For example, two snowy winters followed by intense heat created a risk of flooding in 2023. State officials decided release Water from Lake Oroville and other reservoirs in Southern California and the Central Valley. Although this helped prevent flooding and sent water downstream, many Californians were upset that fresh water was being wasted. In an attempt to reduce spills, water agencies and irrigation districts made recharge basins to capture rainfall, but it was not enough. Constant overpumping and climate change mean that the aquifers remain depleted to this day.
Its natural recharge process — precipitation that accumulates as surface water seeps through the soil to recharge underground aquifers — can also be disrupted by urbanization or impermeable covers like pavement, said Bruk Berhanu, a senior researcher in water efficiency and reuse at the Pacific Institute.
The study suggests that more managed aquifer recharge (MAR) infrastructure is needed to adequately capture large amounts of water in short periods of time and avoid similar water loss situations.
MAR is an intentional method of recharging aquifers, especially those at low levels. MAR infrastructure, already commonly deployed in California, includes conveyance structures that redistribute water to dewatered sites and injection (spraying water onto the ground or, the more expensive option, infusing water directly into wells).
However, to ensure effective recharge of aquifers, increased monitoring and measurement is required. “Until 2014, producers were not required to monitor or report any water withdrawals or injections into aquifers,” Schwabe said.
Still, California has more monitoring practices than other states, largely because water availability isn’t as big a concern elsewhere, Berhanu said. Monitoring standards vary by state and region. Regulations for urban areas differ from those for agricultural or industrial areas. Drawing on Berhanu’s work, which assessed the country’s volumetric potential for water-use efficiency at the municipal level, he found that “there is no federal regulatory framework for monitoring or reporting. In many cases, water supplies aren’t even metered.”
Even in areas that had regulations, reporting was often infrequent or incomplete; UC Riverside researchers are working to expand the few accurate monitoring systems implemented in Southern California by proactive growers.
In addition, the study proposes voluntary water markets where farmers with a surplus of water can exchange it with another farmer who needs it. It’s a win-win process: the selling farmer gets an extra profit and the other gets much-needed water. “With prices based on scarcity plus shipping costs, such a market would have incentives for storage and efficient use,” Schwabe said in a press release.
Berhanu added that water trading markets may work in some areas but not in others. “You need a very strong governance framework to ensure that all actors are playing by the rules.” The process will need to have better monitoring practices, transparent data and clear external costs, he said. “The more decentralized the way these transactions are done, it becomes very difficult to coordinate the overall benefits of the system at the basin scale.”
The study also mentions the value of reusing wastewater. Historically, wastewater has been treated to an environmental safety standard and then discharged into the ocean or groundwater system. Over time, natural processes will clean it. Instead of waiting for the environment to purify it, water treatment facilities can reuse it for irrigation, commercial use, or water recharge.
Starting in 2023, water treatment plants will be able to purify wastewater so well that people will be able to drink it. “At some point, the water we use will become someone else’s drinking water or irrigation water,” Berhanu said. Whether the wastewater is used for drinking or to recharge aquifers, California plants are expanding their operations to include recycling methods so they can produce a sufficient supply.
“The total volume of water in the world is not changing much. We need to change our way of thinking from focusing on the amount of water available at any given time to trying to better integrate our practices with the entire water cycle,” Berhanu said.
The study goes on to mention numerous efficiency and management-based solutions, such as sustainable farming practices, land reuse and desalination to help the agricultural industry adapt.
“Now is the time to think about the possibilities and opportunities for collaboration between agriculture, municipalities and the environment to invest in smart investments that capture more water and put it in the ground,” Schwabe said.