Reliance On Groundwater
While sifting through the red tape associated with water rights may be a task better suited for a lawyer, there are other factors at play here that are more within your control, and a heightened awareness of groundwater use is one of them.
To make do with the water they have available to them, growers in areas where surface water rights are being curtailed must rely on groundwater to irrigate their crops. Groundwater, however, presents its own set of challenges, Aegerter says.
Specifically, Aegerter expresses doubts about the quality of water coming from the water table near the Sacramento-San Joaquin River Delta.
“There’s a shallow water table but it’s not good quality,” Aegerter says. “It’s salty water. I think right now the main concern is what the water quality is going to be — whether it’s going to be salty, and whether that will affect the crops.”
In the Westlands Water District, growers are using a combination of increased reliance on groundwater and fallowing for their water management plans, according to Tom Turini, University of California Advisor in Fresno County.
“The groundwater is lower quality than the district water — with levels of total dissolved salts and toxic ions varying from well to well — but generally higher than ideal, ” Turini says.
“Most growers are already deficit irrigating and using drip irrigation. Fallowing is the primary means of reducing the quantity of water used. Within this very large, historically productive district, there have been reductions in garlic, lettuce, and onion production along with many other crops. Without a surface water allocation in 2015, the percent of land fallowed is very likely to increase.”
Resources For Groundwater Management
In response to the drought and the increasing reliance on groundwater in the state, the University of California (UC) developed its Groundwater Cooperative Extension Program, to provide educational and technical support on groundwater resources and quality issues through different mediums including research projects, a webinar series, and events.
In one of UC’s publications in partnership with the Natural Resources Conservation Service (NRCS), author Thomas Harter, a UC-Davis cooperative Extension hydrogeology specialist, provides tips on sampling and monitoring groundwater.
Harter begins by saying that to get the most accurate analysis, growers must first collect a good sample. An improperly executed sample, or one that has been contaminated as a result of inappropriate transport or storage, may result in an inaccurate test.
The report outlines sampling procedures, beginning with sampling preparations, which include a proper sanitization and calibration of the sampling equipment.
In addition, make sure your field kit includes equipment for preserving sample containers (such as ice, filtration equipment, and reference materials). The full report can be read here: http://bit.ly/1qWjeBD.
According to a study by the Legislative Analyst’s Office, in average precipitation years, groundwater supplies close to 30% of California’s water. In drier years, that number increases statewide to 40%. During years where surface water is scarce, groundwater may provide nearly 100% of irrigation water in certain areas.
Reliance on groundwater will be a reality sooner rather than later for many growers, so proper management is a must. For a full list of resources on how best to manage your groundwater, visit https://groundwater.ucdavis.edu.
