Snowpack above 30-year average
Normal spring runoff expected

Copyright © 2009
Gallup Independent
By Diné Bureau

PHOENIX — Water resources specialists from the Natural Resources Conservation Service and cooperating partners are reporting that snowpack levels in Arizona’s river basins are well above normal, ranging from 131 percent to 334 percent of average.

Despite the heavy early snowpack, however, the long-range forecast calls for normal to below normal streamflow levels for the spring runoff period.

The snow survey season began Jan. 1 when specialists with the Natural Resources Conservation Service , U.S. Forest Service, National Park Service, and the Navajo Nation took the first of many manual measurements of snow depth and snow water content at 23 snow courses across northern and eastern Arizona. The same locations are measured each year, for over 50-years in some locations.

Statewide, the Jan. 1 snowpack measured at 248 percent of the 30-year average, compared with 98 percent a year ago. The Chuska Mountains were at 265 percent, the Grand Canyon at 196 percent, San Francisco Peaks at 195 percent and Central Mogollon Rim, 286 percent.

The Verde River Basin snowpack was measured at an impressive 334 percent of the average for this time of year.

“Several major snowstorms during the latter half of December resulted in the heavy snowpack we now see throughout the mountains of northern and eastern Arizona,” said Dino DeSimone, water resources specialist for the conservation service.

On the Salt River near Roosevelt, the runoff forecast calls for 100 percent of median streamflow levels, or 385,000 acre-feet for the January-May forecast period. On the Verde River at Horseshoe Dam, the long-term runoff prediction calls for 86 percent of median streamflow levels, or 190,000 acre-feet for January through May.

As of Jan. 1, the combined Salt River Project SRP system is at 90 percent of capacity with 2,072,000 acre-feet in storage. The SRP system covers the Verde and Salt River watersheds and includes six reservoirs; Horseshoe and Bartlett on the Verde River, and Roosevelt, Apache, Canyon, and Saguaro on the Salt River. At San Carlos, reservoir storage stands at 217,000 acre-feet, or about 25 percent of capacity.

The Natural Resources Conservation Service makes 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.

Data on snow water content, total precipitation and air temperature are also collected daily from Arizona’s 18 SNOTEL (snow telemetry) sites. The data collected by the SNOTEL system is transmitted by radio signals, which bounce off meteor trails 50 miles above the earth.

The NRCS and its cooperative snow surveyors have been measuring snowpacks and estimating spring runoff in Arizona since 1935.

Information: http://www.az.nrcs.usda.gov/snow