Action That Is Long Overdue

by William Martin & Charming Evelyn

Let’s discuss groundwater!

You can find many definitions of groundwater – it is basically water stored underground through millennia via the process of snowmelt and rain seeping through the porous earth to an aquifer. Groundwater fills the spaces between rocks, gravel, and soil beneath the earth’s surface. Groundwater is normally fairly pristine because of the filtering it undergoes in reaching the aquifer. However, with industrialization we have contaminated many of our groundwater sources.
Some of those contaminants occur naturally but most are man-made. e.g., pharmaceuticals and beauty products, industrial solvents, toxic chemicals, motor oils, nitrates (fertilizers & pesticides), PFAS/PFOA/PFOS compounds used in fire-proofing products, human waste, other hazardous waste (many in storage tanks), fracking fluids, micro-plastics, tire dust, road salts, and intruding seawater caused by over-drafting (salt water intrusion).
Groundwater depletion is primarily caused by the over-pumping from the aquifer. This leads to land subsidence (surface land falls/drops), lowering of the water table, increased costs as you have to drill further and further underground to reach water and then pump it back up to the surface. This also reduces water surface supplies – groundwater and surface water are connected, you reduce one, then you reduce the other. Last but not least salt-water intrusion will occur in coastal areas when salt water moves into the space left behind by the overdraft of the aquifer.

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Land subsidence in the San Joaquin Valley by year. Photo: USGS

What is the California Sustainable Groundwater Management Act (SGMA)?

California was one of the last states in the nation to regulate groundwater. In September 2014, Governor Jerry Brown stewarded in a new era by signing major groundwater management legislation, the Sustainable Groundwater Management Act (SGMA).1 For the first time in its history, California had a framework for sustainable, groundwater management - “management and use of groundwater in a manner that can be maintained during the planning and implementation horizon without causing undesirable results.” SGMA empowers local agencies to form Groundwater Sustainability Agencies (GSAs) to manage basins sustainably, and requires those GSAs to adopt Groundwater Sustainability Plans (GSPs) for crucial groundwater basins in California. Groundwater is a critical part of California’s water storage. Basins are grouped high, medium, low, and very low priority.

Why was SGMA passed?

More than 40% of Californians rely on groundwater for part of their water supply, and many small to moderate-size towns and cities are entirely dependent on groundwater for their drinking water systems. According to the Department of Water Resources (DWR), California’s groundwater basins have the capacity to hold somewhere between 850 million and 1.3 billion acre-feet. In comparison, surface storage from all the major reservoirs in California is less than 50 million acre-feet.2
Because of historical groundwater overdraft and the resulting land subsidence, water users switched to using surface water when the Central Valley Project and the State Water Project were completed in the late 1960s. However, groundwater pumping and overdraft became more severe as water demand exceeded the available supply. Satellite imaging published by Jay Famiglietti, of the University of California Center for Hydrologic Modeling and by others, reveals that the Central Valley lost approximately 25 million acre-feet of stored groundwater during the period of October 2003 to March 2010.
The state’s most significant groundwater use occurs in the San Joaquin Valley, Tulare Lake, Sacramento Valley, Central Coast, and South Coast. The Tulare Lake region alone, in the southern San Joaquin Valley, accounts for more than one-third of the state’s total groundwater pumping, according to the Department of Water Resources (DWR). Although desert communities may use smaller quantities of groundwater, many are entirely dependent on these sources.
Groundwater reserves that could be a critically needed resource in times of drought for farms, urban customers, and ecosystems are being depleted at a rate of 2-to-2.5-million-acre feet per year (AFY), though some estimates taking a shorter time period put the depletion rate much higher, as high as 4.4 million AFY. The problem is especially critical in the San Joaquin Valley. It is estimated that groundwater reserves are shrinking by 2.5 million AFY in the Central Valley. An acre-foot is a football field with approximately one foot of water.
The State Water Board estimates that more than 30% of California’s water for agriculture and urban use is pulled from the ground and reliance on groundwater increases to 60% during dry years when surface water supplies shrink. Agriculture uses 80% of our water supply.

How does SGMA work?

The foundation of the Sustainable Groundwater Management Act (SGMA) is that groundwater is best managed at the local level, and the State's primary role is to provide guidance and support through the DWR. SGMA defines a “local agency” to mean a local public agency that has water supply, water management, or land use responsibilities within a groundwater basin (see Wat. Code, § 10721(n)). Any local agency or combination of local agencies overlying a groundwater basin is eligible to become a GSA for that basin. The State Water Board addresses GSA eligibility questions on its Groundwater Management Program website.3
SGMA requires groundwater sustainability agencies (GSAs), to develop groundwater sustainability plans (GSPs), and to manage groundwater for long-term sustainability of medium- and high-priority basins. Low and very low priority basins do not take precedence, though it is encouraged that local municipalities also manage these basins with a GSA.4
The California Department of Water Resources (DWR) has two roles in implementing SGMA:
▪ Regulatory oversight through the evaluation and assessment of GSPs
▪ Providing ongoing assistance to locals through the development of:
o Best management practices and guidance
o Planning assistance
o Technical assistance
o Financial assistance
The Department of Water Resources(DWR) evaluates GSPs to determine if they comply with SGMA, substantially comply with the GSP regulations, and whether implementation of the GSP is likely to achieve the sustainability goal for the basin. DWR’s evaluation and assessment is based on criteria outlined in the GSP Regulations.5 DWR evaluates GSPs within two years of their submittal and issues a written assessment.
The Groundwater Sustainability Plan (GSP) will determine how much groundwater will be used, monitor water quality, land subsidence, storage capability, seawater intrusion, interconnected surface water, and will establish limitations of use to maintain a viable aquifer within a 20-year period. Each GSA will determine their course of corrective action based on the minimum requirement set for each basin. Outside influences are dry/wet years, supply and demand, condition of basin, and groundwater replenishment projects.

What has been accomplished so far under SGMA?

As stated by DWR in March 2022: “January 2022 marked two major SGMA milestones. First, DWR completed 20 basin-wide assessments, predominantly from the most critically overdrafted basins in the San Joaquin Valley, which included reviewing a total of 42 plans that were submitted to the state in 2020. And second, all of the remaining medium- and high-priority groundwater basins responsible for submitting plans by January 31, 2022, met the statutory deadline.” Currently, DWR’s SGMA Portal site shows that there are 142 groundwater basins for which GSAs have been formed, comprising 351 unique local agencies.
In March 2023, DWR announced decisions for 12 GSPs that are deemed critically overdrafted. Six were approved and the other six deemed inadequate and referred to the State Water Board. Inadequately managed GSAs are referred to the State Water Board for intervention and correction, until the local GSA can do so adequately. It’s important to say so, because this makes SGMA different from other groundwater law.
Under SGMA once a GSA has been approved locally, they must enact their plans immediately, regardless of State intervention. Overdrafted basins do receive funding to enact their plans, including technical help from DWR.

Challenges to implementation of SGMA

From the beginning there were some challenges for Tribal and under-resourced communities to actively participate in the planning process. The UC Davis Report, Implementing SGMA: Results From Stakeholder Survey, reports: “SGMA participants have little trust in SGMA’s capacity to achieve environmental and social outcomes, which is key for its success.” The report continues: “Perceptions of adequate representation for agricultural interests, disadvantaged communities, and tribal groups were 65%, less than 50% and about 30% respectively. This is predictably supported by GSA data which shows that only 12% of all GSAs have included non-agency groups such as private pumpers, disadvantaged communities, and tribal members in their decision-making boards.”
The Journal of the American Water Resources Association6 (2021) mirrored the 2019 report and found the two most common obstacles to organizing GSAs were a lack of trust and too many diverse interests among stakeholders. Once formed GSAs also sometimes struggle to come up with a plan to achieve groundwater sustainability within the two-decade timeframe. The most significant barriers to producing an attainable plan, according to the research, were the lack of financial resources and the state’s requirement to coordinate plans among GSAs in the same region.
The SGMA is an extraordinarily important beginning for ground water management in California. Still, a number of improvements would be desirable. Amendments should guarantee equitable representation on GSA boards, shorter timelines for compliance are needed, and opportunities for the state to intervene in certain circumstances must be set. There might be new legislation that creates an improved framework for aquifer recharge, and finally, new regulations are needed to prioritize management on behalf of domestic well users, small farmers, and groundwater dependent ecosystems.
All of California depends, directly or indirectly on groundwater: urban dwellers, farmers, small communities, and the ecosystems that support wildlife. The time for proactive management is here.

Charming Evelyn has been working on water issues for the last 15 years through the Sierra Club and serves as officer or member on a number of their committees. She also serves as an appointee of the CA Coastal Commission Advisory Group, on Sea Level Rise and Environmental Justice, on the board of the CA Conservation Foundation and on the Steering Committee of Southern California Water Dialogue.

William (Bill) L. Martin joined the Sierra Club San Francisco Bay Chapter Water Committee in 2015, after retiring in 2014. He serves as officer or member on a number of Sierra Club committees, and is also the Sierra Club volunteer member of a coalition of groups fighting to save California’s rivers and the species dependent on them.