In all, 26 states are in the throes of a severe drought, according to the most recent survey by the National Drought Mitigation Center at the University of Nebraska.
An exceptional drought, the most severe ranking, was found in Colorado, Wyoming, Utah, Arizona and New Mexico, center climatologist Mark Svoboda said. Exceptional droughts occur once or twice in a century.
Denver's water resources, serving 1.1 million customers, reached an all-time low this month, registering 63 percent full compared to 80 percent during the same period a year ago. Aurora's reservoirs are at 48 percent of normal compared with 81 percent this time last year.
Complicating the issue are the sediment and ash covering slopes stripped bare by a 137,000-acre wildfire southwest of Denver earlier this year. Officials fear the debris will wash into Cheesman Reservoir, key to the city's water supply.
"This is the worst drought on record and the biggest wildfire in the history of the state, so it's pretty bad," Denver Water Department spokeswoman Jane Earle said.
To dilute the sediment, Denver water managers plan to divert water from two mountain reservoirs into the deeper Cheesman Reservoir.
Summer monsoons could provide short-term relief but likely will not have a large effect, climatologists say. Water managers fear the drought may extend into next year and beyond.
Hoping to bolster the winter snowpack, which provides about 80 percent of the area's surface water, the Denver Water Department plans to spend $700,000 next winter for cloud seeding near the Continental Divide.
In the meantime, cities are working to get people to conserve water.
Colorado Municipal League spokesman Mike Bratten said at least a dozen cities have mandatory restrictions while others have voluntary restrictions. Denver, Boulder and Aurora have water cops; so do Las Vegas and Albuquerque, N.M., which also has a "wasted water hot line" where violators can be reported.
Newspaper editorial pages have been filled with finger pointing at suburban homeowners' associations that require green lawns.