Jan. 7 (Bloomberg) -- Arizona rivers are flowing for the first time in seven years after winter storms provided some relief to the drought-stricken U.S. Southwest.

The Salt River Project, which operates dams and power plants in the Phoenix region, was able to release water in the river that runs through Phoenix for the first time since 1998, spokesman Scott Harelson said in a telephone interview.

``We're experiencing our first above-average precipitation since the winter of 1997-1998,'' Harelson said. ``Some of our reservoirs are running out of capacity and we have been spilling water in the normally dry river bed.''

The drought that has plagued Arizona, Nevada and other states in the Southwest, has diminished the flow into the Colorado River, which supplies water to fast-growing communities in Southern California as well as to Las Vegas and Phoenix. Hydropower production along the Colorado River has also been reduced because of the drought.

The storms of the last two weeks have brought about five times the normal amount of rainfall to parts of western Arizona, said Michael Hayes, a climate-impact specialist at the National Drought Mitigation Center at the University of Nebraska. Rainfall in eastern Arizona is still below average and the storms may have little long-term impact on the drought, he said.

``Of course, it can't do anything but help the situation we've had in the Southwest for the past five to seven years,'' Hayes said in a telephone interview. ``But we will have to see whether Lake Mead and Lake Powell, the biggest reservoirs along the Colorado, are going to get some replenishments from the storms.''

Snow, Rain, Mudslides

A low-pressure system off the coast of California sent storms through the state over the past week, bringing snow and rain and closing roads, causing mudslides and knocking out power.

The Colorado River reservoirs get most their water from snowfall further to the north, in Utah and Colorado, while most of the rain has been falling to the west, in California, and in Arizona, Hayes said. Climate experts have no sure ways of knowing how many years of above-average rain it might take for the region to completely recover from the years of drought.

``When the Missouri basin fell to record-low levels in the late 80s and early 90s, people said it might take as much as 10 years to recover,'' Hayes said. ``It turned out that it was replenished in one very rainy year.''

In Arizona, some of the biggest reservoirs are still below capacity. The Theodore Roosevelt Lake, the biggest in the Salt Water Project's system, was still at only 41 percent of capacity after the storms, Harelson said. That was up from as low as 33 percent of capacity two weeks ago, he said.

To contact the reporter on this story: Edvard Pettersson in Los Angeles at epettersson@bloomberg.net.

Last Updated: January 7, 2005 09:06 EST