PHOENIX, April 16, 2013 - The Arizona Basin Outlook Report released this month by USDA’s Natural Resources Conservation Service (NRCS) shows the state snowpack to be well below average levels. The federal agency monitors snow conditions in Arizona’s mountain watersheds each winter to estimate the amount of water available for spring and summer uses.
“This is the third winter in a row of below normal snowpacks in the mountains of northern and eastern Arizona,” said Dino DeSimone, State Water Supply Specialist with the NRCS in Phoenix, Arizona. “As of today, nearly all of our snow measurements sites have melted out, which is about a month earlier than normal. As a result, runoff in the state’s major rivers is again expected to be at extremely low levels.”
Among the findings in the Basin Outlook Report, the Salt River basin snowpack was measured at 29 percent of the 30-year median; the Verde River basin at 71 percent of median; the San Francisco-Upper Gila basin at 29 percent of median; and the southern headwaters of the Little Colorado River basin had 53 percent of median snowpack. In the Chuska Mountains of northeastern Arizona, snowpack conditions were measured at 73 percent of median.
The current streamflow forecast calls for well below normal runoff for the remainder of the forecast period through May. Flows are expected to be only 37 percent of median on the Gila River; 32 percent on the Salt River; 69 percent on the Verde River; and 29 percent on the Little Colorado River. The Colorado River inflow to Lake Powell, which reflects snowpack conditions in the Upper Colorado River Basin, is estimated at only 34 percent of average for the forecast period April-July.
As of April 1st the six Salt River Project reservoirs held a combined total of 1,447,000 acre-feet (a-f) in storage at 63 percent of system capacity. San Carlos reservoir held 11,100 a-f storage, which is only one percent of capacity. Storage in Lyman Lake was 5,100 a-f. The combined storage of Lake Mead and Powell on the Colorado River was 25,123,000 a-f, which is 50 percent of combined capacity. An acre foot of water equals 325,851 gallons and is enough to supply a family of five for a year.