta all the way to the pumping stations on the south end of the delta  — actually get built? And if so, will it be permitted to operate at full capacity of around 325,000 acre feet per month? And will the existing pumps plus the future tunnel, altogether totaling 1.2 million acre feet per month of maximum capacity, be enough?

And if we can move all that water out of the delta during the three months of winter, where will we put it? Farmers depend on water deliveries during spring and summer, with a big portion of those deliveries coming from melting snow. What if there is no snow, just torrential downpours in the winter months? Where will additional millions of acre feet find storage?

If the Sites Reservoir were built, that would help. As an off-stream reservoir located north of the delta with a planned storage capacity of 1.5 million acre feet, Sites could capture some of the high water in the Sacramento River. South of the delta, two big off-stream, aqueduct supplied reservoirs are San Luis (2.0 MAF) and Diamond Valley (0.8 MAF). But filling these and all the rest would not come close to absorbing a significant percentage of the 15 million acre feet that historically has sat patiently on top of the Sierra peaks as snow.

What about California’s massive coastal cities? How will they store enough water to withstand multi-year droughts? The predicament facing the southern counties in the San Francisco Bay Area exemplifies the state’s failure to prepare. Work to upgrade major perimeter reservoirs, fed with water from the State Water Project, is either grossly over budget or all but abandoned. Anderson Reservoir, built in 1960 with a storage capacity of 90,000 acre feet, began seismic retrofits in 2020, with completion not expected until around 2030. The estimated cost for the work has tripled to $2.3 billion. On the east side of the bay, Los Vaqueros Reservoir was planned to be expanded from its current 170,000 acre foot capacity to 250,000. But as the estimated cost soared from $900 million to $1.6 billion, amid a failure among the partners to agree on how to share the costs, the project died. And in the far south of Santa Clara County, the plan to massively expand Pacheco Reservoir from 5,000 acre feet to 140,000 acre feet has all but died as the estimated cost has soared from just under $1.0 billion to $2.7 billion.

And for all of these planned reservoirs – Sites, Anderson, Los Vaqueros, Pacheco – along with dozens of other surface storage proposals across the entire state, escalating regulations and endless litigation promise to either kill the projects, or add years of delay and billions in additional cost.

There are many solutions, and we need them all. Develop additional ways to divert water out of the delta during winter storms. Distribute excess water during winter into the major aqueducts and permit farmers to bank it as groundwater. Identify paleochannels where quick groundwater recharge is possible and pour water into these aquifers as fast as the rain can fall from the skies. And of course, invest in urban wastewater reuse, runoff harvesting, and desalination. But in all cases, projects that could make a difference face overregulation and endless litigation. As a reluctantly cynical and highly informed observer once told me: “Building it is the easy part.”

Will Californians be ready for the warm, snowless winter deluges that everyone insists are coming? As it is, we rely on water projects that were mostly completed fifty years ago. Projects that could never be built today. None of them would make it through California’s gauntlet of bureaucracies and courts.

Today we have to build and upgrade water infrastructure on the scale and with the urgency that previous generations did without hesitation. The climate activists who run our state legislature need to have the courage of their convictions. They need to support massive investment to adapt to what they are so certain is coming our way.