The Natural Resources Conservation Service (NRCS) and cooperating partners are forecasting normal to below normal runoff in Arizona’s major rivers and streams for the remainder of the forecast period through May based on recent snowpack measurements.
March runoff was 125 percent of normal on the Salt River and 219 percent of normal on the Verde River. The Salt and Verde River reservoirs are essentially full at 98 percent of capacity.
Statewide, the April 1 snowpack measured 87 percent of the 30-year average. The snowpack is rapidly melting and is virtually gone below the 7,500 feet elevation. Monitoring stations showed very little precipitation in March, ranging from 7 percent to 11 percent of average.
Dino DeSimone, NRCS water resources specialist, said that as a result of receiving essentially no precipitation during the past month, the forecast calls for normal to below normal streamflows in all basins for the remainder of the spring snowmelt season.
“This winter started out with some big storms producing well above average snowpacks, but due to an extremely dry March, we’re ending the season with low numbers for streamflow. Overall, however, this has been a very good winter in terms of total precipitation and runoff, resulting in filling of the reservoirs on the Salt River Project system,” said DeSimone.
NRCS takes snow measurements throughout the winter to forecast and track the state’s surface water supplies for the coming year. As a result of these snow measurements, an Arizona Basin Outlook Report is developed and issued every two weeks beginning Jan. 1 through April 1. The report is used by farmers, ranchers, municipal water suppliers, and other water users to help manage limited water supplies.
The snow survey season began Jan. 1, when the NRCS, U.S. Forest Service, National Park Service, and the Navajo Nation began manual measurements of snow depth and snow water content at 38 measurement sites across northern and eastern Arizona.