Arizona water managers have been leading a series of biweekly meetings since July to work out details of the proposed drought-contingency plan.
The chances of a shortfall in Lake Mead, the Colorado River’s biggest reservoir, are now 57 percent, up from the 52 percent projected in May.
In western Colorado, volunteers say they’re preparing to bring up to 5,000 gallons of water per day to a herd of 750 desperate horses.
Arizona is renewing a focus on a drought contingency plan for the shrinking supply of Colorado River water, and other Western states are paying close attention.
Projections show there's a chance that Lake Mead will fall low enough in 2020 to trigger cutbacks under agreements governing the system.
The Colorado River is expected to only carry 43 percent of the average amount of water into Lake Powell this year.
John Fleck, director of the University of New Mexico Water Resources Program, says there are signs that years of work could be at risk.
The normal staid diplomacy of Colorado River managers was upended in a spat between Denver Water and the Central Arizona Project.