Flirting with drought
With Denver on track to have one of its driest winters ever and the mountains seeing below-normal snowfall, Denver Water managers are keeping a close eye on water supply, not only for this summer but also the future.
“Unfortunately, we can’t make more water. That’s why we’re always cautious in our water management decisions and thinking one to three years out,” said Nathan Elder, interim water supply manager at Denver Water. “We constantly review when, where and how much water we’re bringing down from our mountain reservoirs.”
Thanks to foresight of the leaders who developed Denver’s water system, there is a network of 20 reservoirs spread across 4,000 square miles in eight counties that provide water managers of today with a diverse portfolio to collect and store water supplies.
“Having the flexibility to pull water from different reservoirs is helping us right now because we have areas in our water collection system where snowfall is below average,” Elder said.
The snowpack in Denver Water’s South Platte River collection area is only around 76 percent of normal, while the areas feeding Dillon Reservoir in Summit County are right on track for this time of year.
“With more snow in Summit County, we started bringing down water a month earlier than usual through the Roberts Tunnel from Dillon Reservoir,” Elder said. “The move helps us protect the water supply in Cheesman Reservoir, which is part of our drier South Platte system.”
This flexibility has helped put Denver Water in a pretty good spot heading into this runoff season.
“Our reservoir storage is actually higher than normal for this time of year, thanks in part to our customers’ efficient water use,” said Elder. “That said, the dry conditions across the entire state are concerning, which is why we’re closely monitoring runoff projections, precipitation, snowpack, stream flows, wind and soil moisture and long-range weather forecasts.”
Having multiple reservoirs also gives water managers opportunities to store water from wet years so it’s available during dry times.
“We had to use all the water in Antero and half the water in Eleven Mile Canyon to get through the drought of 2002-2004,” Elder said. “It can take several years to refill a reservoir, which is one of the reasons why we’re always smart with our water supplies and asking customers to use water efficiently.”
Juggling water in multiple reservoirs is one piece of a complex puzzle that water managers work with on a daily basis, whether it’s a dry, normal or wet year.
“Every water management decision we make depends on more than snowpack and reservoir levels,” Elder said. “We have to incorporate a variety of factors, including water rights, environmental and recreational impacts, infrastructure maintenance and upgrade projects, and fluctuating water demand from our customers.”
“We live in a dry climate, so we know the next drought is always right around the corner,” said Greg Fisher, water demand planning manager at Denver Water. “If conditions warrant, we have a drought response plan ready to go which outlines water use rules and restrictions for our customers to help us manage our mountain water supplies.”