Supply not meeting demand
Water use on Colorado prompts drought fears
As over-demand and under-supply continue to pull down water levels in Lake Mead, water managers for the three lower Colorado River Basin states failed to reach an agreement last week on protecting water supplies in Lake Mead.
During its annual meeting in Las Vegas, the Colorado River Water Users Association — Arizona, New Mexico and California — tried to adopt a “Drought Contingency Plan” aimed at reducing water use from Lake Mead but failed to finalize the plan.
The reservoir behind Hoover Dam has not reached full capacity since 1983 and is now at its lowest level (1,112 feet above sea level as of Tuesday) since it was first filled in the mid-1930s.
Should the elevation of Lake Mead drop below 1,020 feet, power generation and water deliveries to nearby cities become threatened.
Although a major drought plan, in the works for three and a half years, wasn’t adopted and won’t be before next month’s change in administration, a temporary plan, the “Arizona plan,” may bridge the over-allocation problems of the Colorado River water system, water officials said.
Commissioner of Reclamation Estevan López said the key feature of the deal is an agreement to “protect 1,020”, that being the level where there is less than a year’s water left in the reservoir.
At current rates of use, it would take extraordinary steps by the Colorado River Lower Basin water users to prevent Lake Mead from dropping below 1,020 feet.
Had the Drought Contingency Plan been adopted, Arizona, California, and Nevada voluntarily would pursue further cuts in their use of Colorado River water.
That unused water would be banked in Lake Mead in an effort to keep that reservoir from dropping below critical levels.
The plan would have been the third major water-sharing agreement among the states and the federal government, including the 2007 shortage sharing guidelines adopted by the seven Colorado River basin states.
As author John Fleck reported on his website (inkstain.net) earlier this month, such deals “have repeatedly sidestepped the risk of litigation over … who is entitled to how much of the river’s increasingly scarce water.”
The demand for Colorado River water exceeds the supply. The Upper Basin states are legally required each year to send 8.23 million acre-feet — including Mexico’s share — to the Lower Basin.
But that’s well short of the 9 million acre feet taken each year by the Lower Basin, which is one reason why Lake Mead is shrinking.
According to notes from the Central Arizona Project, which pumps Colorado River water uphill from Lake Havasu to the Tucson-Phoenix area, Lake Mead each year loses about 1.2 million acre feet.
Arizona is the first in line for cuts should the drought continue.
Jim Pokrandt of the Colorado River Water Conservation District ran down the list of hurdles faced by the Lower Basin when developing some sort of equitable drought-sharing plan.
These include California’s Salton Sea, created by a 1906 flood when the Colorado River overran its banks, which remains a “festering problem,” Pokrandt said.
As that inland lake shrinks due to water transfers, wildlife habitat is lost and the playa’s salt and heavy-metal tainted soils are exposed to the wind, authorities fear the result will be massive air pollution.
Fleck, working with CAP numbers, said only through “periodic infusions — extra water (from the Upper Basin) during unusually wet years —can the Lower Basin make ends meet.”
So why is this Lower Basin agreement important to Colorado and the Upper Basin states? It hinges on the role of Lake Powell, which is used to stabilize levels in Lake Mead.
“It’s all linked,” Pokrandt said. “What the Lower Basin does impacts the water level at Lake Powell. Until the Lower Basin solves anything, the efforts of the Upper Basin (to keep water in Lake Powell) are almost moot.”
Failing to come to an agreement this year brings another worry.
As noted by the Daily Star’s Tony Davis, should an agreement be reached, no one knows if the decision will be accepted by the incoming Trump administration.