Edna Valley farmers, residents, and water companies collaborate on plan to stabilize groundwater basin 

Water wells in the Edna Valley used to be shallow: "You could put a well to 30 or 40 feet. Well that's just kind of unrealistic [now]," Edna Valley Growers Mutual Company President Bob Schiebelhut said.

Some of those shallow wells didn't make it through the last drought, drying up and forcing landowners to drill a little deeper. Now in a new drought, Edna Valley farmers and residents are once again praying for rain, Schiebelhut said. But they're also moving forward with SLO County and the city of SLO on a plan to make their groundwater more drought resilient. The 30-day comment period on a draft of that plan—which covers approximately 20 square miles from the city of San Luis Obispo and Cal Poly to Lopez Reservoir just before Orcutt Road meets Lopez Drive—ends on Sept. 19.

"We committed as a group that we were all going to be collaborative, you know, we're all in this together," Schiebelhut, who grows grapes in the valley, said. "We're going to agree to have all our wells metered. We need to know what's going on. ... We have a pretty good idea of what's going on, but we're going to know a lot more once we get the wells metered."

Metering a system of about 40 wells in the Edna Valley is part of a plan designed to bring its overdrafted groundwater basin back into balance. Currently, about 1,100 acre-feet too much water is being pumped out of the San Luis Obispo Valley Groundwater Basin per year. California labeled the basin as a high priority under the Sustainable Groundwater Management Act (SGMA) and required basin stakeholders to come up with a plan to make it a more sustainable resource.

Passed in 2014, SGMA changed the way property owners interact with the water underneath their properties. Before 2014, groundwater pumping wasn't managed or regulated in the state. SGMA required stakeholders in overdrafted basins to come up with management plans that help make their water basins more sustainable through a combination of projects that supplement groundwater with other water sources and management actions that reduce the amount of water pumped out of the basin.

The Paso Robles Groundwater Basin is in a similar situation, but tension between basin stakeholders split water users into factions wrestling for control over the plan. In the Edna Valley, growers, residents, water companies, and SLO city and county came together to "do the best we can to solve the problem," Schiebelhut said.

"We thought we owned our water and we paid for it, and now we understand that it's going to be treated like a public resource, and that's the way it is," Schiebelhut said. "We're forming a government out here, you know, a new regulatory scheme, so let's do the best we can."

Split into geological halves, the SLO Valley water basin has two separate sub-basins: One runs beneath the city of SLO and some surrounding unincorporated areas, while the other lies beneath the Edna Valley. SLO Deputy Director of Utilities Mychal Boerman said a large bedrock divide restricts the groundwater flow from the Edna Valley portion to the SLO portion.

"Our side of the basin is in really good condition, and at this point, what we believe to be a 700 acre-feet per year groundwater surplus," Boerman said. "The city hasn't used substantial volumes of groundwater since the 1990s. We've been almost completely reliant on surface water for decades now."

While the city gets a combination of water from the Salinas Reservoir (Santa Margarita Lake), Whale Rock Reservoir, and Lake Nacimiento, the Edna Valley relies completely on groundwater. The city also has a wastewater treatment facility, which treats and discharges wastewater into the creek and also uses it for irrigation.

"So, right now, the city is kind of a net beneficiary to the basin," Boerman said.

The city is planning on using groundwater in the future—although there isn't an immediate need—so Boerman said that participating in the long-term sustainability of the basin could help the city balance its use of both groundwater and surface water.

The city of SLO, Edna Valley Growers Mutual Company, Edna Ranch Mutual Water Company, Varian Ranch Mutual Water Company, Golden State Water Company, and the county of SLO formed a groundwater sustainability commission, gathering information from dozens of public meetings and workshops to put the plan together.

"The goal of the commission was to make sure that we could get input from everybody. Single domestic well owners, agricultural operations, environmentalists. We've just been trying to get everybody at the table to come up with a plan that is technically sound ... and hopefully represents the values of our community," Boerman said. "We all kind of have the same goal at the end of the day."

The main goal is to stabilize the water levels, especially in areas that have been consistently low (the Edna Valley sub-basin), county Supervising Water Resources Engineer Mladen Bandov said. With 10 existing well-monitoring sites in the basin, the groundwater sustainability plan calls for introducing 30 more, plus more stream gauges in West and East Corral de Piedra creeks, to help keep on eye on basin conditions and gather data for the future.

Bandov said SGMA requires annual reporting on the basin, and the plan will get reassessed every five years. The potential projects outlined in the plan will be used to enhance supply while the management actions should reduce demand.

Those projects include using State Water Project water for irrigation, for residential use, and to recharge the basin; using the city of SLO's recycled water for irrigation; and working with Sentinel Peak Resources to relocate the spot where it discharges treated water. The company currently treats the water it pumps out of its wells alongside oil and discharges 500 acre-feet of water into Pismo Creek every year. Moving that discharge point 3 miles upstream would enable some of the water to percolate back into the ground as it flows downstream.

Schiebelhut said that Cal Poly is putting the finishing touches on an irrigation study of Edna Valley crops, so that growers can try to reduce water consumption. He said another way that growers are trying to cut back on irrigation is through replanting vineyards, which have a natural lifecycle. His vines, for instance, are 30 years old. The vines he's replanting will have a rootstock that uses 30 percent less water.

"I think I can speak for myself only, but I've learned to be a, you know, better water conservationist through this process, and I think a lot of people have," Schiebelhut said. "We recognize the problem. The other thing we've done is committed to pulling together money for some of these projects."

SLO County Water Resources Engineer Dick Tzou said that the collaborative nature that went this groundwater sustainability plan is a good harbinger for the future.

"We have good science and also, I think, as you know, the community is really behind it—the city, the farmers, the growers, the users in the valley. They're very progressive in looking for projects, and they're really going for it. That's a really positive sign that we're going to be successful," Tzou said. Δ

Reach Editor Camillia Lanham at [email protected].