SLO Valley Basin Groundwater declining; sustainability plan outlines path forward
The San Luis Obispo County Board of Supervisors and SLO City Council are set to approve the SLO Valley Basin Groundwater Sustainability Plan, or GSP.
The sustainability plan details the conditions of the groundwater basin and how it is currently being used. The plan also outlines sustainable ways to manage the water in the future.
The plan is necessary to comply with SGMA, the Sustainable Groundwater Management Act, which is a state law that requires local areas to form Groundwater Sustainability Agencies, or GSAs.
Mychal Boerman is the Deputy Director of Water for the City of San Luis Obispo. He said the city plans to use groundwater in the future, but hasn’t relied on it for years, instead drawing most of its water from local reservoirs.
But Boerman said the Edna Valley area is a different story.
“Out near the Edna Valley where the agricultural areas are, there’s no imported water in those areas," Boerman said. "Those areas are completely fed by groundwater supplies.”
Boerman said as vineyards expanded in the Edna Valley area in the late 1990s, so did the use of groundwater.
“And it appears that that was an unsustainable amount of use,” Boerman said.
He said groundwater levels have continually declined in that area over the last 20 years, so the goal with the sustainability plan is to stop that.
Courtney Howard is the water resources division manager with County Public Works. She said the plan details best practice irrigation strategies as well as a strategy to use water from the State Water Project to help build the basin levels back up.
But, Howard said, if groundwater isn’t restored adequately, agriculture in the Edna Valley area could become subject to water restrictions.
“As a backstop, the GSA’s have the authority to do pumping reduction programs," Howard said. "So, should the levels not stabilize and the state starts indicating that the GSA and the basin users aren’t doing enough, then that’s a fallback as well.”
Howard said the agricultural stakeholders involved with the groundwater sustainability plan are generally supportive and working collaboratively to adjust water use.
Boerman said he anticipates that both the County Board of Supervisors and the San Luis Obispo City Council will approve the plan. The regulatory deadline to submit the plan to the state is January 31, 2022.