California’s reservoirs are brimming with more than 120% of their historical average levels due to the state’s recent rainfall and snowfall, particularly in its northern areas. Nevertheless, groundwater, crucial for irrigation and drinking, remains significantly depleted. Despite several wet seasons and legislation aimed at safeguarding groundwater, over-pumping by farmers has left many wells dry, particularly in the San Joaquin Valley’s rural, low-income areas.
The disparity between surface water abundance and underground shortages is partly due to the lack of infrastructure. While the Newsom administration has funneled millions into groundwater storage projects and devised strategies to mitigate the issue, capturing stormwater before it rushes out to sea remains complex. Often, this requires building pipelines and canals to redirect excess water into permeable areas or constructing berms to contain flooding until it seeps underground. These measures are costly and time-consuming. Additionally, recharging aquifers is a slow process, as evidenced by the fact that past wet years have only temporarily alleviated water shortages.
Governor Gavin Newsom has committed to addressing these groundwater needs. His Water Resilience Portfolio in 2020 outlined plans to improve groundwater recharge, and by 2022 he set an ambitious objective to elevate recharge by half a million acre-feet annually. There have been some successes, with 2023 seeing San Joaquin Valley farmers manage 7.6 million acre-feet into the ground. But inclement years like 2020 to 2022 saw minimal recharge due to extreme drought.
Research, including a recent Stanford University study, underscores the challenges of groundwater recovery. The study noted that only a quarter of the groundwater lost since 2006 has been replenished, highlighting the inability of even wet winters to offset previous losses. Despite permits issued in 2023 to allow significant diversions of water for recharging during floods, bureaucratic delays and costly conditions limited the outcomes.
Some farmers, like Don Cameron from Fresno, have taken proactive steps to restore aquifers. Since 2011, Cameron has increased his farm’s groundwater levels significantly through a self-funded recharge system. Yet, the challenge remains that water replenished by any one landowner benefits neighboring properties too, without a guaranteed return to the original investor, thus deterring widespread investments in similar projects.
In response, some regions have developed systems to credit farmers for water added to local basins. For example, the Pajaro Valley Water Management Agency offers “recharge net metering,” giving rebates according to the water processed through landowner systems. Similarly, the Tulare Irrigation District credits farmers for groundwater returned during more depleted periods.
As the West anticipates an increasingly erratic climate with extreme weather fluctuations, California’s water managers, aware of a projected 10% decline in water availability by the 2040s, focus on bolstering water capture mechanisms. Governor Newsom’s recent orders have allowed for more water to redirect into storage than previous years, yet have also raised ecological concerns regarding impacts on the Delta’s salmon and other aquatic life, which rely on steady river flows.
Despite recent successes in expanding groundwater recharge, long-standing over-extraction has left a legacy of dry wells, predominantly affecting the San Joaquin Valley. Overreliance on groundwater for agriculture has led to significant land subsidence, and recent intensive extraction virtually negates recharge gains. The ongoing drought conditions between 2014-2015 and 2021-2022, combined with recent reports of drying wells, highlight persistent community struggles in historically affected locations.
The challenge of meeting agricultural and urban water demands with sustainable practices remains formidable. With over 140 million acre-feet of available storage below the Sacramento and San Joaquin valleys, efforts to fill these voids face hurdles due to limitations in water conveyance infrastructure. The significant growth of agriculture, especially water-demanding crops, necessitates strategic reductions in actively farmed lands to counterbalance groundwater depletion.
Ultimately, experts stress that while recharge projects improve supply resilience, they alone cannot resolve the breadth of groundwater scarcity issues. Effective long-term management will require disciplined reduction in agricultural water use coupled with robust recharge strategies to sustain California’s water needs across agriculture and communities.
