C.R.E. 408 Communication; Case Nos. 16CW3128 & 16CW3129
TO:
FROM:
DATE:

The City of Aspen
Western Resource Advocates & Wilderness Workshop
4/27/2017

SUBJ:

Potential Conservation Alternatives to Dams on Maroon
& Castle Creeks

______________________________________________________________________________
During our March 21, 2017 meeting, City representatives asked the opposers, and in particular the
conservation groups, to explore alternatives to the proposed dams that could help ensure that the
City of Aspen is able to meet its future water needs. Accordingly, Western Resource Advocates
and Wilderness Workshop offer the following recommendations of potential alternatives.1 We
look forward to discussing these alternative solutions with you, and we welcome the opportunity
to develop and add detail to these suggestions in partnership with the City. We believe that, if
implemented, these alternatives would not only position the City of Aspen to provide water for its
citizens, but also to be a recognized leader in Colorado on innovative water management policies.
Water Efficiency
Water conservation is often the cheapest, fastest, and least-controversial way to gain a “new” water
supply.2 While conservation does not increase the total amount of water that a provider can utilize,
water that is saved through conservation can be put to other uses, in effect, stretching existing
supplies. Conserved water can be used by a utility to fulfill new customer demands, increase supply
reliability, or provide additional flows to the environment. To date, the City of Aspen has
developed reasonable water efficiency measures, including the 2015 Aspen Water Efficiency Plan,
the 2015 Regional Water Efficiency Plan for the Roaring Fork Watershed, and the upcoming 2017
Water Efficient Landscaping Standards.
The City of Aspen is on a path towards employing strong and effective water efficiency policies.
Yet, we believe that the City has room for additional passive and active conservation gains. Passive
conservation is the reduction in water demand due to permanent savings related to regulatory and
market influences (e.g., higher efficiency toilets replacing older models). Active conservation, on
the other hand, is the reduction in water demand due to programs implemented by the City (e.g.,
1

This memorandum strives to provide as much detail as is possible at this time. However, without additional data
providing an accurate picture of how the City of Aspen’s customers use water, as well as additional empirical evidence
that can be used to measure the effectiveness of the City’s water conservation efforts, we cannot currently provide
more specific information regarding a reasonably expected amount of total water savings that the City could expect
to achieve. We welcome the City’s assistance in improving our analysis.
2
Kenney, D.S., M. Mazzone, and J. Bedingfield. 2010. Relative costs of new water supply options for Front Range
cities: Phase I (draft). Boulder, CO: University of Colorado Natural Resources Law Center, Western Water Policy
Program.

 C.R.E. 408 Communication; Case Nos. 16CW3128 & 16CW3129

water waste and xeriscape ordinances). Together, these cost-effective measures can provide the
City with large savings in annual water use.
In the 2015 Aspen Water Efficiency Plan, the City ran three treated water forecasts, going out to
2035: (1) a baseline model, with no conservation measures; (2) a model incorporating passive
conservation; and (3) a model incorporating the active conservation measures employed by
Aspen.3 These models demonstrate that the City can take proactive steps to conserve water which
could serve as part of an alternative to building dams. For example, the City’s conservationoriented rates and updated landscape regulations, among other measures, are likely to greatly
reduce water demands. Accordingly, we expect Aspen’s water demands to more closely follow the
third forecast that includes both passive conservation and necessary active conservation actions.
Implementing conservation measures consistent with this forecast will be relatively inexpensive
and better for the environment. The third forecast is also the most likely measure of Aspen’s future
water demands because it best matches the values of a forward-thinking community like Aspen.
In the 2015 Aspen Water Efficiency Plan, Aspen expressed its concerns with peak water demands
because of its modest ability to store water. Reducing outdoor water use directly alleviates
problems with peak water demand. Recent studies demonstrate that substantive savings can be
achieved. The Southern Nevada Water Authority, through a turf to xeriscape conversion program,
saved 96,000 gallons per year, while the San Diego County Water Authority saved 1.7 acre-feet
per year through a landscape audit and retrofit grant program.4 Therefore, we recommend that the
City of Aspen place a greater emphasis on both temporary and permanent reductions in outdoor
water use, including transforming existing landscapes to be more water-wise (or use non-potable
water), as well as making sure that all new development is water smart by placing stronger
regulations on new construction, to supplement the Water Efficient Landscaping Standards the
City plans to release this summer. By addressing reductions in outdoor use, the City can support
its other water efficiency efforts and ensure that the city’s water supply is more than adequate in
the future. Western Resource Advocates and Wilderness Workshop would like to work with the
City to further analyze ways to achieve greater reductions in outdoor water use.
Reuse
Implementing a reuse program can be an effective way to meet water needs. When a community
recycles its legally reusable supplies5, additional demands are met with the same initial volume of
water. To help quantify Aspen’s reuse potential, we would need to better understand the City’s
current and planned future water rights portfolio. Our preliminary research suggests that the
potential for reusing the City’s existing supplies has some limits. However the City’s proposed
3

Element Water Consulting and Water DM, Municipal Water Efficiency Plan: City of Aspen, Colorado 32 (2015).
Western Resource Advocates, The Case for Conservation: Landscape Irrigation Efficiency and Conversion at 2,
available at http://westernresourceadvocates.org/healthy-rivers/water-conservation-efficiency/.
5
Under Colorado state law, legally reusable water sources include: (1) transbasin diversions; (2) transferred
consumptive use; (3) nontributary groundwater; and (4) other decreed reusable supplies. See, e.g., COLORADO’S
WATER PLAN at 6-75 (2015).
4

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 C.R.E. 408 Communication; Case Nos. 16CW3128 & 16CW3129

reclaimed water project indicates that it is possible to incorporate significant reuse into its
portfolio. This project, in which approximately 540 acre-feet6 of treated return flows from the City
would be used for irrigation and snowmaking, would be an important step in stretching existing
supplies and leaving water in streams.
Recent and ongoing regulatory and technical advances have made reuse systems cost competitive
as compared to other potential new water supply options. Further, there is a growing interest in
potable reuse, in which water can be reused anytime, anywhere, for any purpose. Potable reuse has
many benefits to non-potable reuse, including increased yield from subsequent reuse of indoor
return flows, which can effectively double the demand that can be met with the same volume of
water. In 2010, the City of Aurora implemented their indirect potable reuse Prairie Waters
Program, which currently has the capacity to provide 10,000 acre-feet (planned to grow to a total
of 50,000 acre-feet) to improve that community’s water supply reliability and drought resistance.
WaterReuse Colorado, the Colorado Department of Public Health and Environment, and numerous
water utilities are working collaboratively to develop a regulatory framework for direct potable
reuse, funded in large part by the Colorado Water Conservation Board Water Supply Account
Funding. Finally, SWSI 2010 identified up to 61,000 acre-feet of future water supply from planned
reuse projects; Aspen’s water supply was included in the analysis. We would welcome the
opportunity to discuss potential potable reuse opportunities with the City as well as how recycling
can optimize any supplies, existing and future, from alternative and traditional agricultural water
transfers, as discussed below.
Alternative Agricultural Transfers
The City of Aspen could potentially increase its pool of reusable water through the acquisition of
more water using alternative transfer mechanisms (ATMs).7 The consumptive use portion of any
agricultural water rights that the city obtains through ATMs would likely be reusable. Recent
reports from the Colorado Division of Water Resources show substantial decreed agricultural
water rights above and below Aspen in the Roaring Fork Valley. The City could obtain some of
them, on either a temporary or permanent basis, through the use of ATMs, to further stabilize the
city’s water supply in times of high demand. This irrigated acreage in and just downstream of
Aspen that may provide fruitful opportunities for such transfers.
ATMs are already being used to meet water needs in Colorado and throughout the West. The
Lower Arkansas Valley Super Ditch Company allows certain irrigators to lease agricultural water
to other uses, while the Metropolitan Water District of Southern California & Palo Verde Irrigation
District are parties to a decades-long agreement enabling voluntary water transfers to meet urban

Statewide Water Supply Initiative (SWSI) 2010 Portfolio Tool “City of Aspen - Golf course reuse/West Aspen
Reclaimed Project” yield.
7
The Colorado Water Conservation Board broadly defines ATMs as “creative alternatives to the traditional purchase
and transfer of agricultural water.” The Board also provides examples and describes grant opportunities on its website:
http://cwcb.state.co.us/loansgrants/alternative-agricultural-water-transfer-methods-grants/pages/main.aspx.
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 C.R.E. 408 Communication; Case Nos. 16CW3128 & 16CW3129

water demands. A 2016 report notes that generally, the costs of obtaining water through an ATM
are not dissimilar from costs of acquiring water through more traditional acquisition processes.8
Conclusion
We believe that the City can build upon its past work on water efficiency and reuse to provide
water security to its citizens, without having to consider building dams in Maroon and Castle
Creeks. Our team of water policy specialists, engineers, and attorneys, working in tandem with
the City’s career water and utility staff, can work together to safeguard the City of Aspen’s water
supply without damaging the iconic valleys above Aspen. The City has a long history of leadership
advancing innovative solutions to complex environmental challenges. We believe this issue
provides an excellent opportunity to continue that legacy. We look forward to working with the
City of Aspen to secure the City’s current and future water needs in a manner that is consistent
with the values of the people of Aspen.

8

Alternative Water Transfers in Colorado: A Review of Alternative Transfer Mechanisms for Front Range
Municipalities, ENVIRONMENTAL DEFENSE FUND 7 (2016), https://www.edf.org/sites/default/files/alternative-watertransfers-colorado.pdf.

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