As the Sustainable Groundwater Management Act (SGMA) approaches its 10th anniversary, California is making progress towards implementation—but the 2020–22 drought shows that much work still lies ahead, a new report by the Public Policy Institute of California (PPIC) shows.
The policy brief details how drought poses a particular challenge for SGMA compliance in many farming regions. Increased groundwater use keeps crops irrigated when surface water is scarce, but it can cause undesirable impacts such as dry wells, infrastructure damage from land subsidence (sinking lands), and increased rates of seawater intrusion.
In its report, the PPIC proposes a number of strategies, such as improving groundwater accounting, incentivizing groundwater recharge and demand reduction, and bolstering mitigation measures to help farming regions prepare for drought while improving groundwater stewardship.
Sustainable Groundwater Management Act
Enacted in 2014, during the historic 2012–16 drought, the Sustainable Groundwater Management Act (SGMA) requires local agencies to develop and implement plans to bring their basins into long-term balance by the early 2040s.
Groundwater is a vital source of irrigation and drinking water for urban and rural communities and can impact freshwater ecosystems. Unsustainable pumping—especially during droughts—has created numerous long-term problems, including land subsidence, dry wells, seawater intrusion, and ecosystem harm.
Areas of Progress in Implementation
According to the report, the state and local agencies have made progress in implementing SGMA:
- Clarifying vulnerabilities. Groundwater sustainability agencies (GSAs) and the state are making progress on identifying areas prone to dry wells, subsidence, and seawater intrusion. In the Sacramento Valley, the state has required some GSAs to update their groundwater sustainability plans (GSPs) to better address drought impacts. Some San Joaquin Valley basins risk moving under state management without taking further steps to avoid harm. Efforts are also underway at the state and local levels to better understand how to manage impacts to groundwater quality and surface water—two areas that will be addressed more fully in the five-year updates of GSPs, due in 2025 and 2027.
- Establishing focused management areas for subsidence and wells. In response to recent executive orders and legislation, some GSAs are working with counties to limit the drilling of new irrigation wells in some areas to avoid subsidence and protect drinking wells. Some GSAs in the San Joaquin Valley also are creating zones where pumping is restricted to limit damage.
- Mitigating seawater intrusion. Coastal basins are addressing this issue through demand reduction programs (e.g., voluntary conservation) and basin replenishment efforts, including encouraging growers to substitute pumping with recycled water.
- Speeding up incentives to reduce groundwater use. Basin plans in both the San Joaquin and Sacramento valleys tend to emphasize augmenting water supplies as a preferred approach for ending overdraft. But the recent drought accelerated the launch of demand reduction efforts, such as pumping allocations and fees, groundwater markets, and incentives to strategically fallow land.
- Incentivizing wet-year recharge. A very wet 2023 brought the 2020–22 drought to a close, creating ample opportunities to replenish depleted basins. In the San Joaquin Valley, the PPIC estimates that recharge increased by more than 1 million-acre feet (17%) relative to 2017—a year with similar precipitation. New incentives encouraged growers to divert floodwater to their fields, and agencies that had launched pumping allocations leveraged this system to give credits towards future pumping to growers who engaged in recharge. Innovative recharge efforts have also been expanding in some coastal basins. Such efforts will boost the ability to weather future droughts.
Ways to Improve Sustainability, Resilience
To successfully bring basins into balance, the PPIC stated, local agencies can:
- Continue to refine strategies to avoid or mitigate undesirable results of groundwater use;
- Anticipate drought-induced pumping increases and work to ensure that management strategies adequately offset these increases;
- Improve groundwater accounting, including groundwater allocation and recharge crediting systems, to incentivize both demand reduction and supply enhancement;
- Give growers tools to manage the risks that come with decreased water availability, such as recharge crediting systems and water trading programs;
- Increase collaborative efforts with growers, communities, NGOs, counties, and others to address impacts and allow basins to experiment with new approaches (e.g., incentivizing targeted pumping cutbacks, or recharging in areas that will provide broader benefits); and
- Raise local funding to support these projects.
To read the full policy brief, click here.
