- The Kings, Kaweah, Tule and Kern GSAs have approved Groundwater Sustainability Plans and Coordination Agreements
- Farmers should know within a year or two how much they can pump
- In the Tule subbasin, some GSAs plan to use an accounting system of groundwater credits allocated to landowners
- Funding for recharge projects will require landowners to vote on property assessments
“How much water can I pump?”
CREDIT: KINGS RIVER CONSERVATION DISTRIC
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Farmers in the San Joaquin Valley are asking this very basic question because the Sustainable Groundwater Management Act, which requires groundwater resources in California to be sustainable by 2040, is officially starting to phase in.
For most farmers there is no firm answer to the question.
Irrigation district managers say they’ll have answers in a year or two as more data is gathered.
Not everyone is being told they must cut back on pumping. But that could change in the next drought.
The immediate emphasis was submitting mandatory plans to the state by the end of the January.
In critically overdraft regions, each Groundwater Sustainability Agency — the new regulatory layer created under SGMA — was required to file a Groundwater Sustainability Plan with the Department of Water Resources by Jan. 31, 2020.
Also due at the end of the month: A Coordination Agreement detailing how the GSAs in each subbasin will cooperate to achieve the goal of groundwater sustainability.
Each agency in the Kings, Kaweah, Tulare and Kern subbasins of the larger Tulare Lake Basin has approved their GSPs and Coordination Agreements. No small feat either by the way.
Each Groundwater Sustainability Plan includes a “water budget” of all inflow, outflow and estimated groundwater overdraft for the subbasin.
Here are some highlights:
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The Kings subbasin has an average annual overdraft of 122,000 acre-feet per year.
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The Kaweah subbasin has an average annual overdraft of 77,600 acre-feet per year.
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The Tule subbasin has an average annual overdraft of 115,300 acre-feet per year.
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The Kern subbasin has an average annual overdraft of 324,326 acre-feet per year.
The Two Knobs of Water Demand and Supply
To keep the groundwater overdraft from worsening, each sustainability plan lays out options for reducing demand and increasing supply — the “two knobs” of water demand and supply.
“We’re going to turn the supply knob first and see what we can accomplish,” said Paul Hendrix, general manager of the Mid-Kaweah Groundwater Sustainability Agency. “Then we’d be prepared to turn the demand knob and ratchet down on the pumping.”
Each Groundwater Sustainability Plan also calls for more monitoring to find out how much groundwater is actually being extracted.
This could mean putting meters on wells (farm wells often don’t have meters), but water managers say by using satellite imagery and evapotranspiration rates they can calculate water use per acre and groundwater pumping amounts in a much less invasive manner.
It’s up to the agencies which options they choose as long as they can show the state they are on the “glide path” to sustainability by 2040.
Recharge Problem — No Water
Nearly every sustainability plan in the Kings, Kaweah, Tule and Kern subbasins calls for more water in wet years to be sunk into the ground locally instead of being diverted elsewhere as has been common in wet years.
For instance, the East Kaweah plan suggests putting Class 2 water from the Friant-Kern Canal into the underground.
But projects may not solve the problem.
“We have specific projects, but will water be available?” said Eric Osterling, general manager of the Greater Kaweah GSA. “If we can’t get the water, we will scale up our management actions.”
Nearly all of the plans envision more water recharge projects being built, although less expensive options such as on-farm flooding also get mentioned.
But recharge projects are expensive.
That’s why Groundwater Sustainabiity Agencies are preparing to hold Prop. 218 elections in which landowners will vote on per-acre tax assessments to fund projects and/or operational expenses of the local Groundwater Sustainability Agency.
But if landowners vote no, the agencies have the authority to raise money by imposing fees on water use.
Tule Subbasin Moves Toward Groundwater Accounting
Three of the six Groundwater Sustainability Agencies in the Tule subbasin are proposing that each landowner be allocated groundwater credits.
The purpose of the credits is to put a cap on groundwater consumption in the Eastern Tule, Lower Tule River Irrigation District and the Pixley Irrigation District GSAs.
“What we are doing is giving (each landowner) an allocation based on sustainable yield,” said Eric Limas, general manager of Lower Tule and Pixley. “If you go beyond what is in your account, you will get notified you are out of compliance.”
Credits will be added to a farmer’s account based on precipitation, recharge from imported water and on farm recharge actions. Credits will be subtracted based on evapotranspiration data.
The credits are expected to give farmers flexibility in the next drought because the credits will have market value.
If there’s a drought and the farmer runs out of credits, the farmer can buy water credits from another farmer who has unused credits.
At least one other agency in the southern San Joaquin Valley, Tulare Lake Basin GSA, is also considering the allocation and accounting system.
Three of the six GSAs in the Tule subbasin are favoring accounting and allocation because the region is especially over drafted, and because the Tule basin is ground zero for where the Friant-Kern Canal has been damaged by subsidence.
“The fact is the Tule subbasin has a target on it because of the Friant-Kern Canal subsidence issue,” Limas said.
Subsidence caused by groundwater extraction is one of the “undesirable results” that SGMA requires agencies to avoid.
Groundwater Marketing Option
Most Groundwater Sustainability Plans list groundwater marketing. Groundwater would be extracted and sold to others within the subbasin.
The State Water Resources Control Board has signaled that it would not oppose groundwater marketing, according to various water managers.
We’ll explore this topic in a future issue.
Land Retirement Is Likely
Land retirement is listed as an option in most Groundwater Sustainability Plans.
As widely reported, a study by the Public Policy Institute of California estimated that 500,000 to 2 million acres in California could be fallowed under SGMA.
It’s still unclear how land retirement or fallowing would take place on the ground.
Ideas include converting farmland to solar panel “farms,” fallowing land and selling the groundwater or credits, or selling ground to a land trust managed by a conservation group.
No matter how it play out, SGMA is officially up and running and will change the way farming happens in the Central Valley.