Editor’s Note: This piece is part of a four-part collaborative series between the University of Denver Water Law Review and the Stanford Environmental Law Journal that studies the public trust doctrine, the stark contrast of its history and development in Colorado and California, and the implications of its extension to groundwater.


When the Environmental Law Foundation filed suit in Environmental Law Foundation v. State Water Resources Control Board in 2011, California had no comprehensive state restrictions on groundwater pumping. While some isolated local groundwater management districts or agencies held authority to regulate groundwater extraction and courts had adjudicated groundwater rights in some regions, most groundwater users faced little or no limitation on pumping. This regulatory void no longer exists. In 2014 the California Legislature passed, and Governor Jerry Brown signed into law, the Sustainable Groundwater Management Act. This legislation institutes comprehensive state regulation of groundwater for the first time in California’s history.

The implications of ELF differ when considered alongside the Sustainable Groundwater Management Act. In this post, we contemplate two issues that the new groundwater legislation poses for applying the public trust doctrine to groundwater as in ELF. First, we discuss how the public trust doctrine’s limitations on groundwater differ from those that will be implemented in groundwater sustainability plans under the new groundwater law. And second, we discuss how the public trust doctrine as applied in ELF could shield the State of California in lawsuits claiming that the Sustainable Groundwater Management Act results in Fifth Amendment takings of private property. Before considering these two issues, however, we first present some background on existing groundwater rights in California and the new groundwater restrictions in the Sustainable Groundwater Management Act.


In practice, California’s judicially-established groundwater rights system has resulted in few practical limitations on groundwater pumping in much of the State. When groundwater aquifers experience overdraft—a condition that occurs when more water is pumped than is replenished over many years—California’s groundwater rights system exclusively relies on lawsuits to adjudicate water rights and limit pumping. Outside of groundwater basins that have undergone court adjudications, groundwater pumping is largely unregulated. The Sustainable Groundwater Management Act is the first comprehensive state regulatory program for groundwater. This Act will be applied on top of three existing types of groundwater rights.

California’s correlative groundwater rights system results in three types of rights: overlying rights, appropriative rights, and prescriptive rights.
• Overlying rights allow landowners over an aquifer to extract groundwater and use it on their overlying land. These water rights are only limited to a quantity that is reasonable when compared to the demands of other overlying rights.
• Water users who use water on land that does not overlie the aquifer are appropriators; appropriators may use “surplus” water, or water in excess of current use that will not result in aquifer overdraft. As with other appropriative water rights, groundwater appropriators in California operate under the first-in-time, first-in-right system. However, appropriators may only legally use water above and beyond that required by overlying landowners—even if overlying landowners start pumping after the appropriator. If a basin is experiencing overdraft, no new appropriators may initiate pumping. Moreover, if overlying landowners begin using more water, lower priority appropriators must stop pumping.
• Prescriptive groundwater rights have also been established in the past in California. These rights are created by the open and adverse continuous use of groundwater in an overdrafted basin for the prescriptive period (five years in California). Other users in the basin must have notice of the overdraft conditions. Under these circumstances, an appropriator may gain a prescriptive right that is exercisable against any other groundwater right in the basin, including overlying rights.


Table 1: “Undesirable results” that must be avoided to achieve sustainability under California’s new groundwater law
(1) Chronic lowering of groundwater levels indicating a significant and unreasonable depletion of supply if continued over the planning and implementation horizon. Overdraft during a period of drought is not sufficient to establish a chronic lowering of groundwater levels if extractions and recharge are managed as necessary to ensure that reductions in groundwater levels or storage during a period of drought are offset by increases in groundwater levels or storage during other periods.
(2) Significant and unreasonable reduction of groundwater storage.
(3) Significant and unreasonable seawater intrusion.
(4) Significant and unreasonable degraded water quality, including the migration of contaminant plumes that impair water supplies.
(5) Significant and unreasonable land subsidence that substantially interferes with surface land uses.
(6) Surface water depletions that have significant and unreasonable adverse impacts on beneficial uses of the surface water.
California’s new groundwater law requires all groundwater basins that the Department of Water Resources designates as high- and medium-priority to achieve sustainable groundwater management. The law relies on local groundwater sustainability agencies to design plans that achieve this sustainability goal. These
plans must achieve sustainable groundwater management by avoiding the “undesirable results” listed in Table 1 over a 50-year time period. By January 31, 2020, local agencies in groundwater basins that experience critical overdraft conditions must adopt their plans. The remaining high- and medium-priority basins must adopt their plans by January 31, 2022. And by 2040, all high- and medium-priority basins must attain sustainable groundwater management. Moreover, the Act provides the State Water Resources Control Board backstop authority to develop and implement plans if a local agency fails to satisfy its sustainability objectives.


The specific nature of limits on groundwater extraction under the public trust doctrine and California’s new groundwater law remains unclear. No governmental agency in California has ever considered, much less satisfied, a public trust duty related to groundwater impacts on surface waters. Similarly, local agencies are only beginning to grapple with developing groundwater sustainability plans that comply with the Sustainable Groundwater Management Act. Nonetheless, the groundwater limitations that would be imposed by the public trust doctrine in ELF differ from those that the groundwater legislation requires.

First, California’s public trust doctrine does not specify particular levels of protection for the environment, navigation, or any other interest protected by the doctrine. Instead, it imposes a common law duty on governmental agencies to balance their impacts on the environment and navigation with other socially or economically beneficial purposes. As the California Supreme Court instructed in National Audubon Society v. Superior Court, before harming interests protected by the public trust doctrine, agencies must simply “consider the effect of such diversions upon interests protected by the public trust, and attempt, so far as feasible, to avoid or minimize any harm to those interests.”

Meanwhile, the Sustainable Groundwater Management Act sets more specific and enforceable requirements for groundwater management. This legislation does afford local agencies substantial flexibility in how they attain sustainable groundwater management. Nonetheless, these agencies or the State Water Resources Control Board must adopt groundwater plans that avoid the six statutorily specified “undesirable results.” Local agencies or the State Board might consider groundwater management options, such as importing water, that allow stressed basins to remain economically productive while also meeting the law’s sustainability goals. And courts and agencies might interpret the requirements to avoid only “significant and unreasonable” adverse impacts from groundwater extraction and use to allow agencies to balance interests. But—unlike the public trust doctrine—the Act does not leave agencies the option to recognize undesirable results from groundwater extraction and take no action to stop them.

The scope of waters protected by the public trust doctrine also differs from those protected by the recent groundwater legislation. First, the recent groundwater legislation applies to a broader set of water resources. The Sustainable Groundwater Management Act regulates impacts on groundwater aquifers, navigable and non-navigable surface waters, and lands that suffer from land subsidence. California’s public trust doctrine, although it may restrict groundwater pumping, is currently tethered to impacts on navigable waters. The ELF court’s decision rested on groundwater pumping dewatering a connected navigable water body—the Scott River—and harming navigation and fish. Another California case, Santa Teresa Citizen Action Group v. City of San Jose, held that the public trust doctrine “has no direct application to groundwater sources.” Nevertheless, the public trust doctrine might still have a broader geographic reach than the Sustainable Groundwater Management Act. While the public trust doctrine applies statewide, the groundwater law only requires sustainability in specified high- or medium-priority basins.

Practically speaking, the ELF decision may result in few changes beyond those that would occur under the groundwater law. Before the Legislature passed the Sustainable Groundwater Management Act, the ELF case seemed like it could lend local agencies the regulatory authority they lacked in statute to limit groundwater pumping. But the groundwater law gives local agencies these regulatory tools, and it already requires high- and medium-priority basins to avoid significant and adverse surface water depletions. It seems unlikely that the public trust doctrine, given its balancing of competing interests and its required link to navigable surface waters, would result in restrictions that the groundwater law would not already require. Professor Dave Owen’s 2012 study of the public trust doctrine’s impacts on surface water rights in California supports this conclusion. Professor Owen found that while the doctrine resulted in limitations on new surface water rights, it rarely limited existing rights. He also found that, because courts often view compliance with environmental statutes as fulfilling public trust duties, the doctrine rarely results in restrictions that would not have happened under those statutes. Consequently, the most substantial practical impact of the ELF decision may be the defense that it may provide against Fifth Amendment takings lawsuits for governmental agencies implementing the Sustainable Groundwater Management Act.


Once the Sustainable Groundwater Management Act goes into effect and local agencies begin imposing restrictions on groundwater withdrawals, unhappy water users may file takings claims under the theory that these restrictions constitute an unlawful confiscation of a vested property right. The Texas case Edwards Aquifer Authority v. Day provides a salient example. There, the Texas Supreme Court held that, despite the fact that the Legislature has empowered local agencies to limit groundwater withdrawals, agencies acting under this authority can still be subject to takings claims. California landowners may decide to initiate similar takings lawsuits once the new regulations are implemented.

If such claims are filed, California agencies may be able to use the public trust doctrine as a defense. As the U.S. Supreme Court articulated in Lucas v. South Carolina Coastal Council, state law may bar a Fifth Amendment takings claim where background principles of state law already limit or prohibit the property interest at issue. Applied here, the agencies’ argument would be that the state merely allowed use of groundwater before the Sustainable Groundwater Management Act went into effect, but that California’s public trust doctrine limits legal protection of that groundwater use.

Pursuant to National Audubon, the public trust doctrine in California bars any party from “claiming a vested right to divert waters once it becomes clear that such diversions harm the interests protected by the public trust.” Even when agencies balance other interests with the public trust and authorize activities harmful to trust interests, under National Audubon, these rights to conduct harmful activities remain non vested. Accordingly, under Lucas, they may not be property interests protected against takings. When coupled with the ELF principle—that groundwater pumping that affects navigable waterways is subject to the public trust doctrine—National Audubon gives agencies enforcing the Sustainable Groundwater Management Act a defense to takings claims.

However, this defense will not apply to all groundwater. As decided in Saint Teresa Citizen Action Group, the public trust doctrine does not apply directly to groundwater sources. Therefore, agencies will not be able to use the public trust doctrine as a defense to takings claims unless they can show that the groundwater being regulated has an impact on navigable waterways.

A recent case in Federal Claims Court in California, Casitas Municipal Water District v. United States, suggested that the federal government cannot use the public trust doctrine as a defense to a water rights takings claim. The case was resolved on appeal on other grounds without reaching the public trust doctrine defense. The trial court, however, held that because the public trust doctrine is a state doctrine, federal agencies could not claim it as a defense. The trial court also wrote that, even if the public trust doctrine applied in Casitas, diversionary interests outweighed the fishery preservation interests protected by the trust. Since state, and not federal, agencies will implement the Sustainable Groundwater Management Act, Casitas does not bar a public trust doctrine defense for the state agencies implementing it. The balancing of interests in Casitas also contradicts National Audubon’s instruction that no entity retains a vested right to perform activities that harm public trust interests.

Accordingly, a court evaluating a takings claim under the Sustainable Groundwater Management Act might hold that the public trust doctrine places a preexisting limitation on groundwater rights, and that this doctrine protects the state from takings claims.


This article can also be found on the Stanford Environmental Law Journal blog, here



Casitas Mun. Water Dist. v. United States, 102 Fed. Cl. 443 (2011), aff’d, 708 F.3d 1340 (Fed. Cir. 2013).

Casitas Mun. Water Dist. v. United States, 76 Fed. Cl. 100 (2007), aff’d in part
and rev’d in part, 543 F.3d 1276 (Fed. Cir. 2008), reh’g en banc denied, 556 F.3d 1329
(Fed. Cir. 2009), dismissed on remand, 102 Fed. Cl. 443 (2011), aff’d, 708 F.3d 1340 (Fed. Cir. 2013).

Dave Owen, The Mono Lake Case, The Public Trust Doctrine, and the Administrative State, 45 U.C. DAVIS L. REV. 1099 (2012).

Edwards Aquifer Auth. v. Day, 369 S.W.3d 814 (Tex. 2012).

Envtl. Law Found. v. State Water Res. Control Bd., No. 34-2010-80000583 (Cal. Super. Ct July 15, 2014).


John D. Echevarria, The Public Trust Doctrine as a Background Principles Defense in Takings Litigation, 45 U.C. DAVIS L. REV. 931 (2012).

Lucas v. S.C. Coastal Council, 505 U.S. 1003, 1029 (1992).

Nat’l Audubon Soc’y v. Superior Court, 33 Cal. 3d 419 (Cal. 1983).

Santa Teresa Citizens Action Grp. v. City of San Jose, 114 Cal. App. 4th 689 (Cal. Ct. App. 2003).

Sustainable Groundwater Management Act (Assem. Bill No. 1739, Sen. Bill Nos. 1168, 1319 (2013-2014 Reg. Sess.).