River flows – how low can they go? | VailDaily.com

River flows – how low can they go?

Cliff Thompson

For many Eagle County residents, the dearth of water here will manifest itself in lawn-sprinkling restrictions that could get more stringent as the summer progresses. Much of the county will be observing an alternate-day irrigating schedule, and towns throughout the county are imposing watering restrictions.

Most Eagle County residents depend on potable water from water districts or municipalities. All of those have reported adequate supplies for summer and fall, provided some water use restrictions are observed. The earlier-than-normal disappearance of the snowpack and the resulting low flows of the rivers, however, signal the beginning of a dessicating routine that will progressively get worse through the summer.

Low flows

– The gauging station at Avon’s wastewater treatment plant Friday indicated flow in the Eagle River was 711 cubic feet per second, or cfs – just 30 percent of the annual mean of 2,310 cubic-feet-per-second.

– At Gypsum it was 1,480 feet, or 44 percent of the 2,091 cfs mean flow.

– At Dotsero, the Colorado River, which is affected by both diversion and augmentation from reservoirs, the flow Thursday was 1,480 cubic-feet per-second, just 23 percent of the annual mean of 6,599. By comparison, in the record big snow year of 1984, when snow piled up to the highest levels ever measured, the Dotsero gauge measured the flow at 17,000 cubic-feet-per second.

– Gore Creek, meanwhile, was running Friday at 309 cubic-feet-per second, just 41 percent of the 756 cubic-feet per-second mean flow.

Why so low?

Part of the reason the river flow is low is that upstream reservoirs on the Eagle, such as Eagle Park and Homestake, are storing water. The same is happening on the Colorado and its tributaries at Dillon, Green Mountain, Wolford and other reservoirs.

“They’re storing every drop the can right now,” said Water Commissioner Bill McEwan of Eagle. “It’s going to be a severe year.”

The numbers validate what the drought warnings predicted – it’s heading toward the driest year on record, unless rains of biblical proportions occur. This surpasses the previous driest year of 1977.

The drought comes after below-normal winter snows. At its height, the snowpack in Eagle County was 52 percent of normal, but that dwindled as the snows of March and April deposited far less than normal and persistent wind further slimmed the snowpack.

There is some good news, however, at least locally. The amount of surface water in the Eagle River basin is the state’s second-best, behind the Yampa, which is flowing at 44 percent of normal near Craig. Heavy localized snows at the headwaters of the Yampa brought snowpack there closer to average this winter than anywhere else in the state.

By comparison, there’s the Animas River, in southwestern Colorado, which essentially has dried up; and the flow of the San Juan River at Mexican Hat, above its confluence with the Colorado, is approximately 11 percent of normal.

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