But neighboring states are addressing the problem at the state level and finding ways to mitigate present and future problems for the advantage of both surface and ground water users.

That was the emphasis Monday at the summer conference of the Groundwater Management Districts Association at the Stanley Hotel in Estes Park. About 125 water users from Colorado as well as Mississippi, Texas, New Mexico, Nebraska, Kansas, Wyoming and Idaho registered for the three-day conference, which concludes today.

Monday's sessions concentrated on irrigation well shutdowns or curtailment of irrigation wells in Nebraska, New Mexico, Wyoming, Idaho and Colorado, which also included an overview of problems in other western states by Melinda Kassen, Western Water Project director for Trout Unlimited.

Kassen said ground water in the 1950s was seen as a new source of water, but only recently have Western states come to the realization that ground and surface water are connected and that pumping of wells has an effect on river flows. In Colorado, only 22 percent of the state's population depends on ground water for domestic needs, but in New Mexico, 90 percent of the population depends on that source while 96 percent of Idaho's residents use ground water.

That, combined with a drought that signaled the start of the 21st century, has led to the shutdown of wells, such as those along the South Platte River last year.

"Colorado's regulatory system should have prevented that catastrophe, but it did not," Kassen said. "That was an extraordinary wake-up call."

The over-use of ground water supplies is creating problems for many states west of the Mississippi River. Kassen said one river in Arizona has lost all but two of 13 native fish species, while in northern Montana, a developer was denied a permit for a golf resort along the Gallatin River until it could come up with a water replacement plan for the wells it wanted. That led to the Montana legislature passing a new ground water measure this year.

In Nebraska, where the number of high capacity wells increased from about 6,000 in 1975, to more than 103,000 by this year, many areas are facing moratoriums, said Jim Goecke with the University of Nebraska.

"Nobody wants moratoriums," he said, but as water levels continue to decline in major aquifers, that may happen.

In southern New Mexico, along the Rio Grande, the state legislature is helping to developing surface water treatment plants for use by municipalities and industry to ensure the continued use of wells in a highly productive agricultural area, said Gary Esslinger, manager of the Elephant Butte Irrigation District of Las Cruces.

While no wells have been shut down in Nebraska, Goecke summed the problem.