DENVER-The latest measurements of mountain snowpack, conducted by the USDA – Natural Resources Conservation Service (NRCS), indicate that Colorado’s statewide totals continue to track above average. The April 1 surveys show statewide snowpack is 113 percent of average, and is 28% above the state’s readings of one year ago. Although these statistics show a slight decline from last month, they continue the trend of above average totals measured throughout the winter of 2011. This is good news for the state’s major water users who rely on melting snowpack for a majority of their annual surface water supplies.
March weather brought a continuation of the La Niña pattern where most of the storms crossing the state favored the northern mountains, while only dusting the southern mountains, according to Allen Green, State Conservationist with the NRCS. As a result, snowpack readings across the northern and central mountains saw significant increases in snowpack percentages, while percentages declined sharply across the southern mountains. “It was a month where the rich got richer and the poor just got poorer”, said Green.
For those river basins with their source in the northern mountains, including the Colorado, Yampa, White and South Platte Rivers, this year’s April 1 snowpack is the highest since back in 1996. At 135 percent of average, the North Platte River Basin had the highest basinwide total in the state. These totals are the highest for April 1 since the computation of basinwide totals began in 1968. The outlook for spring and summer water supplies in these river basins is excellent this year. Seasonal runoff volumes are anticipated to be well above average, and this year’s flows are expected to be drastically different than last year which was plagued by low runoff.
Meanwhile, the latest readings show snowpack conditions across the southern mountains continued to decline for the third consecutive month. Percentages have now declined to the lowest readings of the year and are consistently below average in the Rio Grande and combined San Juan, Animas, Dolores, and San Miguel basins. In striking contrast to the snowpack readings across northern Colorado, some smaller tributary basins in the Rio Grande Basin have dropped to nearly 50 percent of average. As one might expect, the outlook for spring and summer water supplies across southern Colorado is for below average runoff throughout the Rio Grande, San Juan, Animas, Dolores, San Miguel and the southern tributaries of the Arkansas basin this year. While it’s still possible for spring snowstorms to improve conditions in these basins, the chances are extremely remote, given that the normal maximum snowpack is reached in early April in these basins.