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Halligan Water Supply Project

Project Overview#

Halligan Reservoir is an existing reservoir on the North Fork of the Poudre River, 25 miles northwest of Fort Collins. If approved, the Halligan Water Supply Project will enlarge Halligan Reservoir by approximately 8,200 acre-feet.

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

  • Uses an existing reservoir.
  • Small in size (only 130 additional acres inundated).
  • No pumping, pretreatment or added infrastructure is needed to use water.
  • 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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The U.S. Army Corps of Engineers (Corps) released a draft Environmental Impact Statement (EIS) in November 2019. The Corps will develop a final EIS before making a permitting decision on if Halligan Reservoir can be expanded.

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2021 Year In Review

From state and federal permitting to preliminary design work and dam concepts– see what was accomplished in 2021. 

Potential New Dam Concept Identified

Preliminary design efforts revealed that two viable dam concepts exist for enlarging Halligan Reservoir.

City Council Quarterly Updates

Find the past and present City Council quarterly updates here.

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 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.