Our goals are to ensure dams are never built in either of these two iconic valleys and to secure protections for both creeks.  Here’s a quick summary of the issue:

  • In 1965 aspen projected future growth of up to 66,000 people and filed for conditional water rights for two separate reservoirs on Castle and Maroon Creeks to meet that demand.
  • To keep these rights, Aspen must submit a diligence filing every six years. On October 10th, 2016 the city council unanimously passed a resolution stating in part that the city will “develop all necessary water rights, including but not limited to, Maroon Creek Reservoir and Castle Creek Reservoir,” and subsequently filed for diligence on October 31st.
  • The Maroon Creek Dam would be located just below the confluence of East and West Maroon Creeks, flooding 85 acres behind a 155-foot-tall dam. The Castle Creek Reservoir would be located downstream of the American Lake trailhead, flooding 120 acres behind a 170-foot-tall dam.
  • Both dams would inundate portions of the Maroon Bells-Snowmass Wilderness and cause significant environmental damage: severing the streams in two, flooding important riparian habitat, and reducing the ecologically critical spring peak flows.
  • Conditional water rights provide no legal protection against another party who wishes to build a dam or diversion.  The best way to protect the creeks is with a Wild and Scenic River Designation or by increasing the minimum in-stream flows.
  • While the city is not proposing to build these dams in the immediate future, all council members supported preserving this option for the long term.

The proposed Maroon Creek dam site.

The Castle Creek Reservoir would store 9,062 acre-feet of water behind a 170-foot-tall dam.

Public’s response: don’t keep the water rights

Due in large part to our advocacy, aspen held a stakeholder meeting, a public open house, and a two-week public comment period. While we appreciate the city’s good faith effort to include the public in its deliberative process, city staff focused the discussion on population and climate change scenarios, and spent little time on the impact of the reservoirs. Both aspen Public radio and Aspen Daily News ran stories about the “limited time for questions” at the open house.
WW submitted a detailed comment letter outlining our objections to aspen retaining water rights and offering to collaborate on seeking new protections for the creeks.

Over 50 citizens also wrote letters, all echoing our concerns and asking the city to abandon these two dams.

The city council met three times to discuss water rights, but those meetings focused almost exclusively on the impact of population growth and climate change to aspen’s future water supply. They were silent on the ecological impacts of the dams, the regulatory obstacles, financial costs and dubious assertion that these rights actually protect the streams. Over a dozen concerned citizens spoke, unanimously asking the city to abandon their water rights. Despite this outcry, the city is moving ahead. all five council members justified their vote on the basis that we might need to store water in the future despite their recent study concluding just the opposite.

No demonstrated need for water in the future

It’s worth taking a closer look at the council’s claims. The city’s argument begins with two reasonable assumptions: population growth equals increased demand and climate change equals reduced supply. The city has studied future water supply and demand but has never connected this to a need to build reservoirs or if so, whether these two reservoirs are in the best locations to meet that need.

The best and most recent in-formation on future water supply and needs is in the city’s 2016 Water supply availability study that concluded, “the city can always provide sufficient potable and raw water supplies.2” This study models projected water demand under different population growth scenarios for 50 years into the future and concludes that under the highest growth projections of 1.8%, our indoor water use would increase from a maximum daily use of 3.4 cubic feet per second (cfs) to 8.2 cfs. additionally, outdoor water use in the summer could double, but it’s very unlikely that our community is prepared to justify building these reservoirs to water lawns!

Ecological Impacts of Dams

Dams sever streams in two. A dam obstructs fish and other aquatic organisms from moving freely in a river. Land ani-mals also use rivers as corridors and a dam significantly reduces that ability. additionally, shady, wet river corridors have been identified as crucial habitat for animals adapting to a warmer, drier world.

Dams flood important wetlands and riparian habitat. Over 80% of animals in colorado utilize rivers and adjacent riparian areas. combined, these two dams would flood over 200 acres of largely pristine river corridor and wildlife habitat. But the impact would be much more than 200 acres given the associated infrastructure, road building, and general industrialization of the landscape.

Dams capture the ecologically critical spring peak flows. Each spring the flushing flows from snowmelt re-arrange stream sediments and replenish wetlands. This creates and sustains the structure and function of the river-corridor habitat. The significant ecological changes below other dams provide a clear record of how damaging reducing peak flows can be to ecosystems.

The Wilderness Workshop is the conservation watchdog of nearly 3 million acres of public lands in western Colorado.

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