A California court has sided with a Southern California water district in a high-stakes case with a Native American tribe over access to groundwater. The ruling follows a 2017 decision that found the Agua Caliente Band of Cahuilla Indians (Tribe) had reserved water rights to groundwater under its lands.


In May 2013, the Tribe filed suit against several Coachella Valley water agencies and asked the United States District Court for the Central District of California (District Court) to declare that the Tribe has federally reserved groundwater rights. Because of the complexity of the issues involved, the parties agreed to split the case into three phases. In Phase I, the Tribe asked the District Court to declare that it holds federally reserved rights to the groundwater underlying its reservation. All parties separately filed motions for summary judgment as to the Phase I issue. The District Court, thereafter, ruled that the Tribe does have federally reserved groundwater rights. These rights were reserved for its benefit by the federal government when it formally recognized the Tribe and created the Tribe’s reservation through Executive Orders in 1876 and 1877. Additionally, the District Court found the Tribe’s rights preempted groundwater rights based on state law because of their origin in federal law.

In its landmark decision in Agua Caliente Band v. Coachella Valley Water District (9th Cir. 2017) 849 F.3d 1262, the Ninth Circuit affirmed the District Court’s holding based on its interpretation of the Winters doctrine (Winters v. United States (1908) 207 U.S. 564), and concluded that by reserving lands for the Tribe, the federal government impliedly also reserved water rights for the Tribe to sustain its use and enjoyment of the reserved lands. Thus, for the first time, the Ninth Circuit extended the Winters doctrine to apply to groundwater. But the panel also noted that exactly what quantity and quality of water the Tribe's right entailed would have to be addressed in the subsequent phases of the suit.

The Supreme Court declined to review that decision.

Subsequent District Court Ruling

Upon remand, all parties filed separate motions for summary judgment as to Phase II issues: (1) whether the Tribe beneficially owns pore space underlying the reservation; (2) whether the Tribe’s groundwater rights include a water quality component; and (3) the legal standard for quantifying the Tribe’s reserved water rights. On April 19, 2019, the District Court issued its decision denying the Tribe’s motion for summary judgment, granting-in-part the defendant water agencies’ motions for summary judgment as to the Tribe’s quantification and quality claims, and deferring judgment as to all other issues raised in the motions.

In its decision the District Court first addressed quantification, and found that the Tribe lacks standing to seek quantification of its federal reserved right to groundwater, noting that although non-use does not destroy the Tribe’s federal reserved right, it does impact whether the Tribe has standing to quantify the right. The District Court then concluded that the Tribe presented no evidence of intent to pump groundwater, and that the overdraft condition alone is not sufficient evidence to satisfy the Tribe’s burden to provide evidence of injury to itself. In other words, the Tribe failed to present evidence of an actual or imminent injury to its federal reserved right, and the mere existence of overdraft, without evidence of intent to pump, is not sufficient to satisfy the injury requirement.

Next the District Court tackled the issue of whether there is a water quality component of the reserved right. For purposes of standing, the District Court reasoned that the Tribe must provide evidence that recharging the aquifer with Colorado River water actually or imminently impairs the Tribe’s ability to use water of sufficient quality to fulfill the purposes of the reservation. The District Court, however, concluded that the evidence does not indicate the Tribe cannot use the water to fulfill the purposes of the reservation. According to the District Court, while the Tribe presented evidence that the recharge of Colorado River water will result in higher TDS levels in the groundwater, that injury to water, alone, is not sufficient. Rather, the Tribe needed to demonstrate that changes to the TDS level in the aquifer would preclude the Tribe, currently or imminently, from being able to use its reserved water for any purpose.

Finally, the District Court addressed the Tribe’s claim to ownership of pore space underlying the reservation. Pore space, for purposes of the Tribe’s claim, is defined as the void or open subterranean spaces that are not filled by solid material, the empty space between rocks, sand, and other solid soil where water can be stored. The District Court found “a concrete conflict” on the ownership issue and concluded that the Tribe does have standing to seek a declaration that it has ownership of sufficient pore space to store its federally reserved water.

Similar to its findings on the other issues, however, the District Court also found that the Tribe did not provide evidence to support the existence of an actual or imminent threat to its ability to store water of any quantity necessary to fulfill the purposes of the reservation. Thus, the District Court concluded that while the Tribe has standing to seek a declaration concerning pore space, it does not have standing to seek injunctive relief concerning that pore space.


Notwithstanding the likelihood of an appeal to the Ninth Circuit, the District Court’s latest decision greatly limits its 2015 landmark decision establishing that the Tribe has a federal reserved right to groundwater. In short, the District Court found that although the Tribe has a federal reserved right to groundwater, it does not presently pump or have an intent to pump that groundwater, and thus lacks standing to seek quantification and a right to groundwater of certain quality. As noted by the District Court in its decision “[T]he fact that the Tribe does not lose its reserved right by non-use does not mean the Tribe automatically has standing to adjudicate the scope of that right.”

One key issue remains in the litigation for the District Court’s determination: whether the Tribe has an ownership stake in the aquifer's empty storage space.