Groundwater law’s sinking of ag economy may have been overstated

Study of Tule Sub Basin says southern Tulare County will likely fallow less valuable field and forage crops instead of valuable fruit and nut crops, which are the largest employers as well

TULARE COUNTY – As the deadline for local agencies to implement plans to reduce groundwater use approaches, a new study finds California’s landmark legislation may have less of an impact on the local agriculture economy than originally predicted.

A study authored by Professor Michael McCullough on the effect of the Sustainable Groundwater Management Act (SGMA) in the Tule Sub Basin in the Central Valley shows the long-term effect of the ongoing drought and restrictions on groundwater. It says by 2040, the deadline for local agencies to reach groundwater sustainability, the 2014 law will likely result in the loss of some crops, but probably not the more valuable ones, such as fruit and nuts, in the sub basin which encompasses Tulare County south of Tulare to the Kern County line. McCullough, a professor of agribusiness at Cal Poly San Luis Obispo, estimates the Tule Sub Basin will see a reduction of about 3,000 acres in permanent plantings for citrus, about 600 acres in grapes and 5,000 acres in almonds, he explained on a podcast sponsored by the Milk Producers Council of California last month.  

The study, titled “The Future of San Joaquin Valley Agriculture Under Climate Change and SGMA,” assumed a drastic decrease in groundwater pumping of about 226,000 acre feet per year by 2040 but an active water trade effort adding back some 40,000 acre feet per year. An acre foot is about 326,000 gallons of water. This extra supply would come from a combination of recharge, reservoir expansion and water trades.

“We basically changed the entire paradigm of the Central Valley,” said Geoffrey Vanden Heuvel, who hosted the podcast for the Milk Producers Council. “We should have probably regulated groundwater extraction decades ago but we didn’t, so we built an agriculture powerhouse based on the fact groundwater can be extracted without regulation.”

The Tule area has been the epicenter of some of the worst land subsidence due to over pumping, requiring a multi-million dollar expense to rebuild the Friant Kern Canal, which is already underway.

The study has yet to tackle the impact of long-term water scarcity on Tulare County’s top crop, dairy, except to point out that dairies will likely be growing less of their own feed crops, such as hay, alfalfa and corn, for the cows, as they do today. McCullough’s economic modeling predicts silage and grain crops in the Tule Subbasin will drop by about 23,000 and 13,000 acres, respectively. Imported feed will be more common if one can find it. Vanden Heuvel remarked that field crop prices right now are so high it could encourage more planting of crops like hay – fetching $400 a ton now- about a 35% more than a few years ago. “It’s pretty impressive when a truck load of hay worth $10,000 comes by” he jokes. He expects a substantial increase in the price of corn silage. A dairy component of this study is underway.

Also on the podcast was David De Groot, watermaster on the Tule River and an engineer with 4Creeks, which works with many of the GSAs in the Tule Sub Basin. He said this change will impact how dairy farmers manage cow manure currently spread on their own adjacent farm land as fertilizer for silage crops.

“It takes a lot of water to operate a dairy,” De Groot said. “The good thing about dairies is they recycle a lot of that water and have become more efficient of the years.”

He advises dairies to put in water meters or at least begin tracking its evapotranspiration (ET) rates through free, online software to determine how much water they are currently using. He said a good starting point for a Tule GSA is about .5 acre feet of water consumption per acre per year.

“Each dairy farmer needs to be more sophisticated and efficient … and a dairy digester definitely helps move in that a direction,” De Groot said. Dairy digesters work like a stomach, converting gas into solids, or in this case, manure into methane gas. That gas can then be refined into a renewable natural gas and pumped into main pipelines helping residents to heat their homes and to fuel farm equipment.

McCullough said partnerships with the state will be key in protecting agriculture by funding research and development of new agriculture policies and practices. Vanden Heuvel said the state is going to have to take a bigger role in funding water storage and conveyance projects throughout the state. The state took its first step in that regard last month when it released $30 million to aid phase 1 of the Friant-Kern Canal Middle Reach Capacity Correction Project that will rehabilitate 33 miles of the canal affected by subsidence. The canal has lost more than 60% of its conveyance capacity from subsidence caused from over pumping groundwater, making repairs even more urgent than before.

“There is a lot more that needs be done, particularly when it comes to conveyance, to get these waters to the places they need to be in the short windows when they become available,” Vanden Heuvel said.

As for the fate of farmworkers, some are sounding the alarm of some kind of collapse of the San Joaquin Valley’s agriculture workforce with so much land being retired. However, the same study also suggested the impact on the farm labor economy may be more muted since field crops do not employ large numbers of farmworkers like permanent crops. That equates to a loss of about 100 jobs. Citrus orchards in the Tule basin currently employ about 6,612 workers and would likely still employ about 6,000 workers in 2040 after SGMA is fully implemented. That’s not exactly a collapse of the ag workforce predicted by the industry.

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