Big snows in January, February boost snowpack to nearly normal
Snow provides 90% of Denver’s water supply. Keep the snow train coming!
Storms that dumped several feet of snow in Park, Summit and Grand counties in January and February left behind great skiing conditions and a sorely needed boost to the mountain snowpack.
Entering 2024, the snowpack in the areas of the South Platte and Colorado river basins where Denver Water captures snow for its water supply were well below normal due to relatively dry weather in November and December 2023.
But storms in mid-January and early February boosted mountain snowpack in the two river basins to nearly normal for this point in the season.
As of Monday, Feb. 5, the snowpack in Denver Water’s collection areas stood at 106% of normal in the South Platte Basin and 98% of normal in the Colorado River Basin.
“January was great in terms of our water supply. In fact, the snowpack accumulation was nearly double the average for the month,” said Nathan Elder, water supply manager at Denver Water.
“We are right at normal for the season, and we’re hopeful the stormy weather pattern continues as we head into the snowier months of the year.”
The blue line on the charts below shows how a few big storms can quickly boost a very low snowpack (close to the bottom of the grey area) up to the black or "normal" line:
Monitoring the snow
Denver Water pays close attention to the snowfall in the mountains because snowmelt provides 90% of the water supply for 1.5 million people in its service area across metro Denver.
The utility monitors the snowpack in multiple ways through the season.
Once a month, January through April, Denver Water crews snowmobile and snowshoe through the snow to collect about a dozen samples of the snowpack along preestablished paths through the wilderness called “snow courses.”
Denver Water has snow courses at 11 locations in Grand, Park and Summit counties.
Capturing snow samples looks like spear-fishing. Crews jab a specially designed hollow pole into the snow until it hits the ground. The pole measures the snow depth and weight which is then used to determine the snow’s density.
This information is then used to calculate the snow water equivalent, or SWE. In simple terms, it’s the depth of water that would cover the ground if all the snow melted.
“Ski areas love that champagne powder, but we like to see snow with lots of water inside,” said Rick Geise, a facility operator at Dillon Reservoir in Summit County. “The more water packed into the snow, the more water that flows into our reservoirs in the spring when all the snow melts.”
Denver Water shares the data collected from its snow courses with the National Resources Conservation Service, which puts out statewide snowpack and water supply information.
The utility also uses information gathered from automated mountain weather stations called SNOTEL sites, which are managed by the NRCS.
Denver Water also gets information on the snowpack from the air, via flights from a company called Airborne Snow Observatories, which uses advanced technology to measure snowpack from the sky.
“We use the data to make sure we have a good idea about the amount of water in the snow up in the mountains,” Elder said.
“These tools give us very good picture of the snowpack so we can provide accurate water supply forecasts for our customers and the general public.”