Washington, Feb 3 (IANS): Seven states in the parched southwest US are waiting for President Joe Biden's administration to resolve their dilemma pm how to fairly distribute waters from the waning Colorado River.

Six of the seven states -- Arizona, Colorado, Nevada, New Mexico, Utah and Wyoming -- reached an agreement this week, but the seventh and most significant, California, told the others to "get lost", Xinhua news agency quoted a Politico news report as saying on Thursday.

The Colorado River, which supplies water to cities, farming areas and tribal nations from the Rocky Mountains to the U.S.-Mexico border, has been pushed to a breaking point by chronic overuse, drought and the effects of global warming.

Due to an historic 1,200-year drought that dropped the country's two biggest reservoirs on the river, Lake Mead and Lake Powell, to record low levels, federal officials required each of the seven states that rely on the river to come up with alternatives for making water cutbacks by the end of January.

Tuesday was the deadline imposed by the Interior Department for plans on how to voluntarily reduce water usage by 2-4 million acre-feet, or up to one-third of the river's annual average flow.

The six Colorado River basin states "sketched out a joint proposal" on that day on how to meet the federal government's demand to make unprecedented cuts to water usage.

Under the proposal, a large portion of the proposed water cuts would be made by accounting for evaporation and other water losses along the lower portion of the river, meaning a large reduction for California.

The Golden State, the most populous state of the country, refused to accept it.

"California is insisting on its legal claims under a compact dating back to 1922 as the river faces unprecedented strain because of climate change and population growth in the Southwest," Politico said.

"The fact that six of them came together and put forth this proposal, that stands out," National Public Radio (NPR) said,

"They're trying to meet the needs of cities and farms from Wyoming to Mexico, and that is not an easy task."

The southern states most affected, California and Arizona, are pitted on two sides of the debate, with Arizona wanting water for housing communities and the ensuing tax benefits, while California argued its allocation of the river water helped feed millions from its verdant farm lands.

California is also the river's largest water user, the Washington Post said, with the impasse suggesting that "wrangling over how to conserve the dwindling water supply, that serves 40 million people, will continue in coming months".

The standoff thrusts the Biden administration into the position of deciding how to resolve competing claims on water shared among 40 million people.

As the stalemate fell into the federal government's lap, California's six opposing states "urged President Joe Biden to support their proposal" in a letter on Wednesday, Politico said.

"But California Natural Resources Secretary Wade Crowfoot, as well as the state's two senators have criticized the six-state plan," Politico reported, "saying it would disproportionately burden California cities and farmers."

Moreover, recently, a new player entered the imbroglio, further complicating the issue and seemingly ignored in the conflagration between America's Southwest states.

Over the years, the country of Mexico has grudgingly accepted cutting its allocation of the river.

When the Colorado River reaches the US-Mexico border, it pushes up against Morelos Dam, nearly all the remaining water is shunted aside into an immense canal and flows toward the farmlands and cities of Baja California, but south of the dam, the last of the river disappears in the desert.

In 2022, Mexico lost 5 per cent of its water from the Colorado River, but this year, it will lose 7 per cent.

Mexico is entitled to receive 1.5 million acre-feet of water per year under a 1944 treaty, but in recent agreements with the US, Mexico has also agreed to take part in reductions when there is a shortage, according to the report.

More than a century ago, the river's delta spread across 1.9 million acres of wetlands and forests, and was described by conservationist Aldo Leopold in 1922 as "a hundred green lagoons" and waters "of a deep emerald hue".

The area, described by Leopold as "an oasis that teemed with fish, birds, beavers, deer and jaguars", as a pristine environment, however, was lost forever when the river was dammed.