Spring runoff predicted to be higher than normal

PHOENIX - The Arizona Basin Outlook Report released this week by USDA’s Natural Resources Conservation Service (NRCS) shows the state snowpack to be well above average levels. The federal agency monitors snow conditions in Arizona’s mountain watersheds each winter to estimate the amount of surface water that will be available for spring and summer uses.

“The storms that moved through the state during the last week of January produced abundant snow and rain throughout the mountains of the state,” said Dino DeSimone, State water supply specialist with the NRCS in Phoenix, Arizona. “In fact, many of our snow measurement sites reported more than double the normal amount of precipitation for the month.”

As a result of all this moisture, NRCS is predicting that Arizona’s major rivers will produce flows up to 272 percent of normal amounts during the spring runoff period.

Among the findings in the Basin Outlook Report, the state-wide snowpack is well above normal at 159 percent of the 30-year average. The snowpack in the Salt River Basin was measured at 116 percent of average; the Verde River Basin at 166 percent; the San Francisco-Upper Gila Basin at 88 percent; and the Little Colorado River Basin at 152 percent of average snowpack.

“The recent storms have saturated the soils in the mountains,” DeSimone continued. “This means that most of the water stored in the snowpack will eventually melt and produce higher than normal runoff in the state’s streams and rivers. This runoff will help replenish our major reservoirs, such as Roosevelt Lake on the Salt River.”

NRCS hydrologist runoff predictions are conducted bi-monthly based on the current snowpack accumulations. As the season progresses, forecasts become more accurate, primarily because a greater portion of the future weather conditions become known.

The NRCS Arizona Basin Outlook Report and other related reports are available at http://www.az.nrcs.usda.gov/snow.   back...