By Jerd Smith
Castle Rock’s building boom has barely slowed over the past 20 years and its appetite for growth and need for water hasn’t slowed much either.
The city, which ranks No. 1 in the state for water conservation, will still need to at least double its water supplies in the next 40 years to cope with that growth. It uses roughly 9,800 acre-feet of water now and may need as much as 24,000 acre-feet when it reaches buildout.
With an eye on that growth and the ongoing need for more water, Douglas County commissioners are debating whether to spend $10 million in federal American Rescue Plan Act funding to help finance a controversial San Luis Valley farm water export proposal.
Thirteen Douglas County and South Metro regional water suppliers say they have no need or desire for that farm water, according to Lisa Darling, executive director of the South Metro Water Supply Authority. [Editor’s note: Lisa Darling is president of the board of Water Education Colorado, which is a sponsor of Fresh Water News]
“It is not part of our plan and it is not something we are interested in,” said Mark Marlowe, director of Castle Rock Water. “We have invested hundreds of millions of dollars in our long-term plan and we are pursuing the projects that are in that plan. The San Luis Valley is not in the plan.”
Renewable Water Resources, a development firm backed by former Colorado Gov. Bill Owens and Sean Tonner, has spent years acquiring agricultural water rights in the San Luis Valley. It hopes to sell that water to users in the south metro area, delivering it via a new pipeline. In December, RWR asked the Douglas County commissioners for $10 million to help finance the $400 million plus project.
Tonner did not respond to a request for comment for this article, but he has said previously that the water demands in south metro Denver will be so intense in the coming decades, that the San Luis Valley export proposal makes sense.
Opposition to the export plan stems in part from concern in the drought-strapped San Luis Valley about losing even a small amount of its water to the Front Range. But RWR has said the impact to local water supplies could be mitigated, and that the proposed pipeline could help fund new economic development initiatives in the valley.
Stakes for new water in Douglas County and the south metro area are high. In addition to demand fueled by growth, the region’s reliance on shrinking, non-renewable aquifers is putting additional pressure on the drive to develop new water sources.
Marlowe and other water utility directors in the region have been working for 20 years to wean themselves from the deep aquifers that once provided clean water, cheaply, to any developer who could drill a well. But once growth took off, and Douglas County communities super-charged their pumping, the aquifers began declining. Because these underground reservoirs are so deep, and because of the rock formations that lie over them, they don’t recharge from rain and snowfall, as some aquifers do.
At one point in the early 2000s the aquifers were declining at roughly 30 feet a year. Cities responded by drilling more, deeper wells and using costly electricity to pull water up from the deep rock formations.
Since then, thanks to a comprehensive effort to build recycled water plants and develop renewable supplies in nearby creeks and rivers, they’ve been able to take pressure off the aquifers, which are now declining at roughly 5 feet per year, according to the South Metro Water Supply Authority.
The goal among Douglas County communities is to wean themselves from the aquifers, using them only in times of severe drought.
Ron Redd is director of Parker Water and Sanitation District, which serves Parker and several other communities as well as some unincorporated parts of Douglas County.
Like Castle Rock, Parker needs to nearly double its water supplies in the coming decades. It now uses about 10,000 acre-feet annually and will likely need 20,000 acre-feet at buildout to keep up with growth.
Parker is developing a large-scale pipeline project that will bring renewable South Platte River water from the northeastern corner of the state and pipe it down to the south metro area. Castle Rock is also a partner in that project along with the Lower South Platte Water Conservancy District in Sterling.
Redd said the San Luis Valley export plan isn’t needed because of water projects, such as the South Platte Water Partnership, that are already in the works.
“For me to walk away from a project in which we already have water, and hope a third party can deliver the water, just doesn’t make sense,” Redd said.
The costs of building two major pipelines would also likely be prohibitive for Douglas County residents, Redd said.
“We would have to choose one. We could not do both.”
Steve Koster is Douglas County’s assistant planning director and oversees new developments, which must demonstrate an adequate supply of water to enter the county’s planning approval process.
Koster said small communities in unincorporated parts of the county reach out to his department routinely, looking for help in establishing sustainable water supplies.
He said the county provides grants for engineering and cost studies to small developments hoping to partner with an established water provider.
“All of them are working to diversify and strengthen their water systems so they are sustainable. Having a system that encourages those partnerships is what we’re looking at,” Koster said.
Whether an RWR pipeline will play a role in the water future of Douglas County and the south metro area isn’t clear yet.
Douglas County spokeswoman Wendy Holmes said commissioners are evaluating more than a dozen proposals from water districts, including RWR, and that the commission has not set a deadline for when it will decide who to fund.
Jerd Smith is editor of Fresh Water News. She can be reached at 720-398-6474, via email at jerd@wateredco.org or @jerd_smith.
Fresh Water News is an independent, nonpartisan news initiative of Water Education Colorado. WEco is funded by multiple donors. Our editorial policy and donor list can be viewed at wateredco.org.
The Water Desk’s mission is to increase the volume, depth and power of journalism connected to Western water issues. We’re an initiative of the Center for Environmental Journalism at the University of Colorado Boulder. The Water Desk launched in April 2019 with support from the Walton Family Foundation. We maintain a strict editorial firewall between our funders and our journalism.
