Editor’s note: The following is the first part in a series exploring the city of Aspen’s historic intent in filing for and maintaining conditional water rights for storage reservoirs on Castle and Maroon creeks.
ASPEN – Thursday will mark the date 51 years ago when two maps were filed with the state of Colorado by the city of Aspen, signaling the city’s intent to someday build two large dams and reservoirs on upper Maroon and Castle creeks.
It was on Dec. 29, 1965, that the maps pinpointing the location of the two potential dams, their height, and the size of the resulting reservoirs were filed with the state water engineer’s office. Aspen’s mayor at the time, Harald Pabst, signed both maps.
One map, in its notes section, described a 155-foot-tall dam within view of the Maroon Bells that would create a reservoir holding 4,567 acre-feet of water. The other map described a 170-foot-tall dam two miles below Ashcroft that would hold 9,062 acre-feet.
On Oct. 31 of this year, the city filed applications with the state to extend the conditional water rights for the two potential dams and reservoirs for another six years.
It was the ninth time the city has filed for diligence on the reservoirs since 1972. This was the first time the reservoirs were separated out into two applications, one for Maroon Creek Reservoir and one for Castle Creek Reservoir.
Pitkin County, American Rivers, and the U.S. Forest Service have all stated publicly they intend to file statements of opposition in the cases, which are being processed in Division 5 water court in Glenwood Springs, before the Dec. 31 deadline. Wilderness Workshop, Western Resource Advocates, and a property owner on whose land the Castle Creek dam would be built filed statements of opposition last week.
During deliberations this fall by Aspen City Council about the conditional water rights tied to the two dams, it sometimes sounded as if the current council members viewed the old water rights as orphans once left on the doorstep of city hall by distant strangers.
“As far as where the 150-foot-dam picture comes from, was that us, or someone else?” said Aspen City Councilman Adam Frisch during a Sept. 20 work session on the water rights. “All I know is 150 feet keeps on getting talked about in print from some very smart and well-meaning organizations, so I’m assuming it came from somewhere.”
David Hornbacher, the city’s director of utilities and environmental initiatives, confirmed for Frisch that the heights of the two dams — 155 feet tall at Maroon Creek Reservoir and 170 feet tall at Castle Creek Reservoir — came from the two maps signed by Aspen’s mayor in 1965 and filed with the Colorado state engineer’s office by the city’s consulting engineer.
“In 1965, maps were prepared,” Hornbacher said. “And those maps showed physically where these conditional water rights would be. It would show the depth. Based on the depth, what the volume of water is. So the height is directly off of that information that was filed back in 1965.”
And the rights have been nurtured ever since, although with a parenting philosophy that could be described as “benign neglect.” The city has never done a feasibility study for either dam and reservoir project. And yet, it has consistently told the state it intends to build both dams when needed.
Now at 51 years of age, it’s still not clear if the water rights will ever mature to fruition. But the city announced on Halloween it is still willing to care for them. And in so doing, the city once again told the state the dams are vital components of its integrated water system and that it will build the dams if it needs to, especially in light of climate change.

Council approved
The date of Dec. 29, 1965, is relevant because that’s the day the city filed official maps with the state engineer’s office in Glenwood Springs for the dams on Castle and Maroon creeks. The maps are clear and compelling, and include both the mayor of Aspen’s signature and that of Dale Rea, the city’s consulting engineer.
While the maps were filed in December 1965, the water right itself carries an earlier appropriation date of July 19, 1965. That’s the day on which the Aspen City Council confirmed staff’s initiative to have Rea locate the two dam sites and prepare maps to file with the state. That direction from the council is viewed as the first step taken under Colorado water law to create the water rights for the two dams.
John Kerrigan was the city manager, or administrator, in 1965 and he obtained the council’s consent for Rea to proceed, according to minutes from a regular city council meeting held on July 19.
Under a heading in the minutes of “Reservoir,” there is only a cryptic, and singular, note on the water storage projects. It says “Mr. Kerrigan said Dale Rea is preparing land filings on the reservoir.”
A district court judge would eventually make the rights official on Nov. 5, 1971, giving the conditional water rights their adjudication date. The process to adjudicate water rights often took years because the water court slowly reviewed large bundles of applications.
The Castle Creek Reservoir, decreed in Civil Action 5884, was given Structure No. 589 and Priority No. 805. The Maroon Creek Reservoir, also decreed in CA 5884, was given Structure No. 590 and Priority No. 806.
Civil Action 5884 is a 242-page decree that earmarked priority numbers for a long list of other potential local reservoirs, including Ashcroft Reservoir, Pabst Reservoir, Snowmass Reservoir, and the Paepcke Forebay Reservoir on the main stem of the Roaring Fork River.
The rights to the Castle and Maroon reservoirs are the only significant conditional storage water rights decreed in CA 5884, in what could be considered “the class of 1971,” that are still being maintained today.
Rea, the consulting engineer for the city of Aspen, was from Littleton and he had spent 12 years with U.S. Bureau of Reclamation, mostly in Denver, before going out on his own to design and develop water systems for a number of growing Colorado cities.
In 1956 he was contacted by the city, which had just purchased a large portfolio of senior water rights on Castle and Maroon creeks from the Holy Cross Electric Association.
The rights were originally used to produce hydropower in the 1890s, with the water diverted from the two creeks and sent down wooden flumes to a knob of land on the hillside between the two creeks.

The 1956 water plan
By the mid-1950s, the city was also in the process of acquiring the assets of the Aspen Water Co., a private water company that had been struggling for years to provide the citizens of Aspen with a reliably clean supply of water.
Rea submitted a water plan on Aug. 17, 1956, that was designed to provide for the city’s water needs from 1957 to 1977.
“The report included requirements, supply, treatment, distribution, operation, maintenance, finance and revenue of a complete system,” the Aspen Times reported about Rea’s 1956 water plan. “It incorporates an estimated 1,700 to 3,500 permanent residents with provisions for transient populations of 5,000.”
Rea recommended that the city build a new water system using its senior water rights on Castle and Maroon creeks.
Rea’s 1956 report made no mention, though, of dams being necessary on either upper Castle and Maroon creeks, even up to 1977, to supply the city with adequate water.
Instead, Rea said there was “sufficient water” available from Castle Creek “without storage.”
“The city’s best water right is out of Castle Creek with priority No. 136a in the water district for 60 cubic feet per second (for) irrigation and domestic supply,” Rea wrote. “Therefore the city would have no problem on Castle Creek with respect to water rights or adequately [sic] of supply, as low flow records on Castle Creek indicate that the supply is more than double the future requirements of the city.”
Under the heading of “surface supply,” Rea declared, “Surface water supply in Aspen should be no problem, as Pitkin County probably has a greater run-off per acre than any county in Colorado.”
And under the heading of “reliability,” he noted that “in some communities severe drought conditions and underground pumping of individual development will gradually diminish the surface flow to a point where it is dangerous for a city to rely strictly on surface water flow. Fortunately this is not the case in Aspen, as the large drainage basin of each of the streams under study are sufficient to yield a continuous flow at all times.”

Urgent water need
On March 5, 1959, Rea attended a special joint meeting of the Aspen City Council and the city’s new “utility advisory board,” which was to oversee the city’s new water and electric utility departments.
According to the Aspen Times the main agenda item was “how to get a safe water system in the quickest possible time in the most efficient way.”
Rea, the Times wrote, “told the assembled officials that the only logical source of water at the present time was Castle Creek. This is the only source on which the city owns adequate water rights.
“Following Rea’s report and a general discussion it was decided to take his recommendations drawing up the plans necessary to develop a state-approved system using Castle Creek as a source of water,” the Times reported.
Today, Castle Creek remains the city’s primary source of water.
On Oct. 12, 1959, Rea attended another meeting in Aspen, as city officials were wavering on their earlier decision to build their new system based on a supply of water from Castle Creek, and instead were thinking of using water from Hunter Creek.
“At Monday’s meeting, and at several previous meetings, engineer Dale Rea informed officials that additional water rights would be needed before Hunter Creek could be considered,” the Times reported. “The city already owns more than enough rights on Castle Creek to enable it to use that stream as the primary source for its system.”
The city owned, and still does own, two large water rights on Castle Creek, one dating from 1885 for 60 cfs and an 1889 right to 100 cfs. And it owns a right from 1892 for 65 cfs from Maroon Creek. On Colorado’s Western Slope, these are large, and senior, water rights and make the city the dominant rights holder on the creeks, and especially so on Castle Creek.

The water council
In 1963 Harald Pabst ran for mayor of Aspen on top of a “clean sweep” ticket, and Aspen’s water rights and water delivery system was a campaign issue.
Pabst was the grandson of the founder of Pabst Brewery. He came to the Aspen area in the 1950s and bought a large swath of ranch land in the lower Snowmass and Capitol Creek valleys.
According to the Times, Pabst was “well known to Aspenites for his duties as administrative vice president of the Aspen Institute and director of the Aspen Skiing Corp.,” which was then a public company.
Each of the council candidates in 1963 laid out their campaign platforms in a front-page feature in the Times in October, and each of them addressed water.
In his candidate statement, Pabst said, “although the subject of Aspen’s water supply has probably received more attention than any other problem, there is still much dissatisfaction and uncertainty expressed by Aspenites.
“We feel that a thorough, factual re-evaluation of the water problem should be made, based on an inventory and analysis (volume, purity, etc.) of existing adjudicated water rights and related existing structures, cost of required improvements and new facilities, as well as operating costs.”
The balance of the 1963 “clean sweep” ticket in Aspen included Werner Kuster, the owner of the Red Onion bar and restaurant, Dr. Robert Barnard, who would go on to serve as Aspen mayor, Bill McEachern, and Dave Stapleton.

Risk of losing rights
Robert “Bugsy” Barnard, in his statement printed in the Times, said it was “difficult to understand how a city such as Aspen can be surrounded by four rivers and still be plagued with an insufficient water supply that requires rationing during the summer months and is frequently found to be contaminated by disease-producing micro-organisms. And all this in the face of extremely high water costs to the consumer.
“A further difficulty in the water situation lies in the fact that by ceasing to use any of the city’s surface water rights in the Roaring Fork River, Castle Creek or Maroon Creek, Aspen faces the serious risk of losing these water rights through non-use,” Barnard wrote, citing a concern that still exists in City Hall today.
The clean-sweep ticket did just that on Nov. 5, 1963, when 411 votes were cast, a record turnout for Aspen at the time. And so a new Aspen City Council was soon seated, and it had water on its agenda.

Updated water plan
In March 1964 the water-focused city council directed Rea “to investigate and draw up plans and specifications for a long range water plan,” according to the Times, and the next month Rea signed a new contract with the city to develop the plan.
In December 1964, nearly six years after his first water plan for the city, Rea submitted a “water supply and development feasibility study,” and this time he declared that water storage would be necessary to meet future needs.
“The ultimate density of the entire Aspen valley from the lower end of the airport to the originally proposed Aspen Dam on the Roaring Fork is 65,980 people,” Rea wrote. “The water use for this population is estimated at 28 million gallons per day; to supply this water it will be necessary to construct dams on both Castle Creek and Maroon Creek and possibly Hunter Creek.”
Today, the peak-population day of about 35,000 people in the city’s water service area typically comes on July 4, and the city’s water treatment plant has a current capacity of 20 million gallons per day.
“It is estimated that this population could be reached in about 40 to 50 years which is not too long to plan a water system,” Rea added. “At that time, the total estimated flows of Castle Creek and Maroon Creek will be needed to supply Aspen’s need of about 28 million gallons per day.”
Rea then recommended to the council “that dam and reservoir sites be selected on Castle Creek and Maroon Creek and filings for their use be made with the state engineer.”
“In order to expand the supply in these two creeks, large storage reservoirs can be constructed, one on each creek,” Rea also wrote.
These are apparently the first calls in a city plan for reservoirs on Castle and Maroon Creek, and they appear to be based on an overly large population forecast.
Even Rea acknowledged in his 1964 report that his population projection was “on the optimistic side and ‘good times’ will have to remain if the projection is to be realized.”
Rea also wrote that one of the purposes of the report was to “project the growth of the community to require the full development of the city’s water rights.”
And he recommended, “any surplus water rights from the proposed development of these sites be sold to prospective downstream users,” suggesting there would, in fact, be “surplus water” from the reservoirs.
Rae’s 1964 report, and its recommendations to build reservoirs, resonated with the city council led by Mayor Pabst.
Rea would later testify that his report to the council “resulted in the making of claims of the city to the state engineer for reservoirs … to supply the city of Aspen in the foreseeable future.”

Council takes the plunge
On July 22, 1965, Rea sent a letter to city administrator Kerrigan laying out a scope of work to begin investigating aspects of Aspen’s long-range water supply system, including the two reservoirs.
The letter laid out plans for locating a “large storage reservoir” on both Castle and Maroon creeks.
“Field work for preliminary filing could be done before snow falls if authorized at once,” Rea wrote, and noted, “This project has been discussed with the state engineer and it meets with his approval.”
And Rea wrote two of the more intriguing sentences in the available historical record about the value of filing for the storage rights.
“We believe these filings will greatly enhance your water rights,” Rea told Aspen’s Kerrigan. “Further, in the case of Castle Creek, the need may not be too far in the future.”
The city council of 1965 would affirmatively vote on their intent to file for water rights on the dam sites at a council meeting on Aug. 2, 1965.
On Sept. 1 Rea began working in the field to survey the locations for the two reservoirs. And it appears from the historic public record that it was Rea, and Rea alone, who determined where the two potential dams should be built and how big they should be.
On Dec. 6, with Rea’s work in the field complete, the city council was informed that the required maps for the upcoming water rights filing would be signed by Mayor Pabst.
The minutes of the meeting state: “Filings on Maroon and Castle Creek: Mr. Kerrigan referred to filings on Maroon and Castle Creek – maps to be signed by mayor and city clerk and sent to Dale Rea to be filed with state engineer.”
And sometime before Dec. 29, when the maps for the two reservoirs were were duly filed with the state engineer’s office, both Rea and Mayor Pabst signed the maps.
The 1965 map for the Maroon Creek Reservoir shows a dam across Maroon Creek, just below the confluence of East and West Maroon creeks. The note on the map says the height of the planned dam is 155 feet, the resulting reservoir’s capacity is 4,567 acre feet and the estimated cost of the project was $770,000.
The map for the Castle Creek Reservoir shows a dam across Castle Creek, between Fall and Sandy creeks. The notes on the map say the height of the dam is 170 feet, the capacity 9,062 acre-feet and the cost is $790,000.

Dam the Fork?
Before Aspen filed for the maps describing the scope and scale of the dams and reservoirs on Castle and Maroon, it also investigated the idea of building a large dam across the main stem of the Roaring Fork River.
In March 1963, the city council directed staff to continue investigating the feasibility of building a dam on the main stem of the Roaring Fork River, at a deep and narrow part of the river between the airport and Shale Bluffs. The location, notably, was below the confluences of both Castle and Maroon creeks.
The council discussion was labeled in the minutes from March 18, 1963, as “feasibility – water rights use.”
“Discussed – water rights – and council directed that the city administrator continue the investigation of the feasibility of using the water rights owned by the city of Aspen from Hunter Creek, Maroon Creek, Castle Creek, the Roaring Fork River and other tributary sources, at a point on the Roaring Fork River … ,” the minutes state.
And in September 1963, the council took another step toward a potential dam on the Roaring Fork.
The minutes of a regular council meeting, under the heading, “Water – utilization program,” state, “[City] Attorney Stewart and council discussed plans for definite utilization of water and water rights. Point of diversion this side of Shale Bluffs. Dam for power, irrigation, flood control and recreation. A feasibility report is to be considered this fall, and the engineer should establish 2 to 3 damsites, and prepare plans.”
The council then voted unanimously on a motion to “conduct investigation to determine the places of potential damsites on the mainstem of the Roaring Fork River below Aspen” and to file a map and claim statement with the state engineer.
Three years later, in April 1966, the Colorado River District, not the city of Aspen, filed a map with the state that included a 150-foot-tall dam across the Fork.
The potential dam was now part of the Snowmass Project, and the resulting reservoir, which could hold 4,760 acre-feet of water, was called the Paepcke Forebay.
A pipeline, called the Gerbaz Conduit, was to run from the Paepcke Forebay to Watson Divide and Snowmass Creek. Water was to then to be sent down the creek and collected again in the Pabst Reservoir, which was to hold 73,645 acre-feet of water behind a 290-foot dam on lower Snowmass Creek. By comparison, Ruedi Reservoir holds about 102,000 acre-feet of water.
Water from the Pabst Reservoir was then to run down the last part of the creek to a hydropower plant at the confluence with the Roaring Fork, in what is now Old Snowmass.
The conditional water rights for the Snowmass Project would go on to be cancelled by a water court judge for lack of diligence in 1979, mainly because the Paepcke Forebay on the Roaring Fork would have flooded the site of the wastewater treatment plant operated by the Aspen Consolidated Sanitation District, and the project stalled.
So as it turned out, the city of Aspen’s efforts to build a dam across the main stem of the Roaring Fork would not result in concrete ever being poured. And perhaps the councils of the early 1960s sensed such a plan might never come to fruition.
Next up in the series: The city of Aspen defends the conditional water rights in court as its consulting engineer calls for more study of the dams and reservoirs.
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 Monday, Dec. 26, 2016.