A top federal official has resumed pressure on states in the Southwest to wrap up long-delayed emergency plans for potential shortages on the Colorado River.
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.