The Central Arizona Projectโs governing board took the first steps Thursday toward approving Arizonaโs share of a plan to save a half-million acre-feet a year of Colorado River water in order to prop up ailing Lake Mead.
The plan, adopted unanimously by the board, calls for Arizona users of the river water โ mostly those on CAP supplies โ to shoulder more than 40% of that total, or 223,000 acre-feet in 2022. The cuts are all supposed to be voluntary and temporary, and to be compensated by either state or federal money, totalling $100 million a year for the entire conservation program.
Arizona tribes are expected to save the largest share, of well over 100,000 acre feet. Another 50,000 to 60,000 acre feet of savings, enough to serve Tucson for at least half a year, could come from tribal, agricultural or urban users.
Another 215,000 acre-feet would come from California water users. The U.S. Bureau of Reclamation would supply 62,000 acre-feet in cuts.
The plan is seen as an emergency measure for 2022 to prop up the lake until longer-term water savings can be realized. Specifics of cuts for 2023 remain undecided.
Out of the $100 million annual tab, Arizona, Nevada and California would supply $50 million total and the federal government would supply $50 million. Over the two-year period, the Arizona Department of Water Resources would supply $60 million, CAP would provide $20 million, Southern California's Metropolitan Water District would provide $20 million and the feds would provide $100 million.
Together, the 500,000 acre-feet is almost as much as the 533,000 acre-feet that Arizona and Nevada were already required to save next year in Colorado River deliveries under the terms of the 2019 Drought Contingency Plan.
CAP staffers and board members made it clear at Thursdayโs meeting that this plan is only the start of the need to save additional water beyond whatโs already set to be conserved, under the 2019 drought plan, through 2026.
The plan CAP approved โ and that will ultimately be adopted by all three states in the riverโs Lower Basin โ calls for 500,000 acre-feet to be saved in both 2022 and 2023, with a clear intent to continue the annual savings for the next five years. Those states are Arizona, California and Nevada.
The plan was worked out in private negotiations this year among the states. Details are supposed to be announced at the annual Colorado River Water Users Association conference in Las Vegas Dec. 14-16.
The goal is to keep Lake Mead from falling below 1,020 feet over the next few years. That level would most likely require much more severe and potentially crippling cuts in river water deliveries to the Lower Basin states.
Lake Mead is forecast to be at around 1,067 feet by the end of 2021.
Computer model results disclosed by CAP staff at Thursdayโs meeting show the 500,000 acre-feet of savings would dramatically decrease the risk of Mead falling below 1,020. Even if river flows are as low as 10% of what could theoretically come down the Colorado, these savings would keep Mead at 1,020 or higher through 2026.
The modeling was conducted by the CAP and the Southern Nevada Water Authority and is now being confirmed by the U.S. Bureau of Reclamation, CAP says.
By then, the three states are supposed to have approved a much longer-term plan to balance water demands and supplies on the river, which is over-allocated and also reeling under the impacts of climate change and long-term drought.
Left unsettled at this point is precisely which Arizona water users would shoulder the additional cuts in 2022 and 2023.
The plan calls for the following division of cuts:
Only 40,000 acre-feet of the savings would come from CAP water users along the river, The remaining 193,000 would come from users lying within CAP's service area in Pima, Maricopa and Pinal counties.
The CAP board approved sending โletters of intentโ to negotiate conservation agreements with the Parker-based Colorado River Indian Tribes and three non-Indian irrigation districts operating along the river. They include the Wellton-Mohawk and Yuma Mesa districts in the Yuma area in Southwest Arizona and the Mohave Valley Irrigation District in Mohave County in Northwest Arizona.
The remaining savings would come from CAP water users. They would be led by the Gila River Indian Community in Central Arizona, at more than 100,000 acre feet. That includes 78,000 acre feet whose savings would be compensated for by the Bureau of Reclamation.
Another category of potential conservation, of 50,000 to 60,000 acre feet, could come from any CAP user, either municipal, industrial or agricultural. So far, the response from those users has been โnot as robust as we would like,โ CAP General Manager Ted Cooke told the board. Tucson and Phoenix both receive CAP deliveries.
He cited higher costs the cities are already facing, and the prospect that users who take less water will have to pay more per acre foot for what they will continue to get, as some of the reasons. Also, the municipal and industrial users got word of the need for these savings late in the year, he said.
Much lesser amounts would come from the Salt River Project, a water and electrical utility serving much of the Phoenix area, and from savings created by leaving additional water in Lake Pleasant northwest of Phoenix.
