Most of San Joaquin Valley on state list of critically overdrafted groundwater basins

The state Department of Water Resources on Thursday released a list of 21 groundwater basins and subbasins that are overdrafted, causing land subsidence, chronically lowered groundwater levels and, in the case of the Salinas Valley, seawater intrusion.

Eleven of the areas are in the San Joaquin Valley, the nation’s leading farming region.

“It was a given that we were going to be in a critical deficit area,” said Fresno County Board of Supervisors chairman Buddy Mendes of Riverdale.

A map released by the state shows areas of overdraft extending from San Joaquin County to Kern County, with only two areas around Modesto and Turlock not included.

Regions in “critical overdraft” under the state list must meet the earliest deadlines of the Sustainable Groundwater Management Act that became law in December 2014, and local governments and water entities in the southern San Joaquin Valley are gearing up for it.

Large swaths of Fresno, Madera, Kings, Tulare and Kern counties have overdrafted basins and subbasins. Overdraft is caused by pumping groundwater and not fully replenishing it.

The Kings and Westside subbasins encompass much of Fresno County, plus parts of Kings and Tulare counties, while the Kaweah, Tulare Lake and Tule basins and subbasins encompass much of Kings and Tulare counties.

Madera and Chowchilla groundwater areas are also listed.

Groundwater sustainability agencies must be formed by June 30, 2017, and management plans specifying how to tackle the overdraft, subsidence, water quality and other issues must be written by Jan. 31, 2020. The new law mandates groundwater sustainability by 2040.

Fresno will try to solve its groundwater overdraft problem by using more water from the San Joaquin and Kings rivers and less from wells beginning in mid-2019, said Tommy Esqueda, director of public utilities.

Last year, the City Council approved spending $429 million to build water pipelines and a water treatment plant to make that possible, he said.

“It’ll restore and recharge our groundwater aquifer,” he said.

The Kings subbasin includes Fresno, Clovis, Fresno Irrigation District and other entities.

It’s expected that perhaps five water sustainability agencies will be formed, each with their own plans that will be knitted together to manage groundwater for the subbasin, said Cristel Tufenkjian, of the Kings River Conservation District, which manages water flows in much of the area.

“We’re helping coordinate an overall base effort,” she said.

Boundaries of subbasins do not coincide with the boundaries of counties or irrigation districts, so counties will partner with neighboring counties and irrigation districts to create the agencies.

By necessity, Tulare County will play a leading role in its area, said Tulare County Supervisor Allen Ishida, also chairman of the Tulare County Water Commission.

“We have to be partners to make sure they get done, and play a part in overseeing all of them to be sure they come out with an agreeable plan,” he said.

Mendes said he believes the Kings subbasin can attain groundwater stability, but the Westside subbasin will need water deliveries from the Sacramento-San Joaquin Delta, which have been curtailed as a result of the drought, he said.

“The west side can be very sustainable if delta pumping is allowed,” he said.

Moving water south from the delta faces a high degree of environmental scrutiny.

In Tulare County, groundwater recharge will require water deliveries from the San Joaquin River over many years, Ishida said.

This story was originally published January 21, 2016 at 12:58 PM with the headline "Most of San Joaquin Valley on state list of critically overdrafted groundwater basins."