ASPEN – The city of Aspen has applied for an underground water right for a new well across from Herron Park on Queen Street, where it drilled a test well in 2011 and 2013 searching for a geothermal energy source.
The city drilled down 1,520 feet and found that while the water sitting in an underground aquifer in the Leadville Limestone formation was warm, at 90 degrees, it was not hot enough for a geothermal project.
Hot or not, the city still found a significant source of water, that it may want to tap someday.
“There is a very substantial quantity of water available,” said Phil Overeynder, a water resources engineer with the city of Aspen.
A report prepared by Rocky Mountain Water Consulting, LLC in 2008 for the city about the geothermal potential suggested as much.
“Regionally, the Leadville Limestone is recognized as a major aquifer, which has the capacity to yield hundreds to thousands of gallons per minute (gpm) to wells,” the report stated.
The report also cited a 1935 study that reported “as much as 3,250 gpm (7.24 cubic feet per second) were pumped from the underground mine workings beneath Smuggler Mountain during peak runoff,” back when silver miners in Aspen were trying remove the water in mine shafts that reached 1,200 feet below the river.
As the city finished its test well in 2013, it found water flowing up from the deep underground aquifer at 30 pounds per square inch, suggesting it would not take much pumping to secure a steady flow of water.
Under state regulations the well the city previously drilled is a “monitoring well,” meaning it can be used to test water, but not for municipal pumping purposes.
Water could backstop Castle and Maroon supplies
The city filed its water rights application in Division 5 water court in Glenwood Springs on Dec. 31, 2015.
It’s seeking a conditional right to take 3.3 cubic feet per second (cfs) from a new “Aspen Queen Street Well” that would be drilled as deep as 3,000 feet down if necessary.
The well would be located 200 feet from the existing monitoring well in the parking lot next to the Prockter Open Space parcel, which borders the north bank of the Roaring Fork River just above the No Problem Joe Bridge in central Aspen.
The city spent $300,000 on drilling the existing monitoring well. The drilling process, which included drilling two holes, was loud and caused significant consternation among residents in the immediate neighborhood, which includes a number of high-end rental properties.
The city’s application says a new well could still be used for geothermal purposes in accordance with another water right decreed in 2008, but the water is mainly envisioned as a back-up source of municipal water supply.
“It could be that in some of the scenarios with climate change we could be looking at the need to have other sources of supply to back up Castle and Maroon creeks, either in an emergency or drought,” Overeynder said, noting that the new well and potential back-up supply is part of the city’s longterm water planning outlook.
The city’s main sources of water today are Castle and Maroon creeks, both of which have stream-wide diversion dams across them that send water toward the city’s water treatment plant above the hospital.
The city’s water rights application says that the new well water “will be available to address emergencies such as damage or failure of surface diversion infrastructure, fire-fighting needs, and impairment of water quality or quantity at surface diversion structures as a result of fire, avalanche, drought or other conditions.”
On Saturday, February 20, 1993, avalanches thundered across upper Castle and Maroon creeks and almost completely blocked the flow of water in the creeks. The city ordered residents to conserve water to make its remaining 24-to-48 hour supply of water last, according to the Associate Press.
Then Pitkin County Sheriff Bob Braudis was quoted by the AP as saying “I think we have adequate water in the system. If not, if it dries up, our biggest concern is structure fires. We won’t have any water for structure fires.”
The application also says the well water may be put to a wide variety of other uses, “including but not limited to geothermal heat, domestic, fire protection, commercial, industrial, snowmaking, recreational, [fisheries], wildlife, irrigation, freshening, aesthetic, water quality purposes … , augmentation, replacement and substitution, exchange, recharge and storage for subsequent use.”
The application notes that the potential well’s source is “underground water in the Leadville Limestone formation” and that the water is “tributary to the Roaring Fork River.”
Given that the underground water is connected to the flow of the Roaring Fork River, the burden is on the city to show that its new water right would not damage existing water rights.
“We are going to have to be able to demonstrate that our use of that supply, even if it is intermittent or emergency use, still protects all the other water rights holders around us, including the instream flow,” Overeynder said.
The Colorado Water Conservation Board, or CWCB, holds a 1976 instream flow right to 32 cfs of water in the Roaring Fork River between Difficult Creek and Maroon Creek. That level of water is meant to “protect the environment to a reasonable degree.”
New water rights in the Roaring Fork drainage typically have to show a source of augmentation, or back-up, water that can be used to protect senior rights in the event of low flows.
The city addressed the need for an augmentation plan in its water rights application and pointed to a number of sources that could be used in such a plan, including 400 acre feet of water it owns in Ruedi Reservoir.
That water could offset a call from senior water rights holders, at least below the confluence of the Fryingpan and Roaring Fork rivers in Basalt.
The CWCB filed a statement of opposition Feb. 19 in the city’s water court case. Such filings can be routine, but the state does express concern about the city’s suggested augmentation plan.
“The proposed plan for augmentation and exchange may not replace depletions in the proper time, place and amount, which could injure CWCB’s instream flow water rights,” the CWCB’s statement of opposition says.
The city’s application also includes a request to divert an additional 1 cfs of water out of the Roaring Fork River into the Riverside Ditch, on top of its current right to divert 3 cfs. The water would be used to irrigate the Prockter Open Space, Herron Park and Newbury Park, among other uses. And the city seeks the right to store 1.5 cfs of water in Snyder Pond, which is in Snyder Park on Midland Ave.
The window for other parties to file statements of opposition in the case (2015CW3119) has been extended, due to a public notice mistake, until March 31.
Editor’s note: Aspen Journalism and the Aspen Daily News are collaborating on coverage of rivers and water. The Daily News published this story on Saturday, Feb. 27, 2016.
Prior coverage by the Aspen Daily News of the city’s geothermal efforts: