State Issues First Stormwater Capture Permit
The California Water Resources Control Board on January 15 issued its first temporary stormwater capture permit, allowing the Scott Valley Irrigation District to flood farm fields with storm runoff to recharge groundwater aquifers.
It might seem strange that a permit is required at all for this. If we accept that permits are needed, it then seems odd that none have been issued until now. These are both symptoms of a state that is constantly pushing against its limited water supply.
Stormwater capture has become a big issue this year because groundwater has been severely depleted: first, by years of drought, and second, by decades of unsustainable pumping. Capturing stormwater by temporarily flooding farm fields and other available land is a relatively cheap and easy way to reverse this downward spiral.
This first permit goes to a partnership that includes the University of California, Davis, which is working with the Scott Valley Irrigation District to measure just how much aquifers are refilled by temporarily flooding farm fields.
They plan to divert up to 5,400 acre-feet of water from the Scott River during storms using existing earthen canal systems, and spread it onto as many as 3,475 acres of existing, dormant agricultural fields.
Such permits are considered necessary because California’s surface waters are also, in most years, in a condition of excessive demand. Diverting river water to flood a field and recharge groundwater could mean taking water from some other important purpose downstream, like habitat for endangered salmon, or shortchanging a water right held by another farmer or a city.
So although stormwater once flooded naturally over what is now millions of acres of California farmland, today it is allowed only under prescribed conditions to avoid harming other water users. In short, it will be allowed only when flow measurements provide some certainty that the stormwater is surplus to other uses on the river.
Another thing that’s noteworthy about this permit: the state water board approved it only two days after it was submitted, suggesting the agency is serious about helping water agencies capture storm flows. It expects to issue many more in the weeks and months ahead.
“The predicted high rainfall events associated with El Niño this year provide an opportunity for accelerating groundwater recharge that we so critically need,” said state water board chair Felicia Marcus in a statement. “This is the first of what we hope are many new opportunities for creative thinking and community effort to take advantage of storm flows everywhere we can.”
Reality Check: Will Farmers Get Water This Year?
It’s one of those questions that can only be answered by time. Yet it’s also one that drives anxiety and is speculated on endlessly in the meantime.
The Associated Press brings us that familiar tale of speculation, warning that San Joaquin Valley farmers may get no water this year despite arriving El Niño storms.
That’s an accurate assumption this early in winter, when water managers can’t possibly know whether they’ll have enough to distribute to their agricultural irrigation contractors come springtime. These water buyers, it must be noted, are the lowest on the totem pole among California water users. They hold no water rights, only contracts to buy water if it is available.
So it isn’t any surprise, in January after a fourth-straight drought year, that they might end up with no water deliveries.
Yet the story is making headlines because Westlands Water District, which buys water from the U.S. Bureau of Reclamation, recently warned hundreds of farm-based water customers they may not receive any irrigation water for the third straight year.
District spokeswoman Gayle Holman told the AP this stormy winter has raised hopes that, in the spring, they’ll receive some federal water, even if officials at first announce that there’s none available. But, she said, by that time it may be too late.
“The need for that water is now,” she said. “That’s why the timing is so critical.”
This is the way things play out every year. Water allocation forecasts are made early in winter, and amended monthly as conditions change. In drought years, they always start out low, and if weather and water storage conditions allow, the allocation forecast improves.
Holman also notes that even if they did get better water deliveries early in the growing season, that water would likely be stored in reservoirs to await the hot, dry summer and fall.
She fails to note that this kind of storage is already going on at San Luis Reservoir, a storage facility jointly owned by Reclamation and the California Department of Water Resources that is used to store and deliver water to Westlands farmers and is exported in canals from the Sacramento-San Joaquin Delta. Since mid-December, officials have been pumping water as fast as they can into San Luis Reservoir, adding about 240,000 acre-feet since mid-December.
And diversions from the Delta continue into those canal systems that serve San Luis, even though the U.S. Fish and Wildlife ordered reductions to protect the endangered Delta smelt. Despite this reduction, pumping has not stopped completely, and Reclamation’s share of water storage in San Luis is still increasing.
If nature turned off the tap tomorrow, that stored water might have to be reserved for cities, which is why Reclamation isn’t yet promising farmers any water: Cities are, by law, a higher priority for water during drought. So while it may be too early for promises, Reclamation is already banking all the water it possibly can in hopes of serving its farming partners if conditions improve.
Top image: Helen Dahlke, a professor in the UC Davis Department of Land, Air and Water Resources, examines an alfalfa field in Siskiyou County that will be flooded to recharge groundwater. The state issued its first temporary storm water capture permit as part of a project Dahlke is working on with the Scott Valley Irrigation District. (Tiffany Kocis, UC Davis)