After more than three years of review, the California Department of Water Resources (DWR) announced that it plans to approve the Paso Robles Groundwater Basin sustainability plan—an important milestone that keeps the North County aquifer under local management.
“It’s a clear green light,” said Blaine Reely, the groundwater sustainability director for San Luis Obispo County. “We now know we can maintain local control and get a whole lot more aggressive in achieving a pathway toward sustainability.”
SLO County and other local agencies, including the city of Paso Robles, submitted the 20-year sustainability plan in late 2019 to comply with the Sustainable Groundwater Management Act.
After it found some deficiencies in the first draft of the plan in 2021, DWR concluded on March 2 that the agencies adequately addressed its concerns—which were that the plan did not properly consider shallow residential wells or the interconnectivity of ground and surface water.
“We spent a lot of effort trying to understand how much risk there is to rural residential wells,” Reely said, “and identified strategies moving forward to provide some relief and protection for those.”
Reely called the state’s decision “a relief.” In the same March 2 announcement, DWR deemed six other basin plans in the state “inadequate,” including Kern County’s. That means the state will intervene in those basins and take over their management.
Now that it’s approved, basin stakeholders can focus on implementation, he said. The urgency level is high: a 2022 basin report showed that groundwater storage in the aquifer declined by 117,100 acre-feet last year (the average annual deficit has historically been 13,700 acre-feet, according to the sustainability plan).
Since 2019, the Paso basin has lost nearly 250,000 acre-feet of storage, according to annual reports.
“We continue to see, in almost all of our key reference monitoring wells, a decline in groundwater levels,” Reely said.
Those declining levels caused more than 20 basin wells to go dry in 2022, according to DWR data. Reely suspects that the number is actually higher, since not every landowner reports their dry wells to the state.
But Reely added that there’s reason for optimism. The above average rains this winter should help recharge the basin.
Local agencies and farmers are also making progress on supplemental water projects, like the city of Paso’s plan to pipe and sell recycled wastewater to local grape growers to use in lieu of groundwater.
“[The city of Paso] is moving toward awarding a construction contract for that first phase [of the pipeline],” Reely said.
SLO County also recently finished a process with Monterey County to revise its contract for Lake Nacimiento water to allow the reservoir to be used for agriculture. Local municipalities that rely on Nacimiento for drinking water never fully use their allocations, Reely said.
“So there’s always surplus in that system,” he said.
Ultimately, though, farmers over the basin will have to cut back on pumping to balance the basin. According to the 2022 report, agriculture accounts for 92 percent of the basin demand, and thanks to the recent drought, the amount of pumping in 2022 was 44 percent higher than it was three years ago.
“We’ve got to reduce agricultural groundwater pumping,” Reely said. “There’s just no way around it.” Δ
This article appears in Mar 9-19, 2023.