aquifer at edge of field
The aquifer at the edge of the field. Water oozes from the earth in early spring. Photo By sheris9 / shutterstock

By Christine Souza, Assistant Editor, Ag Alert

Reprinted with Permission from the California Farm Bureau Federation 

Bracing for potentially a second consecutive year of dry conditions, California water officials, farmers and researchers participating in an irrigation conference discussed recharging aquifers with stormwater and increased water efficiency among ways to diversify the state’s water supply.

The 59th annual California Irrigation Institute conference was held virtually last week, in time for the year’s second manual snow survey by the California Department of Water Resources.

During the survey at Phillips Station in El Dorado County, DWR recorded the snowpack at 93% of the average snow-water equivalent—but electronic measurements show that statewide, the snowpack stood at only 70% of average and 45% of the April 1 average.

At the CII conference, keynote speaker Wade Crowfoot, California secretary for natural resources, pointed to recent storms and noted that despite the snow and rain, the state remains in a period of prolonged dry conditions.

“There’s a lot of work that can happen across the state to be better about actually diversifying our water supply,” Crowfoot said, “and we’re going to need to do that, given the implementation of the Sustainable Groundwater Management Act and less reliable supplies from our natural cycle due to climate change.”

The state is focused on building resilience, he said, adding that he believes “there is a lot that can be done to improve our efficiency to help our water go further,” such as capturing more stormwater to recharge aquifers, increasing surface supplies and recycling more water.

“In the agricultural space, there’s great opportunity to get ‘more pop for the drop,’ whether it’s improving the efficiency of irrigation systems or improving the quality and organic content in soil to maximize water retention for the benefit of producing crops,” Crowfoot said.

California Farm Bureau Director of Water Resources Danny Merkley, a CII board member, said California has one water-supply system that needs to be managed for agricultural, urban and environmental needs.

“New water supplies, including treating and reusing urban wastewater, continuing to increase water efficiency on the farm and urban conservation, can ease the pressure on the system for the benefit of all,” Merkley said. “California needs to pursue all options, including new reservoirs both above and below ground, to assure our economic and environmental future.”

The conference included sessions on agricultural and urban water management issues, plus general sessions on topics such as leveraging stormwater as supply, creative approaches to Low Impact Development (managing stormwater to recharge aquifers), measuring and monetizing groundwater recharge, and the use of adaptive management tools from a farmer’s perspective.

During a session on water demand management, Farm Bureau of Ventura County CEO John Krist said groundwater accounts for a large percentage of the county’s agricultural water use, and that water efficiency and conservation have been a way of life for the area’s farmers for many years.

“To some degree, Ventura County got the jump on SGMA by several decades,” Krist said, because roughly half of the irrigated acreage in the county is under the purview of the Fox Canyon Groundwater Management Agency. The agency was established in the early 1980s to regulate groundwater extractions and specifically to address the seawater intrusion near the coast.

“Everybody’s been working under an allocation system for a number of years,” he said. “It doesn’t provide incentives specifically for efficiency, but it disincentivizes inefficiency by charging you a significant surcharge if you go over your allocation.”

Calling the fallowing of farmland “a strategy of last resort,” Krist said Ventura County farmers are further increasing irrigation efficiency by using hydroponic techniques and growing crops that require less water—such as industrial hemp, which he said uses less than half of the water of vegetable crops.

“You can’t make money on $4,000-an-acre ground with $2,000-an-acre crops,” he said.

Glenn Drown, Northern California manager at Lidco Inc., a business that specializes in agricultural drainage tile installation, discussed using tile drains for groundwater recharge.

Tile drains are commonly constructed to remove excess water from the soil to optimize plant growth and increase yields, he said, and the idea of using them for recharge was brought to his attention by an engineer.

“(The engineer’s) idea was to install the lines just as we typically do for drainage, but to change the slope,” Drown said. “I told him this could be a terrific option for farmers rather than retiring the land, building surface ponds and taking property off of the tax rolls.”

Drown said he foresees water districts and groundwater sustainability agencies adopting such projects. He suggested participating landowners could receive compensation or credit for the operation of the system, and a water district and other users could also benefit from the water supply.

Andrew Fisher, professor of earth and planetary sciences at the University of California, Santa Cruz, said use of stormwater for groundwater recharge could improve water quality and supply, and provide a range of additional benefits, including for habitat and aquatic systems.

“Using stormwater can be part of a successful portfolio,” Fisher said. “We would not suggest that it can solve California’s challenges, but it’s a valuable addition to other methods that are applied in order to sustain and secure water resources going forward.”

On the urban side, Danielle Dolan, water program director for the Local Government Commission, discussed Low Impact Development, or slowing the flow of water and allowing it to percolate into the ground. Dolan said this “slow it, spread it, sink it” approach is working in various places in California to achieve multiple benefits.

CII board president Carrie Pollard of the Marin Municipal Water District said the virtual conference intended to “bring agricultural and urban sectors together, to find creative and inspiring solutions to advance irrigation efficiency in California.”