The current drought, considered the worst in 500 years, just may be the beginning of a drier West, experts say.

Researchers at the U.S. Geological Survey, who have produced a fact sheet on climatic conditions and Colorado River flow, say predicted inflows of Colorado River water into Lake Powell indicate the drought is ongoing. However, they also point out their ability to predict water resources in the Colorado River Basin is poor.

Dan McCool, director of the American West Center at the University of Utah and an expert on Western water issues, said there is no shortage of water in Utah and the West for human use inside residences, just a distribution problem resulting from outdated water policies and laws. And, he says, scarce water should not be used to grow crops in the West.

Scientists at the U.S. Geological Survey say the drought, which started in 1996, is having effects on the Colorado River Basin that are worse than during the Dust Bowl years of the Depression. Mike Hayes, climate specialist at the Drought Mitigation Center, Lincoln, Neb., said the 1930s Dust Bowl was not as bad in the West as it was in the Plains states.

The current drought has produced the lowest flow of the Colorado on record, with an annual average flow of 5.4 million acre-feet at Lees Ferry, Ariz., during 2001-03. By comparison, during the Dust Bowl years, 1930-37, the annual flow averaged about 10.2 million acre feet, the report by four USGS researchers said.

The current drought, called the early 21st century drought by the USGS, has its origins in several global-scale atmospheric and oceanic processes that reduce delivery of moisture to the Colorado River Basin. The indices used to measure weather conditions are so complex scientists are reluctant to predict when a drought will end or begin.

Tree-ring measurements are used by scientists to estimate Colorado River flows and moisture conditions before record-keeping began in 1895. Using that method, the lowest five-year average of water flow was 8.84 million acre-feet in the years 1590-94. From 1999 through last year, water flow was 7.11 million acre-feet, the report said.

One of the most important conclusions from tree-ring measuring is that the period from 1906 through 1930, which was partially used to determine flow allocations under the Colorado River Compact, was likely the highest period of runoff in 450 years, the report said.