WILD HORSE FAQS

Q. Why is there a need for Wild Horse Reservoir?
A. Aurora Water has one of the most comprehensive and effective water conservation and reuse programs in the country. However, water conservation and reuse alone cannot maintain Aurora Water’s emergency water reserves. Wild Horse Reservoir would provide the critical water storage—like a savings account—that Aurora Water requires to ensure reliable water delivery for community needs and maintain accessible emergency water reserves during severe and prolonged droughts or system emergencies, such as wildfires, pipeline breaks, or system outages.

Q. Is Wild Horse Reservoir needed to support future growth in Aurora?
A. The purpose of the Wild Horse Reservoir project is to enhance the resilience of Aurora Water’s systems. Through comprehensive and effective water conservation and reuse efforts, Aurora Water can meet projected community water needs in 2075 without additional storage but would be unable to maintain its emergency water reserves. Wild Horse Reservoir would enable Aurora Water to provide a reliable water supply while retaining its required emergency water reserves.

Q. Why do cities keep putting in new reservoirs?
A. Droughts greatly challenge Colorado. The Wild Horse Reservoir is a critical component of the infrastructure needed to ensure sustainable water deliveries to meet future demands and to enhance resilience during droughts or emergencies. Having more reservoirs also allows for better management of existing water rights by allowing flexibility during maintenance, providing consistent levels needed for environmental management and recreational use, and greater drought protection.

Q. Would Wild Horse Reservoir require any new water rights? What does “no new water rights” actually mean?
A. Water stored in the new reservoir would be supplied by Aurora Water’s existing Arkansas and Colorado River water rights so no new water rights or decrees would be required for the project.

Under Colorado law, a water right is the right to divert, store, and use water. The proposed reservoir would give Aurora more flexibility and improve resilience throughout our water system. Given our current storage capacity and locations, not all water rights can be stored and used throughout the year.

Q. How would Wild Horse Reservoir be filled?
A. Wild Horse Reservoir would be off channel, meaning no river or stream would flow into or out of it. Water would be supplied into the reservoir through a new inlet pipeline connected to the existing Otero pipeline. A new outlet pipeline would be constructed to transport water from Wild Horse Reservoir to Spinney Mountain Reservoir as needed. No new water rights or decrees would be needed to fill the reservoir.

Q. How long would it take to fill the reservoir?
A. It is estimated that it would take approximately four years to fill the reservoir under average water supply conditions.

Q. How would the water in Wild Horse Reservoir get to Aurora?
A. Water stored in Wild Horse Reservoir would be released into Spinney Mountain Reservoir via a new outlet pipeline that would connect to Wild Horse Reservoir. Water from Spinney Mountain Reservoir would then be released and flow down the South Platte River through several existing reservoirs (including Eleven Mile Reservoir) before reaching Aurora.

Q. How would Wild Horse Reservoir compare to other reservoirs?
A. Wild Horse Reservoir would likely be the 23rd largest reservoir in Colorado when ranked by storage volume. Wild Horse Reservoir would be Aurora Water’s largest reservoir and would store approximately triple the water volume held by Aurora Reservoir. The table below compares the proposed size, storage, and depth of Wild Horse Reservoir to other Colorado reservoirs.

Dillon Aurora Spinney Antero Wild Horse
Acres of Land Footprint 3,233 735 2,402 2,500 ~1,700
Acre-feet of Water Storage* 257,304 31,604 53,651 20,000 ~90,000
Max Depth in ft 177 101 60 20 ~150

Note: *An acre-foot (af) is 325,851 gallons and is defined as the amount of water it takes to cover an acre of land with one foot of water. One acre is about the size of a football field and can serve three households in Aurora.

Graphic showing an acre foot of water overlaid on a football field.

Q. Why is it called Wild Horse Reservoir?
A. The name “Wild Horse” originates from the geological formation that forms the “bowl” of the reservoir, known as “Wild Horse Canyon,” where the main dam is anticipated to be located.

Q. Who is doing the permitting?
A. The Bureau of Land Management (BLM), as the lead federal agency, is managing the federal National Environmental Policy Act (NEPA) permitting process and will prepare an Environmental Impact Statement (EIS) for the project. Additional state and local permits and authorizations will be coordinated with the appropriate federal, state, and local government agencies, including Park County.

Q. What are the alternatives to Wild Horse Reservoir that will be evaluated as part of the NEPA process?
A. Under NEPA, BLM is required to analyze a “reasonable range” of alternatives to Wild Horse Reservoir, which is Aurora Water’s proposed action. The NEPA analysis process helps BLM ensure there is informed decision-making. BLM will consider different ways (i.e., alternatives to the proposed action) to achieve the purpose and need of the project while considering potential environmental and social impacts. In addition to the Proposed Action, BLM currently plans to analyze a No Action Alternative—that is, what Aurora Water would do if BLM does not authorize Wild Horse Reservoir—and three other alternatives, including:

  • Wild Horse South Reservoir Alternative
  • Small Wild Horse Reservoir plus Denver Basin Aquifer Storage and Recovery (ASR) Alternative
  • Spinney Mountain Reservoir Enlargement Alternative

This range of alternatives is preliminary and subject to change as BLM considers public input throughout the NEPA process. See a map of the potential alternatives.

Q. Why did Aurora Water choose Park County?
A. The proposed Wild Horse Reservoir site in Park County was selected for its proximity to the existing Otero Conveyance System, which currently transports approximately half of Aurora’s water supply from the mountains to Spinney Mountain Reservoir. In addition, the location has favorable topography and environmental conditions, including:

  • The site is off channel and would not dam a stream or river
  • Higher elevation reservoirs have less evaporation
  • Based on studies completed by Aurora Water to date, constructing a reservoir at this location would have minimal environmental impacts**
  • Aurora Water’s initial studies have not identified any jurisdictional wetlands or endangered species that would be impacted by Wild Horse Reservoir**

Note: **BLM will complete its own independent study of potential environmental impacts as part of the NEPA process.

Q. Has Park County been involved in the planning for Wild Horse Reservoir?
A. Yes, Aurora Water has met with Park County officials before evaluating the location and pursuing the Wild Horse Reservoir project. Aurora Water’s staff has established a strong and collaborative working relationship with Park County and will continue to coordinate with Park County as the project continues.

Q. What recreation would be offered at Wild Horse Reservoir?
A. Providing recreational opportunities in Park County at the proposed reservoir site is important to Aurora Water. Aurora Water is looking at what recreational uses may be most appropriate and complementary to those offered at other regional reservoirs. Aurora Water is listening to community feedback and is coordinating with the Bureau of Land Management (BLM), Park County, and Colorado Parks and Wildlife (CPW) to develop a draft recreation proposal for Wild Horse Reservoir. Draft recommendations would be presented for public input within the next 12-24 months in parallel with other permitting processes, including public scoping during the NEPA process.

Q. Would there be any benefits to Hartsel and Park County from the project?
A. Yes, local businesses and new businesses would be asked to support construction by providing goods and services. It is anticipated that the proposed reservoir would draw more visitors to the area, lending further support to local businesses in the future.

Q. How would the construction of Wild Horse Reservoir impact those living and working in the area?
A. If BLM authorizes the project, Aurora Water is committed to working closely with Park County, local residents, and businesses to minimize and address potential construction impacts. As with any large infrastructure project, Aurora Water would anticipate increased truck and vehicle traffic, noise, dust, and some road detours and closures. These impacts would be minimized to the greatest extent possible. As part of BLM’s review of the project, BLM will be considering how potential environmental and social impacts can be avoided, minimized, and/or mitigated under its NEPA analysis and is coordinating with Aurora Water on such considerations.

Q. Would Wild Horse Reservoir impact local groundwater?
A. Aurora Water does not own groundwater rights in Park County, and Wild Horse Reservoir is not expected to affect local groundwater. Potential groundwater impacts will be studied and disclosed as part of the NEPA process.

Q. What work is Aurora Water doing in Park County this summer?
A. With landowner permission, Aurora Water’s contractors are conducting natural resource and cultural resource surveys this summer. Those surveys are focused on areas that have not been previously assessed. Aurora Water also had crews in the area to collect geotechnical data to help further assess construction feasibility and inform the design of the project. As part of this work, large equipment, such as drill rigs, were visible.

Additionally, in August, standard maintenance work is anticipated to begin on the Otero pipeline in Park County. That work is not related to the Wild Horse Reservoir project.

Q. Where would County Road 53 be realigned? When would that start?
A. If BLM authorizes this project, a portion of County Road 53 would need to be realigned to the east side of the proposed Wild Horse Reservoir site. The date of such work would be identified following the minimum two-year timeframe for BLM to complete its NEPA analysis and would only occur if BLM authorizes the project. Aurora Water would work closely with Park County regarding the timing of the road realignment and communicate that work to area residents in advance.

In addition, Aurora Water entered into a Memorandum of Understanding (MOU) with Park County that provided the county with $250,000 to help repair roads damaged by weather conditions last winter.

Q. Would Spinney Mountain Reservoir’s water levels be impacted by Wild Horse Reservoir?
A. If Wild Horse Reservoir is authorized by BLM and constructed, Spinney Mountain Reservoir would be used primarily to store water from the South Platte River and to maintain water in storage for recreational purposes and for emergencies. Spinney Mountain Reservoir would continue to help Aurora Water manage its voluntary flow program for the upper South Platte River known as the “Dream Stream.” Some variation in Spinney Mountain Reservoir levels occur now and would continue to be expected based on water supply conditions, such as drought, runoff, and seasonal changes.

Q. Would the “Dream Stream” be impacted by Wild Horse Reservoir?
A. Aurora Water would continue to honor all stream flow protocols. Aurora Water’s modeling for the project shows Wild Horse Reservoir would have minimal impacts on streamflow in the “Dream Stream.” BLM will conduct its own evaluation of potential streamflow impacts from the project and report the results of its analysis in the Draft EIS it will prepare.

Q. Would Wild Horse Reservoir negatively impact other rivers and streamflow?
A. Aurora Water would continue to honor all stream flow protocols and water rights. Wild Horse Reservoir would use Aurora Water’s existing Colorado and Arkansas River water rights so no new water rights or decrees would be sought to fill the reservoir. The reservoir would be off channel, meaning that it would not dam any rivers or streams. BLM will conduct an evaluation of potential streamflow impacts from the project and report the results of its analysis in the Draft EIS it will prepare.

Q. What is the timeline for completion? When would Aurora Water break ground, and when would the reservoir open?
A. The project is currently in the pre-permitting phase. The formal NEPA process would last a minimum of two years from the date that the Bureau of Land Management (BLM) publishes its Notice of Intent (NOI) to prepare an EIS for the project. Aurora’s goal is to begin construction around 2030, pending receipt of all necessary permits, authorizations, and approvals. To stay up to date with the latest information, please sign up for Aurora Water’s Wild Horse Reservoir project eNewsletter.

Q. Who would be doing the construction?
A. Aurora Water has selected Colorado-based Flatiron and joint-venture partners Dragados USA and Sukut Construction (FDS JV) to provide Construction Manager/General Contractor (CM/GC) services for the proposed Wild Horse Reservoir. FDS JV would hire subcontractors as needed to complete the construction.

Q. How many jobs would this project create?
A. Approximately 600 temporary jobs at the peak of construction.

Q. Where would all those workers live/stay?
A. To the extent practical, FDS JV would hire as many local employees as possible who do not require local housing. Additional construction staffing options would be explored, including bussing workers in from Woodland Park and/or Bailey, using RVs, and/or constructing temporary workforce housing on Aurora-owned property.

Q. What are Aurora Water’s conservation and reuse programs?
A. Aurora Water has one of the most comprehensive and effective water conservation programs in the country. Even though Aurora’s population has grown, water use per person has actually decreased by 36% since 2000.

  • Aurora was the first city in the state to limit non-functional turf grass (including common areas, curbside, and curbside for front yards).
  • Aurora Water launched the first water reuse program in the state, and it remains the largest reuse system today.
    • Aurora Water was an early adopter of using reclaimed water for irrigating parks and golf courses.
    • Aurora Water’s Prairie Waters System was the first of its kind and remains the largest indirect potable reuse (IPR) system in Colorado, delivering up to 10 million gallons of water per day to Aurora Water’s water system. The Prairie Waters System is an innovative potable reuse system that uses a sustainable water source by recapturing river water as a cornerstone of its water supply.
    • Aurora Water will likely expand the Prairie Waters System before completing Wild Horse Reservoir.
    • Approximately 95% of the city’s water can be reused over-and-over again.
    • Aurora Water is evaluating the use of direct potable reuse (DPR) (a method for recycling water).

Q. How much water does Aurora typically use annually?
A. The city uses approximately 55,000-58,000 acre-feet (or between 18-19 billion gallons) of water per year to serve over 400,000 people. An acre-foot (af) is 325,851 gallons, the amount of water it takes to cover an acre of land one foot deep. One acre is about the size of a football field. An acre-foot of water can serve three households for a year in Aurora.

Q. How much storage does the City of Aurora currently have?
A. Currently, Aurora Water has 156,000 acre-feet in reservoirs. Storage increases resilience to droughts and system outages.