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Project Overview#

Halligan Reservoir is an existing reservoir on the North Fork of the Cache La Poudre River (North Fork). It is situated about 25 miles northwest of the city of Fort Collins in Larimer County, Colorado. If approved, the Halligan Water Supply Project will enlarge the existing Halligan Reservoir by approximately 8,200 acre-feet. The Halligan Project aims to achieve the following goals:

Fort Collins neighborhood in fall

Increases Reliability and Resiliency

  • Provides a storage reserve for emergency water supply.
  • Increases drought security.
  • Improves water system reliability and flexibility.
  • Meets future water demands of the Fort Collins Utilities' water service area.

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Halligan Reservoir

Environmentally Responsible

  • Utilizes an existing reservoir.
  • Has a small footprint (only 138 additional acres inundated).
  • Requires no pumping, pretreatment, or additional infrastructure for water use.
  • Improves conditions on the North Fork of the Poudre River.

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Halligan Dam spilling

Cost Effective

The project is currently the most cost-effective option to meet Fort Collins Utilities' water storage and supply needs. Other water sources could cost much more. We evaluate the cost-effectiveness of the project at each milestone, ensuring it is the best course of action for the cost.

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Updates#

1041 Permit Application Submitted to Larimer County

On Aug. 14, 2024, the City of Fort Collins submitted an application to Larimer County for a 1041 permit. The application process includes county staff review, public hearings before the Larimer County Planning Commission followed by County Commissioners, and a final decision by the County Commissioners. 

The permit process considers all aspects of the project, including building the new dam, U.S. Highway 287 and access road improvements, and environmental mitigation and enhancements.

Final Environmental Impact Statement Released

On Oct. 23, 2023, the U.S. Army Corps of Engineers published a Notice of Availability for the Halligan Water Supply Project final Environmental Impact Statement in the Federal Register. This action is a significant milestone for Fort Collins Utilities and the Halligan Project. The project will provide added capacity in Halligan Reservoir to store Utilities’ water rights, enabling a more robust, resilient and reliable water supply for our current and future customers. 

Fish and Wildlife Mitigation and Enhancement Plan Released

In 2023, the Colorado Parks and Wildlife Commission and the Colorado Water Conservation Board approved the Fish and Wildlife Mitigation and Enhancement Plan. The approval marks a significant milestone for the Halligan Project.

The plan follows state law, which requires impacts be mitigated in a way that is ecologically reasonable and maintains a balance between the development of our water resources and the protection of our fish and wildlife.

Virtual Open House

In 2023, a virtual educational tool was developed to gather feedback on the Fish and Wildlife Mitigation and Enhancement Plan. As of July 2023, the plan was officially approved by the Colorado Parks and Wildlife Commission and the Colorado Water Conservation Board and is the State of Colorado's official position on fish and wildlife resource mitigation for the Halligan Project. Therefore, there is no longer the opportunity to comment or provide feedback. However, you can still access the interactive virtual tool here.

2022 Year in Review

From state and federal permitting to design work and dam concepts–see what was accomplished in 2022. 

Explore Halligan Reservoir#

Halligan Reservoir

Halligan Reservoir north shore.

Halligan Dam

Existing Halligan Dam.

Halligan Dam

Existing Halligan Dam and North Fork of the Poudre River looking south west.

North Fork of the Poudre

North Fork of the Poudre River looking south downstream of Halligan Dam.

Halligan Reservoir

Halligan Reservoir in the spring.

Halligan Reservoir

Aerial view of Halligan Reservoir.

Halligan Reservoir

Halligan Reservoir and existing Halligan Dam.

Halligan Dam

North Fork of the Poudre River downstream of Halligan Dam, looking north.

Halligan Dam

Top of Halligan Dam looking south.

Halligan Reservoir

The Halligan Reservoir shoreline.

Halligan Reservoir

Halligan Reservoir inlet.