Legislation that aims to bring water rights peace to the region was introduced late last week by U.S. Rep. Mary Bono Mack.

Titled "The Pechanga Band of Luiseno Mission Indians Water Rights Settlement Act" (H.R. 4285), the bill details how the U.S. government will pay millions of dollars to ensure the reliability of the Pechanga's water supply and it settles decades-old competing water claims involving the tribe, Rancho California Water District and Eastern Municipal Water District.

Putting the importance of the legislation introduced by the Palm Springs Republican in context, tribal officials said Monday that it is an "incredibly important" moment for the tribe.

"Pechanga has fought for recognition and protection of its federally reserved water rights for several decades," Tribe Chairman Mark Macarro stated in an e-mail to The Californian. "This agreement and legislation will resolve this struggle by providing the Tribe with a certain and stable supply of water for future generations."

Under the 1908 Indian Water Rights Settlement, the federal government pledged to provide sufficient water resources to tribes forced to live on reservations.

In recent years, as Southern California has found the reliability of its water deliveries compromised by legal battles involving the Sacramento-San Joaquin Delta, the tribe stepped up negotiations with Rancho Water and the Eastern Municipal Water District to hash out claims to groundwater in the Santa Margarita River basin.

Both the tribe and the district draw water from aquifers in the basin ---- which stretches 750 square miles from Southwest County to northern San Diego County.

Under the draft version of a framework that was negotiated late last year ---- a document that was used as the outline for the legislation ---- federal funding will be used to make sure Pechanga has physical access to water supplies equal to the amount they were awarded in a mid-1960s federal court order called the "Fallbrook Decree," which amounts to about 5,000 acre-feet of water a year.

An acre-foot of water equals 326,000 gallons, about the amount two families use in a typical year.

In addition, Rancho will end up providing more water from the Wolf Valley Basin and other sources, including water from the much larger Metropolitan Water District.

In early 2007, the tribe and the district each agreed to draw up to 489 million gallons per year from Wolf Valley's aquifer. District officials said they expect this 2007 agreement will be finalized and folded into the new agreement.

In exchange for that increased supply, the Pechanga have agreed to provide to Rancho Water a portion of federal funds the tribe will receive as part of the settlement.

That money ---- about $50 million, according to the bill ---- will be used by the district to build a new desalination plant to treat wastewater, water district officials said.

The new supply of treated wastewater would be sold to farms, freeing up enough water for 70,000 homes, said Rancho Water spokeswoman Meggan Reed.

Another part of the negotiations involves the tribe and the district agreeing on what's called a "dry year supply agreement." This agreement, when finalized, would provide the district with access to additional water resources during periods of drought.

Call staff writer Aaron Claverie at 951-676-4315, ext. 2624.