After the Supreme Court declined to hear an appeal, the Ninth Circuit will decide a Southern California tribe’s share of Coachella Valley Aquifer – a decision that’s being watched closely by tribes across the West.

ON MONDAY, NOVEMBER 27, the United States Supreme Court let stand a California federal appellate court decision that could chart a new course for Native American tribal groundwater rights. In the case, Agua Caliente Band v. Coachella Valley Water District, a three-judge panel of the U.S. Court of Appeals for the Ninth Circuit had ruled on March 7 that the tribe’s water rights include an aquifer that lies beneath the Palm Springs-based tribe’s 31,500-acre reservation.

“The United States impliedly reserved appurtenant water sources, including groundwater, when it created the Tribe’s reservation in California’s arid Coachella Valley,” the judges ruled. The court’s decision is based on the Winters Doctrine, which springs from a 1908 Supreme Court decision that reserves the federal government’s right to reserve sufficient water for Indian reservations’ needs.

This decision is one part of a multifaceted case, but it is being closely watched across the West as it now affirms that tribes have a federally reserved right to groundwater.

The Agua Caliente case was the culmination of a struggle over nearly two-decades by the tribe of more than 400 members to ensure that their sole water source remains as clean as it was when Europeans first came to the arid region on the borders of the Mojave and Sonoran deserts. In 2013, the tribe filed a suit against the Coachella Valley Water District (CVWD) and the Desert Water Agency, which together manage water resources for the region, to gain ownership and control of a portion of the aquifer.

The Agua Caliente tribe, one of a number of Cahuilla tribes in Southern California, has long been worried about dropping levels in the 65-mile-long aquifer – some 55ft over the past 40 years – a concern that the local water districts share. However, the tribe has also opposed the two local agencies’ solution to overpumping by percolating untreated Colorado River water into the aquifer.

The water districts maintain that the river water meets federal standards. However, Agua Caliente disagrees and other water agencies are also concerned with water quality in the Colorado River. Some of the region’s biggest water agencies – the Central Arizona Project (CAP), the Southern Nevada Water Authority and the Metropolitan Water District of Southern California – formed the Lower Colorado River Water Quality Partnership to address issues that impact Colorado River quality, including dissolved salts, selenium, phosphorus, nitrate, pathogens, pharmaceutical and personal care products, perchlorate, chromium 6 and uranium. In a white paperCAPofficials determined that these contaminants could pose an “immediate or long-term threat to the river’s water quality.”

But CVWD board president, John Powell, Jr., said, “We believe that the claim about Colorado River being polluted is a false claim. Actually, bacteria is our main concern. But we have a tremendous quantity of sand media in our percolation ponds, which is filtering the bacteria out.”

The tribe was happy to hear Monday’s Supreme Court decision. “Because of the Supreme Court’s decision, the favorable rulings from the U.S. District Court and the 9th Circuit Court of Appeals recognizing and protecting the Reservation’s federal water right are now settled law,” Agua Caliente chairman Jeff Grubbe said in a statement.

The water districts were less pleased with the Supreme Court’s decision. “We are disappointed in the decision because we believe the water in this valley is a shared resources [sic] that belongs to everyone,” Powell said in a statement. “The Tribe has always had access to as much water as they requested, but now they have secured a water right that is superior to every other resident and business in the Coachella Valley.”

The districts have long argued that Agua Caliente isn’t as worried about water quality as it is about commercial uses for the water.

“The case is going to be very important for any state within the Ninth Circuit,” said Judith Dworkin, an Indian law and tribal relations attorney for Phoenix-based law firm Sacks Tierney, who has worked on tribal water rights settlement and litigation. She was not involved in the Agua Caliente case.

However, not all states will be affected by the decision. “In Arizona, the decision is not nearly as important as in other jurisdictions within the Ninth Circuit, as the Arizona Supreme Court has already determined that a tribe may have a federal reserved right to groundwater if surface waters are inadequate to accomplish the reservation’s purposes,” Dworkin said. The court also has jurisdiction in Alaska, Arizona, California, Hawaii, Idaho, Montana, Nevada, Oregon and Washington.

Despite this decision, the case is also not completely resolved. The Ninth Circuit Court will hold a trial to determine how much of the aquifer belongs to Agua Caliente.

“The tribe, the United States and the water agencies are in the midst of briefing for the court on what are called the Phase 2 Legal Issues – the correct standard or methodology for quantifying the tribe’s share, whether the federal reserved or Winters water right carries with it a right to water of a certain quality and whether the tribe owns the groundwater storage space, or pore space, under its reservation,” said Kate Anderson, director of public relations for Agua Caliente.

Tribes, states and other entities who joined in the suit on both sides of the issue are watching to see what happens next.

“From a tribe’s perspective, I think it is an important decision that allows tribes to explore the range of water sources available to it in developing a long-term plan,” said Dworkin. “From the non-Indian parties’ perspective it may require those with state water rights to establish working relationships with tribes to develop aquifer management programs.”

Dworkin says that the Agua Caliente decision should provide an opportunity for tribes in California and elsewhere in the Ninth Circuit to meet with non-Indian parties and the federal government to negotiate settlements of water rights rather than rely on litigation to resolve the issues.

“Parties can have greater control of the outcome in settlement negotiations if all the parties to the adjudication are reasonable and are prepared to negotiate in good faith,” she said. “In those areas where there may be competing demands for groundwater, the Agua Caliente decision should motivate settlement negotiations that include, in addition to a determination of a right to groundwater, administration of the resource, rather than leaving the parties with the uncertain outcome of a court proceeding.”

This article originally appeared on Water Deeply. You can find the original here.  For important news about water issues and the American West, you can sign up to the Water Deeply email list.

Teaser photo credit: By Mfield, Matthew Field, http://www.photography.mattfield.com – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4951866