From The Watch (Peter Shelton):
Water managers care only about the snow-water equivalent – what snow hydrologist Mark Rikkers calls the “snow bank.” How much water is up in the high country that can be counted on to flow into rivers, irrigate crops, fill reservoirs and recharge watersheds?
They measure the water stored in snow by river basin: the Upper Colorado River Basin, the Gunnison, the Dolores/San Miguel, the Yampa/White. And so far this water season the numbers aren’t looking great. “Pray for a good monsoon,” said Tri-County Water Conservancy District General Manager Mike Berry recently. “If we don’t have a wet spring, and rain in July and August, we’re going to be in trouble.”
Tri-County manages nearly all the water in the Ridgway Reservoir.
Right now, according to Phyllis Ann Philipps, the Colorado State Conservationist with the Natural Resources Conservation Service, the state has only received 73 percent of average snowfall (averaged for the last 30 years). And that number is just 83 percent of last year’s snowpack, as of March 1.
Reservoir storage statewide is at 71 percent of average, and 67 percent of the levels recorded last year. Reservoir levels were higher last spring after a snowy 2011, but many had to be drawn down significantly during the dry spring and summer of 2012. Berry estimated it would take springtime snow and rain (from now until the beginning of irrigation season) on the order of 130-140 percent of average in order to “bring us up to 100 percent.”
The southwest region is actually doing better than some other parts of the state. The combined San Miguel, Dolores, Animas and San Juan basins, as of March 1, have 83 percent of their normal snowpack. The big Eastern Slope basins, the Arkansas, South Platte and North Platte, are averaging 70 percent of normal between them. And normal, according to Rikkers (and corroborated by Berry) is changing. Every year, the 30-year average drops the oldest-year data and moves ahead one year. And as the climate is warming and drying, the average is warming and drying too. So, our 83 percent is relative to the average since 1983. Old timers will remember decades when “average” was considerably wetter.