By Lisa McEwen , SJV Water
The state came to Tulare County and gave water managers in the Kaweah subbasin kudos for being proactive on their new plan to stop over pumping in the region.
The head of the state Water Resources Control Board Joaquin Esquivel himself was there to praise the managers.
“We are heartened by the coordination we see in the subbasin,” he said at a workshop held June 27 where Water Board staff explained the ins and outs of the subbasin’s upcoming probationary hearing before the Water Board on Jan. 7. Probation is the first step toward a potential state pumping take over.
In fact, the state was so heartened by changes made in Kaweah’s new groundwater plan, it may negate the need for that Jan. 7 hearing entirely.
“We may change our probationary recommendation if we see progress toward these deficiencies and acknowledge the positive momentum of the Kaweah agencies,” said Natalie Stork, Water Board engineer.
But here’s the catch.
One of the deficiencies listed by the state was too much subsidence, or land sinking.
And, according to a 30-minute presentation at the workshop, Kaweah’s water managers don’t see subsidence as a problem their region has control over.
That’s a Tule subbasin problem, the water managers insisted. The Tule subbasin is sandwiched between Kaweah to the north and Kern County to the south.
Historically, Kaweah growers haven’t been the culprits behind subsidence along the Friant-Kern Canal. To the extent there is sinking along Kaweah’s southwestern border, that’s coming from the Tule subbasin, Kaweah water managers said.
A graphic presented at the workshop by Kaweah managers was stark.
It showed ground displacement, subsidence, as minimal from 2015 to January 2023 along the Friant-Kern Canal as it travels through several subbasins, including the Kings in Fresno County and the Kaweah in northern Tulare County.
Then the bottom suddenly drops out – literally and figuratively – as the canal passes through the Tule subbasin in southern Tulare County. The graphic shows sinking of up to five feet in that time frame. When the canal reaches Kern County, subsidence is, again, shown as minimal.
Consultant Derrik Williams, a hydrogeologist, explained the Kaweah groundwater sustainability agencies coordinated with Tule managers and agreed that no more than seven feet of subsidence will be acceptable in the western edge of the subbasin until 2040.
To accomplish this, Kaweah landowners, many of whom are totally groundwater dependent, must stop extracting from the lower aquifer, which sits under Corcoran clay, and switch to the upper aquifer.
“The GSAs are taking a hard line,” Williams said. “This is going to be difficult to achieve but it has to be our goal.”
Because some subsidence is already “baked in” to the system, he anticipates an average sinking across the basin of 3.1 feet until 2040. Beyond that, the goal is zero subsidence.
The data that water managers have gathered in their effort to comply with the Sustainable Groundwater Management Act has bolstered their confidence in how groundwater flows through the region. The managers ran groundwater flow models 97 times until they determined exactly how to reach sustainable management of the aquifer.
“The takeaway is, after 13 years of hard work, we are able to use a model to show our groundwater overdraft will reduce by 2040 to zero, and it even predicts a surplus of water into the future,” said Aaron Fukuda, interim general manager of the Mid-Kaweah Groundwater Sustainability Agency.
The new Kaweah plan submitted to the state June 13, also addresses the state’s other concerns in their region: Domestic wells going dry because of plummeting groundwater levels; poor water quality; drying wetlands and more.
“We’ve come a long way, and we still have a long way to go,” Fukuda said. “We know our path is right in front of us and we need everyone to stay on that path with us.”
Water Board staff is reviewing the new plan and, based on their findings, may cancel, delay or move forward with Kaweah’s probationary hearing, which is set for Jan. 7.
If the hearing remains on that date, Water Board staff will release final deficiencies and a draft recommendation in December.
SJV Water is an independent, nonprofit news site dedicated to covering water in the San Joaquin Valley, www.sjvwater.org. Reach us at sjvwater@sjvwater.org
