Merced irrigation officials scramble to fix groundwater plan, as fear of restrictions loom

Officials with Merced-area water agencies say they’re updating a key regional groundwater plan after the California Department of Water Resources said it didn’t go far enough to reach state water sustainability targets.

Last month the Merced Subbasin groundwater plan was one of a handful of plans by Central Valley irrigation districts graded poorly by the state.

Some of those grades were for alleged deficiencies like failing to indicate how to protect water quality, keep drinking water wells from going dry or stop land from sinking further.

A Nov. 18 letter from Paul Gosselin, DWR’s sustainable groundwater management deputy director, said the Merced-area plan didn’t justify the continued lowering of groundwater and subsidence (the sinking of the ground due to water extraction) in the local subbasin.

Now, local water officials say they’re trying to address the state’s comments and fill the plan’s holes ahead of a Jan. 28 deadline.

“We have more wells that are being monitored, and we’ve allocated some money to build some wells where there’s data gaps,” said Lloyd Pereira, county supervisor and chair of the Merced Subbasin Groundwater Sustainability Agency.

Background on the plan

The groundwater plan for the 767-square-mile Merced Subbasin was compiled by three area groundwater entities that region encompasses: Merced Subbasin Groundwater Sustainability Agency, Merced Irrigation-Urban Sustainability Agency and Turner Island Water District #1.

The Merced Subbasin is deemed by the state to be critically overdrafted, meaning more water is being pumped from the ground than can be replaced by resources like rain, melted snow and other natural forms of irrigation .

Each of the state’s 48 groundwater sustainability agencies determined to be critically overdrafted were required to submit plans by January 2020 to reduce groundwater pumping under the Sustainable Groundwater Management Act.

Passed by the Legislature in 2014, the law will take 25 years to fully implement from its 2015 start date, making 2040 the year the law will be fully enforced.

The Department of Water Resources, the state agency presiding over the sustainable groundwater law, responded to each of the plans this year.

Only six plans were approved. Others were given feedback with the designation “Review in Progress.”

The Merced Subbasin agencies wrote in the initial plan that agricultural and urban water use should be reduced by 10% by 2025 and 40% by 2040 to hit the states’ sustainability goal of 420,000 acre-feet of pumped water a year by 2040.

The Merced Subbasin’s current rate of groundwater pumping – 570,000 acre-feet a year – is causing subsidence, or sinking of the land, to occur by a quarter foot to a little more than half a foot a year on average.

Farmers in the Merced Subbasin are asked to reduce their groundwater pumping by 2% — or 15,000 acre-feet a year — from 2020 onward.

Although less than a foot a year might not seem like much for the land to sink, it can sink it enough to cause major damage to infrastructure.

The phenomenon has made other parts of the San Joaquin Valley sink several feet, and officials are still studying the effects of subsidence on the Merced subbasin.

“If we stop pumping, will that stop land subsidence? Maybe, maybe not,” said Pereira. “We just don’t understand how the water moves underground with 100% accuracy.”

Other water issues at play

Water officials are attempting to address water issues with the state on multiple fronts.

Recently the Merced Irrigation District launched a public campaign against a state plan to divert water away from the Merced River.

MID officials say the Bay Delta Water Quality Control plan will reduce the amount of water in Lake McClure by 40%, leading to further water restrictions.

That compounds the already pressing economic concerns irrigation officials in the Merced Subbasin see on the horizon.

“It’s a real double-whammy,” said Scott Stoddard, director of the University of California Cooperative Extension in Merced.

“It has the potential to cause a lot of issues with crops not having enough water that they need, especially in dry years, but almost even in normal years now. It’s going to make it very difficult for growers in the area to farm as much as they want to farm.”

The Bay Delta Plan was introduced years ago by the State Water Board to help improve salmon populations and water quality in the Bay Delta by diverting nearly half of Merced County’s water supply from Lake McClure and sending it north.

It was opposed from the beginning by Merced locals and officials, who said the effort wouldn’t improve salmon populations and that the Bay Delta’s water quality problems weren’t caused by Merced.

Local officials also said the Bay Delta plan would leave growers in the Merced Subbasin with no source of water other than groundwater.

They say it will also increase groundwater pumping and reduce the rate at which groundwater can be pumped sustainably, potentially decimating a county that counts on agriculture for much of its economic activity.

Despite the severe cutbacks in water facing the Merced Subbasin, some said minor to moderate reductions in agricultural output could work to the benefit of local farmers, to a point.

“In theory, with less water, you have less land being cultivated so you have less work,” Stoddard said. “I just don’t know if you can necessarily say it’s a direct linear correlation between 50% less land, 50% less economy. I don’t think that’s probably what’s going to happen.”

Theoretically, Stoddard said, with reduced water and therefore reduced agriculture, the increased price of the agricultural commodities still produced in the Merced Subbasin could be a boost to the farmers still in business.

However, that does have its limits. “If there’s nothing in the reservoir, and also we can’t pump, and we have a draconian reduction in acres as a result of that, like we have this 40% figure or maybe even more, that’s not good for anybody,” Stoddard said.

Local water officials are also looking for other ways to curb groundwater pumping in the run-up to 2040.

One solution involves having growers and farmers in the Merced Subbasin contribute an as-of-yet undecided amount of money that could be used to pay certain farmers in the subbasin to fallow — or retire — their farmland.

Pereira estimates that will be about 40% of agricultural land currently used in agricultural production in the Merced Subbasin.

However, floodwater dispersed by the state could help replenish the water Merced growers lose in the coming years, he added.

Under those circumstances, Merced County groundwater agencies would have to apply to the state for flood water allocations, which might allow for more agriculture than what locals project.

“That’s our goal,” Pereira said. “How we get there, that’s the hard part.”

If the Department of Water Resources deems the Merced Subbasin’s groundwater plan “incomplete” by the Jan. 28 deadline, local water officials have 180 days from the determination to address it.