Reductions in water supply from major water sources like the Colorado River and the Sacramento‐San Joaquin Delta watershed have made water conservation and management issues even more of a focus for California policymakers. Furthermore, climate change is expected to exacerbate water supply shortfalls due to extended periods of drought and lower stability of Sierra Nevada and Cascade Range snowpack, which replenish the Sacramento-San Joaquin River Delta. The San Joaquin Valley region is at the nexus of water issues in California. The San Joaquin Valley is home to a rapidly growing population, critical statewide water infrastructure, highly productive agriculture, and severely impacted groundwater basins.
Since 1983, local water suppliers with greater than 3,000 service connections have been obligated by the State to address water supply and conservation planning through the preparation of an Urban Water Management Plan (UWMP). This plan must assess the reliability of water sources into the future, describe demand management measures and water shortage contingency plans, report progress toward meeting a targeted 20 percent consumption reduction by 2020, and discuss the use and planned use of recycled water.
In September 2014, the State enacted the Sustainable Groundwater Management Act (SGMA) to strengthen local management and monitoring of groundwater basins most critical to the state’s water needs. SGMA empowers local agencies to adopt groundwater management plans that are tailored to the resources and needs of their communities.
Groundwater overdraft. During dry years, groundwater contributes around 46 percent of the statewide annual supply and serves as a critical buffer against the impacts of drought and climate change. Many rural municipal, agricultural, and disadvantaged communities rely on groundwater for all their water supply needs.
Continued drought conditions increase dependence on pumped groundwater for rural, urban, and agricultural use as water supply from other sources dwindle. Over-reliance on groundwater can lead to over-drafted aquifers which can in turn lead to a host of negative consequences. These impacts include severe water quality impairment, damaging land subsidence, household and rural community wells going dry, and desertification of local ecosystems. Maintaining balance between the rate at which a groundwater basin is pumped and the rate it is recharged by surface water is critical to guaranteeing continued use of these resources.
Water quality. Increased agricultural, industrial, and urban development has caused a significant increase in salts and nitrate levels found in San Joaquin Valley soil and water resources. These elevated concentrations make many key water resources unusable for agriculture and unsafe for drinking or bathing. The Central Valley Water Quality Control Board is responsible for regulating discharges of industrial and agricultural salts and nitrates as well as enforcing the implementation of best management practices to reduce nitrate flows from non-point sources like farms and feedlot operations.
Funding for groundwater sustainability. California DWR is responsible for awarding grants for groundwater sustainability planning efforts or implementation projects including:
- Geophysical investigations of groundwater basins to identify recharge potential;
- Early implementation of existing regional flood management plans that incorporate groundwater recharge; and
- Projects that would complement efforts of a local GSP that provide for floodplain expansion to benefit groundwater recharge or habitat.
Grant awards are funded by the California Drought, Water, Parks, Climate, Coastal Protection, and Outdoor Access For All Act of 2018 (Proposition 68; SB 5) and the California Budget Act of 2021 (SB 170). These legislative acts have made approximately $300 million available to support groundwater sustainability efforts in critically over-drafted basins.
Relevant State Law
Sustainable Groundwater Management Act (SGMA), Government Code Section 10729. requires local agencies to form groundwater sustainability agencies (GSAs) for high- and medium-priority groundwater basins. GSAs develop and implement groundwater sustainability plans (GSPs) to mitigate overdraft within 20 years.
Urban Water Management Planning Act California Water Code Sections 10610 – 10656 and Section 10608, requires urban water suppliers to review and assess the reliability of water sources over a 20-year planning time frame and report progress toward meeting a targeted 20% reduction in per-capita (per-person) urban water consumption.
Adequate Infrastructure Capacity Government Code Section 65583.2(b)(5), requires that housing element sites inventories must address existing or planned water, sewer, and other dry utilities supply, including the availability and access to distribution facilities.
Urban Water Use Efficiency Standards, Senate Bill No. 606 (SB 606) (2018) and Assembly Bill No. 1668 (AB 1668) (2018), establish the authority of the State Water Resources Control Board (SWRCB) and the Department of Water Resources (DWR) to set long-term urban water use efficiency standards and requires additional analyses to be included in UWMPs.
Water Supply Assessments, Senate Bill No. 610 (SB 610) (2001) and Senate Bill No. 221 (SB 221) (2001), together require public agencies to determine whether adequate water supply exists for large development projects as part of the environmental review process under CEQA. Public agencies may request water supply assessments (WSAs) from a water supplier that evaluates whether the provider can meet the increased demand of the development over a 20-year period.
Of the 45 city and county planners interviewed, 59 percent of respondents considered available water supply to be a moderately to extremely important constraint to housing production. In the coming years, it will be critical for the San Joaquin Valley region and local jurisdictions to consider how to balance the goals of groundwater sustainability and accelerated housing production.
US EPA. Conservation and Efficiency as an Alternative for Water Supply Expansion. This document from the EPA reviews best practices for water providers and State and local agencies to reduce consumption and leakage of water supply systemwide with the goal of reducing the need to develop new water supply.
California DWR. Best Management Practices and Guidance Documents are guidance documents and best management practices (BMPs) to assist local GSAs in planning for and achieving groundwater sustainability in their management basins.
California DWR. Future Scenarios of Water Supply and Demand in Central Valley, describes the approach, methodologies, and results of applying WEAP Central Valley Planning Area model to estimate future water demands. This large-scale overview estimates future water supply and demand as the Central Valley continues to develop and climate change impacts the availability of fresh water in the valley.
California DWR. SGMA Assistance and Engagement, Cal DWR, Planning assistance and public engagement facilitation to support GSAs in creating Groundwater Sustainability Plans.
California DWR. SGMA Technical Assistance, Data and Tools, Cal DWR. Technical assistance and a variety of tools to support GSAs in understanding their groundwater basins and creating Groundwater Sustainability Plans (GSPs).
US EPA. Protecting Water Quality from Agricultural Runoff. Primer on non-point source (NPS) pollution from the EPA outlines the agricultural causes of diminished water quality and provides links to resources to assist jurisdictions to manage agricultural runoff and improve water quality.
California Water Boards. Groundwater Quality Protection Strategy for the Central Valley. A strategy intended to provide a long-range planning document that defines the regulatory programs to be enhanced and identify ways to expand on all partnering opportunities to protect groundwater quality.
California DWR. Sustainable Groundwater Management Grant Program. The SGM Grant Program is managed by the Division of Regional Assistance in the Department of Water Resources (DWR). The SGM Grant Program provides funding to GSAs to promote healthy and sustainable groundwater basins through Groundwater sustainability planning efforts, public outreach and education, technical assistance, projects that promote the sustainable use of groundwater.