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How we know how much water is in that snow

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Measuring Snowpack
Denver Water’s collection system covers about 4,000 square miles. Our experts work as a team to gather and analyze information about the snowpack. Photo credit: Denver Water.

March typically is one of Colorado’s snowiest months. And how much snow falls in the high country can set the tone for Denver’s water supplies for the rest of the year.

Keeping track of how much snow has fallen — and how much water it holds — is a team effort From January through May, Denver Water crews make a monthly trek into the wilderness to measure snow at 11 locations in Grand, Park and Summit counties. They hike, snowshoe, cross-country ski and ride in snowcats to reach the designated measuring sites.

They carry special hollow tubes that are jabbed into the snow until the end hits the ground and the tube captures a sample, which is measured for the depth and weight of the snow.

That information is used to determine the snow-water equivalent: a calculation of how much water is contained in the snow.

“A general rule of thumb is that 12 inches of fresh snow equals about 1 inch of water when it melts,” said Nathan Elder, Denver Water’s manager of water supply.

Denver Water also uses information collected by the Natural Resources Conservation Service’s automated snowpack telemetry weather stations, known as SNOTEL sites. The network of stations was established in 1979 and provides real-time snow information at locations across Colorado and the Western U.S.

The manual and automated readings provide Denver Water’s planners with a better picture of what’s on the ground now and what we might expect for supply.

Learn more about the importance of snowpack for Denver’s water supply.

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How much water is in Colorado’s snow can set the tone for water supplies for the rest of the year. Photo credit: Denver Water.
How much water is in Colorado’s snow can set the tone for water supplies for the rest of the year. Photo credit: Denver Water.