As Colorado Springs Utilities braces to absorb hundreds of thousands of new residents in the coming decades amid hotter weather, it is looking to conservation, agriculture, and new water supplies from the Colorado and Arkansas rivers to help fill the gap.
Utilities examined 50 future climate scenarios to prepare its latest 50-year plan and settled on a future that will be on average 3 degrees Fahrenheit warmer with no change in average precipitation, instead of relying on historical weather trends to make projections, said Kevin Lusk, a water engineer with Utilities.
“We have designed around a reasonable future that we believe is possible,” he said.
As new neighborhoods take shape, particularly in Banning Lewis Ranch, Utilities is planning for the city's population to increase 53% from about 470,000 people to 723,000, the 50-year plan states. As those residents move in, the city's annual water demands are expected to rise from 95,000 acre feet a year to 136,000 acre feet a year. An acre foot of water covers an acre of ground under a foot of water.
The city expects to meet this demand through a combination of conservation, water reuse, agriculture leases and additional water supply from the two major rivers outside the area.
For Colorado Springs, reservoirs are already a key piece of a complex water system that brings 80% of the 95,000 acre feet of water the city uses annually into the area.
The largest amount of new water supply, 90,000 to 120,000 acre feet of water, is expected to come from the new or enlarged reservoirs or water storage within the Arkansas River basin, according to the 50-year plan. One of those projects could be a new reservoir or gravel pit complex between Twin Lakes and Pueblo Reservoirs, the plan states.
Utilities may also build additional reservoir space in the Colorado River watershed, and it is working with Aurora on a highly controversial new reservoir in the Holy Cross Wilderness in Eagle County. The U.S. Forest Service is expected to make a decision soon on whether to permit the exploration of the new reservoir's feasibility.
"As we move into a future where precipitation may become more variable, bigger events but fewer and farther between, you have got to have a way to capture a lot of water fast and then sit on it for when you need it," Lusk said. Utilities had about 2½ years of water in storage as of late January, according to a February report to the Utilities board.
Through conservation, Utilities expects to save 10,000 to 13,000 acre feet of water annually, said Patrick Wells, general manager with Colorado Springs Utilities Water Resources and Demand Management. The city's watering restrictions adopted last year that limit outdoor watering to three days a week from May 1 to Oct. 15 are meant to help achieve long-term water savings and more than 550 acre feet of water was saved in the first year, he said.
In the future, water owned by agricultural interests, particularly farmers and ranches in the Lower Arkansas River basin, will also play a key role. But rather than purchase it outright, Utilities is looking to lease 15,000 to 25,000 new acre feet of water annually.
The leases are a move away from purchasing farms and their associated water rights outright and transferring that water to the city, a practice called buy and dry. In the 1970s, farmers sold the water rights that previously served 45,000 acres in Crowley County leaving only 5,000 acres in production, The Gazette reported previously.
Cities bought water outright from agriculture through the early 2000s as the primary means of transfer, said Scott Lorenz, water sharing senior project manager with Colorado Springs Utilities.
Now, the state and city are focused on lease agreements that can serve farmers in dry times, he said. For example, in a dry year a farm may not have enough water to put all the fields in production, the producer can lease some water to the city and earn money through the water instead, Lorenz said.
Compensating farmers for their water and taking land out of production can have consequences, however, because it can disrupt the overall agriculture market when farmers aren't buying seed or materials or employing laborers, said Brad Udall, senior water and climate research scientist at Colorado State University. The buyers the farms supply may also go elsewhere for products if farms aren't producing annually, he said.
Utilities' already has several lease agreements in place, including one in perpetuity with the Lower Arkansas Water Management Association, a group that replaces the water taken from the Arkansas River through wells. As farmers pump from ground wells supplied by the river, the association ensures water flows back into the river so that downstream residents in Kansas receive their full water rights.
The city has agreed to lease water from the association five out of every ten years and pay for its water every year, said Bill Grasmick, association president. The city also paid for a new reservoir that the association is already using.
“It’s really a win-win,” he said.
Pumping from groundwater wells made possible by the association is key for farmers to make it through dry times, said Paul Casper, a farmer and association member in Otero County.
“It gives you so much more opportunity to get that crop raised,” said Casper, who raises hay, alfalfa, grass and corn.
The supplemental water could be critical if spring snows don’t show up this year to help temper the severe drought conditions, he said.
“We could very well be setting ourselves up for a 2002 and 2012 event,” he said. Both of those years are recent benchmarks for how bad drought conditions can get in the state.
But many farmers on the eastern plains also learned from those conditions and adopted new, more efficient irrigation methods to replace flooding their fields, such as drip irrigation or center-pivot sprinklers, he said.
“Our irrigation efficiencies are probably the most useful tool we have in combating the drought situations,” he said.
Those new efficiencies have set agriculture on Colorado's eastern plains up for success, he said.
“I think we’ve got a lot of future here,” he said.