A tentative water rights agreement that was reached between the Pechanga Indian tribe and the Rancho California Water District a year ago would be cemented under legislation recently introduced by Congresswoman Mary Bono Mack.

The legislation was praised by the two groups, but formalizing the tentative settlement would not end one of California’s longest-running water-rights lawsuits. It would merely remove two key players and possibly shift a legal fight in the vast basin that is drained by the Santa Margarita River.

"Rancho California Water District appreciates the efforts of Representative Bono Mack in sponsoring this legislation," Matt Stone, agency general manager, said in a news release. "We look forward to working with all the settlement parties for passage of the bill."

Pechanga officials were equally upbeat.

"This settlement provides a large measure of certainty to Pechanga’s future in terms of water supply," Tribal Chairman Mark Macarro said in a written statement.  "Clearly, the hard work and time invested by representatives of these water agencies and the tribe has resulted in a mutually advantageous agreement."

The legislation, introduced Dec. 11, is the latest movement in the steadily-changing landscape of agreements surrounding a vast aquifer below much of southern Temecula. That aquifer and others – as well access to the river – have been the subject of legislation and litigation among numerous agencies and tribes for more than 80 years.

The serpentine Santa Margarita River forms at the junction of Murrieta and Temecula creeks at Temecula’s southwest corner. It flows 27 miles to the ocean through pristine, largely undeveloped canyons and rolling tracts that include an ecological reserve, Fallbrook Public Utility District land and Camp Pendleton.

Frequently described as Southern California’s last free-flowing river, the Santa Margarita drains a 749-square-mile watershed that takes in the Lake Skinner and Anza areas. Flows of the river and its tributaries, as well as the underground basins below them, have been critical supplies since Indian bands first ventured into the region thousands of years ago.

The thaw over the Wolf Basin, which the tribe and district can both tap, began to take shape in August 2006 when the two groups reached a sharing agreement.

The aquifer’s output had become strained in recent years because of drought conditions and increased demand due to the area’s rapid growth. Both entities have extracted supplies from the basin, but fears of drawing it down too low had prompted Rancho to discontinue pumping at times.

In turn, the Pechanga tribe needed to improve the reliability of its supplies. Expansions of its hotel and casino – as well as opening a golf course – depended on the tribe’s ability to guarantee future flows of water for drinking and irrigation.

The aquifer-sharing agreement established Advertisement

PHR Management the basin’s "safe yield" and guaranteed each side certain annual amounts. It also gave the tribe access to reclaimed water for its golf course and the ability to tap imported supplies if needed.

The relationship between the district and tribe was solidified about a year ago when a draft accord surfaced after behind-the-scenes meetings.

The Bono Mack legislation would ratify that agreement and resolve the portion of the water rights lawsuit that pertains to Rancho and Pechanga. She said it would "bring an end to decades of litigation and uncertainty on water rights issues" as the state grapples with supply issues elsewhere.

"This bill is the direct result of many years of hard work and time invested by the tribe, our local water districts, and local leaders to reach an agreement on critical water resources," Bono Mack said in a news release. "I praise their collaborative efforts and am proud to offer this legislation that will bring needed relief to the tribe and local residents."

In addition to winning congressional approval, the agreement would need to be approved by a federal district court judge before it could take effect.

As part of the settlement, Pechanga could receive federal funds that would satisfy claims the tribe previously made against the government. Pechanga would provide some of those federal funds to help Rancho upgrade its water delivery system, Macarro said.

Those funds could help offset the estimated $103 million cost to build a proposed desalination plant for the area. Fears of rising salt levels in basin supplies have escalated due to the increased use of reclaimed water on golf courses and other landscaped areas. A desalination plant is part of Rancho’s long-term service plan for the area.

Bono Mack’s legislation would not affect any other groups or agencies that have rights to tap water in the Santa Margarita Basin.

In December 2006 the Cahuilla tribe, which operates a small casino in the rural Anza area, asked a federal judge to reopen the historic lawsuit.

The tribe said federal case law had recognized its reservation’s water rights in 1908 and that federal attorneys had represented Cahuilla rights at earlier Santa Margarita water rights proceedings.

Those rulings gave the tribe rights to waters flowing through and beneath its nearly 13,000 acres of reservation land, according to Cahuilla court filings. The tribe contends that earlier court rulings and settlements stopped short of quantifying Cahuilla’s water rights and rapid development over the past hundred years has created "an enormous burden on water resources for all residents."

The potential effects that request could have on water supply issues in the Anza area and beyond is uncertain because that tribe’s claims are still pending in federal court.