Worst-case winter water plan awaits | VailDaily.com

Worst-case winter water plan awaits

Cliff Thompson

That worst-case scenario – which they hope will not happen – is a continued drought and bitter cold that could freeze the water in the Eagle River and Gore Creek, leaving water treatment plants virtually high and dry.

“We’re hoping there will be water in the river,” said Steve Wilson, water manager for the Eagle River Water and Sanitation District.

Sept. 7, the river at Avon reached a low flow of 26 cubic feet per second, or cfs, before a series of storms bolstered flows. Friday, the river was flowing at 124 cfs, 99 percent of the long-term average.

That reprieve, however, is likely temporary, said hydrologist Bob Weaver, adding that the ground has been dry for so long that when it stops raining, the river drops quickly.

Wilson and others have created a 100-day drought management plan for the most critical time – Dec. 1 to mid-March- spanning the depth of winter and the begining of snowmelt. It is then that the river reaches its lowest flows and is most liable to freeze.

That plan marshals reservoir supplies, subsurface water, treated wastewater and available streamflow to make it available for consumption.

The outflow of wastewater treatments plants in Vail and Avon will supply up to 47 percent of the available water in a worst-case scenario, the plan shows. The drought management plan is designed to meet the domestic needs of nearly 22,000 water users from East Vail to Wolcott. A new $12- million Edwards water treatment plant is expected to be online later this month, and it can be used to split the water treatment duties.

That’s significant, Wilson said..

“It will help the streamflows. Instead of the Avon plant taking all the streamflows, we will split the use and keep water in the stream longer.”

The available worst-case water supply this winter, based on current estimates, is 12.14 cfs, or enough for nearly 40,000 people.

To help keep the volume of water in the river large enough to prevent it from freezing, the plan proposes coordinating upstream reservoir releases by water owners. If they can be staggered so flows remain higher, longer, that could keep the river from freezing.

Another portion of the contingency plan calls for operating drinking water treatment plants at lower capacities for more hours each day, to help keep the flow of the river higher.

When the treatments plants are not operating, from 3 a.m. until 6 a.m., well water would augment supplies.

The plan calls for upgrading three wells in Edwards so they will produce a combined 1 million gallons per day and reduce demand on the river by 1.55 cfs, or 850 gallons per minute. That project will cost $50,000 to $80,000, Wilson said.

Last summer, water users from East Vail to Wolcott, the area served by The Eagle River Water and Sanitation district and the Upper Eagle Regional Water Authority, faced lawn-watering restrictions and stiff fines for most of the summer. They were lifted for the area between Wolcott and Dowd Junction in mid- September when frost ended the growing season.

Whether or not the plan is implemented is literally up to the vagaries of the weather.

“We’ll throttle it down according to the river and the demand,” Wilson said.

September precipitation above normal

September’s weather brought much-needed precipitation, but it has not broken the unprecedented drought that has water managers making “worst-case scenario” plans.

Avon weather watcher Frank Doll recorded 3.11 inches in September, nearly 1.5 inches above the norm. That heavy rain, and higher up, snow, has bolstered the dwindling flows of local streams, bringing the Eagle River from 26 cubic feet per second to 120 cfs this week.

The precipitation happened in the midst of the worst drought experienced by the area in 125 to 500 years, according to tree-ring analysis.

“We had a lot of rain. Other than the precipitation, it was not a bad month,” said Doll, who has been making and keeping weather records for 25 years.

The wettest September on record was in 1985, when 3.59 inches were recorded.

Temperatures were normal, with the warmest temperature, 85 degrees, Sept. 5; the coldest, 34 degrees, came Sept. 20 and 22.

The average high was 70 degrees; average low was 41 degrees.

Cliff Thompson can be reached at 949-0555 ext 450 or cthompson@vaildaily.com.

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