The location of a potential dam on upper Maroon Creek, just below the confluence of East and West Maroon creeks. The reservoir would have a view of the Maroon Bells.
The location of a potential dam on upper Maroon Creek, just below the confluence of East and West Maroon creeks. The reservoir would have a view of the Maroon Bells. Smith / Aspen Journalism Credit: Brent Gardner-Smith / Aspen Journalism

ASPEN – Tall new dams in pristine spots on upper Castle and Maroon creeks.

Bigger dams on Lost Man and Lincoln creeks in the headwaters of the Roaring Fork River.

A bigger reservoir at the city’s water plant.

Water pumped up from deep underneath Aspen.

Treated effluent pumped from the Aspen wastewater plant to the city golf course.

Water left in the river instead of being diverted to the Wheeler irrigation ditch.

These projects are all on a list that Mike McDill, the city of Aspen’s deputy director of utilities, wants included on a larger list of regional water projects now being compiled by the Colorado River Basin Roundtable.

“If it is already on the list, at least people can’t say they didn’t know we were thinking about it,” McDill said.

The roundtable is developing the list of projects for possible inclusion in its “basin implementation plan,” which is to be sent to the Colorado Water Conservation Board (CWCB) by July 15. It’s all part of the development of a statewide water plan designed to close gaps between water supply and demand in 2050.

Over 500 “projects, policies and processes” are now on the Colorado roundtable’s draft priority list, including Aspen’s suggested projects. The list, which is part inventory, part to-do list, and part wish list, is to be winnowed down in the next two months by the roundtable.

“Putting projects on the roundtable’s list is a good way to provoke conversation,” said Louis Meyer, a consulting engineer with SGM, who is leading the development of the Colorado roundtable’s basin plan. “It is also incumbent on us to show the state that we have a list of water needs.”

If a project is included in the roundtable’s basin plan, or ultimately in the Colorado Water Plan, it could give it momentum toward completion.

“Certainly, if something is in the plan, that gives it a boost in importance and that is why we want to vet what’s out there,” said Jim Pokrandt, a communications specialist at the Colorado River District who serves as chair of the Colorado roundtable. “There could be projects that are too pie in the sky.”

Upper Castle Creek, near the location where the city of Aspen is maintaining conditional water rights for a dam and reservoir.
Upper Castle Creek, near the location where the city of Aspen is maintaining conditional water rights for a dam and reservoir. Smith / Aspen Journalism Credit: Brent Gardner-Smith / Aspen Journalism

Building new reservoirs

During recent public roundtable meetings, McDill has described Aspen’s list of projects in a calm and pragmatic matter, despite the scale of some of them.

“Our concern is we have a lot of water in June and not so much water the rest of the year,” McDill said about the potential value of reservoirs on upper Maroon and Castle creeks.

Today the city of Aspen diverts water from lower Castle and Maroon creeks for its water supply, but it does not have any water storage capacity beyond the tiny Leonard Thomas Reservoir at the water plant, which can hold 14 acre-feet of water.

If built someday as described by the city’s conditional water right, the Maroon Creek reservoir would store 4,567 acre-feet of water behind a 155-foot-tall dam just below the confluence of East Maroon and West Maroon creeks, which is known as a stunningly beautiful location.

A Maroon Creek reservoir would cover 85 acres of U.S. Forest Service land about a mile-and-a-half below Maroon Lake.

The Castle Creek reservoir would hold 9,062 acre-feet of water behind a 170-foot-tall dam located about two miles below the historic town site of Ashcroft in a verdant valley. It would inundate 120 acres of mostly private land.

The city has renewed the conditional water rights for the two reservoirs eight times since they were decreed in 1971 and is required to do so again in 2016, when it must show it is making progress toward building the reservoirs.

“Aspen will build the Castle Creek and Maroon Creek reservoirs if necessary and if in the best interest of citizens of the community,” city officials said in 2012.

The city of Aspen is named as the “sponsor” for the two reservoirs on the roundtable’s list of water projects.

The roundtable’s spreadsheet cataloging the potential projects notes that both the Castle and Maroon creek reservoirs would “ensure adequate safe drinking water” and “reduce agricultural water shortages.”

Both are goals of “consumptive” projects to be included in the basin implementation plan.

Grizzly Reservoir on Lincoln Creek, well above its confluence with the Roaring Fork River. The reservoir briefly stores water before it is diverted under the Continental Divide.
Grizzly Reservoir on Lincoln Creek, well above its confluence with the Roaring Fork River. The reservoir briefly stores water before it is diverted under the Continental Divide.Smith / Aspen Journalism Credit: Brent Gardner-Smith/Aspen Journalism / Aspen Journalism

Enlarging existing reservoirs

Also on Aspen’s list of potential projects is the enlargement of existing reservoirs, including Grizzly Reservoir and Leonard Thomas Reservoir.

“Wherever there is one, we should at least put it on the list,” McDill said of local reservoirs.

The city is not shown on the roundtable’s list as a sponsor of the idea of enlarging Grizzly Reservoir, but McDill voiced his support for the concept at a recent roundtable meeting.

“This might be potential mitigation that might affect the Roaring Fork valley,” McDill said about enlarging Grizzly. “It is a possibility.”

Grizzly Reservoir was built in the 1930s on upper Lincoln Creek, a tributary of the Roaring Fork River. The reservoir is owned by the Twin Lakes Reservoir and Canal Co., of which the city of Colorado Springs is now the majority owner.

The reservoir holds about 570 acre-feet of water and primarily serves as the fore bay to the tunnel that Twin Lakes uses to divert water under the Continental Divide.

A 2007 report by Grand River Consulting for the city of Aspen and Pitkin County said Grizzly Reservoir could be re-built to hold 4,600 acre-feet at a cost between $23 and $46 million.

The report also noted that expansion of the reservoir would require complex permitting and that damage to existing wetlands “will be difficult to overcome.”

The smaller Lost Man Reservoir, also owned by Twin Lakes, backs up water on Lost Man Creek and then diverts it to Grizzly Reservoir.

“It’s there and there is some potential to do that,” McDill said about enlarging Lost Man. “A group of cities on the Roaring Fork might contemplate doing so.”

But Kevin Lusk, a principal with Colorado Springs Utilities, and the president of the Twin Lakes Reservoir and Canal Co., threw cold water this week on the idea of expanding either Grizzly or Lost Man reservoir.

“Twin Lakes has no plans or interest in enlarging these facilities,” Lusk said via email. “Nor has anyone talked to us about these ideas.”

Lusk said he also wasn’t aware of studies regarding the enlargement of either reservoir.

“If I had to guess, given their configurations, enlargement would at best be impractical, and likely not feasible,” Lusk said.

Also on the city’s list is expanding Leonard Thomas Reservoir at the city’s water plant above Aspen Valley Hospital so it can hold 25 acre-feet instead of 14 acre-feet.

“We need it bigger,” McDill said of the reservoir.

The note about enlarging the Leonard Thomas Reservoir on the Colorado roundtable’s list says the project is in the “beginning stages of design/permitting.”

The city of Aspen drilled a water well 1,500 feet down last year and found a steady stream of water. Is it potable? Could it be a back-up supply of water for the city?
The city of Aspen drilled a water well 1,500 feet down last year and found a steady stream of water. Is it potable? Could it be a back-up supply of water for the city?Smith / Aspen Journalism Credit: Brent Gardner-Smith / Aspen Journalism

Deep well under Aspen

Another water project on the municipal list is to determine just how much water is under the city of Aspen, and whether it is suitable for drinking.

In 2012 and 2013, the city drilled a water-well near Herron Park 1,520 feet underground in search of hot water it could use for geothermal energy.

But in July 2013 the city announced that it did not find water hot enough to make electricity, but it did find a steady stream of clear water coming up out of the well at 29 pounds per square inch, about half of the water pressure in a normal household.

“This summer, we’re putting a pump into the well to analyze the water and get some feel for the capacity of the aquifer,” McDill said.

If it turns out there is still a lot of water 1,500 feet underground Aspen, the city may install a larger, permanent pump into its test well to create a back-up supply of water.

“What would we do if we had a wildfire that burned through Castle and Maroon Creek and we had soot in our water supply?” McDill asked. “It sure would be nice if we had a back-up supply. We need to start to consider that eventually.”

A worker watering a portion of the Maroon Creek golf course, which would be able to use water from the city of Aspen's pumpback project.
A worker watering a portion of the Maroon Creek golf course, which would be able to use water from the city of Aspen\ Credit: Brent Gardner-Smith / Aspen Journalism

Pump back project

The pump back project, which is well under way, will allow the city to reuse water from the Aspen Consolidated Sanitation District to supplement its irrigation water on the municipal golf course, and to provide irrigation and snowmaking water for other entities, including the Buttermilk Mountain ski area.

“It is intended to keep more water in the Castle Creek by not diverting for the golf course,” McDill said.

The source of the water is “treated municipal effluent” and pipes already have been installed from the sanitation plant, past the Burlingame neighborhood, and to a pond on the city golf course.

The city is still seeking a water right for its pump back project from state water court, and has been working out agreements with a long list of opponents.

The water is to be primarily used to irrigate 12.3 acres of landscaping along Highway 82 and Cemetery Lane, according to documents in water court. It also could supplement irrigation on 131 acres of the Aspen golf course, 21 acres of land in the Burlingame project, and 80 acres of the Maroon Creek golf course.

In all, 233 acres of land could receive water from the project and water could be used to make snow on as much as 156 acres of land at Buttermilk.

The Wheeler Ditch. This is a view looking upriver toward the diversion structure, which is river-left on the Roaring Fork River down the steep hillside from Ute Park, and just downstream from the Aspen Club pedestrian bridge.
The Wheeler Ditch. This is a view looking upriver toward the diversion structure, which is river-left on the Roaring Fork River down the steep hillside from Ute Park, and just downstream from the Aspen Club pedestrian bridge.Smith / Aspen Journalism Credit: Brent Gardner-Smith / Aspen Journalism

Water left in the river

Also on the roundtable’s list is the city of Aspen’s recent effort to keep more water in the Roaring Fork River as it runs through town.

The Fork is often below a flow level of 32 cfs, which is the minimum amount of water the CWCB has determined is necessary to protect the environment “to a reasonable degree.”

Last year, the city entered into a non-diversion agreement with the Colorado Water Trust leave 6 cfs of water in the river instead of diverting the water into the Wheeler Ditch, which is located river-left just downstream of the Aspen Club pedestrian bridge.

The water in the Wheeler Ditch is typically used by the city for landscaping and irrigation in various parts of central Aspen.

“It worked,” McDill said about the effort to leave more water in the river. “It was supposed to be a pilot project.”

This project is more of a policy than a physical project, and it is an example of the city working to preserve the environment of the Roaring Fork River.

“We’re going to at least approach council about doing it again,” McDill said about leasing water to CWCB for environmental purposes. “We’re just taking it one year at a time.”

The Colorado River basin roundtable is scheduled to next discuss its draft list of projects on Monday, April 14, from noon to 4 p.m. at the Glenwood Springs community center.

Editor’s Note: Aspen Journalism’s Water Desk and the Aspen Daily News are collaborating on coverage of water and rivers in the West. The Daily News published a version of this story on Sunday, April 6, 2014.

Brent Gardner-Smith, the founder of Aspen Journalism, and who served as AJ’s executive director until August 2021 and as editor from 2011-2020, is the news director at Aspen Public Radio. He's also been...