Water Supply and Planning

The City and County of Broomfield (CCOB) has two primary sources of water: 

Watch a video about the Colorado-Big Thompson Project

Broomfield is also a participant in the Chimney Hollow Reservoir Project (CHRP). CHRP will provide valuable storage for Windy Gap project water and will increase water supply reliability for Broomfield customers.

On June 5, 2025, Northern Water issued a news release stating that water quality sampling at Chimney Hollow Reservoir indicated the presence of uranium-bearing minerals in water that is temporarily stored at the site. The uranium at Chimney Hollow is naturally occurring in the granitic rock formations that were quarried onsite to supply material for the dam. Northern Water stated that this issue will require close monitoring and management when filling Chimney Hollow Reservoir and that Dam safety and other tests will continue over the next two to three years as mitigation strategies are being pursued and implemented.

Important Notes for Broomfield as a CHRP participant:

  • Chimney Hollow Reservoir has not been filled and won’t be full until the end of 2026.Filling is scheduled to start in August and will take many months.
  • Broomfield is not currently using water from the Chimney Hollow Reservoir and does not expect to use water from Chimney Hollow Reservoir until 2027, at the earliest.
  • At this time, there is no indication that this finding will result in increased costs for the CHRP project.Costs for testing and monitoring are covered by Northern Water’s existing operational funds.
  • Broomfield water quality continues to be of high quality and meets all regulatory and public safety requirements.

Broomfield staff continues to be actively engaged in this issue, and attends all the Windy Gap participants’ and legal representative meetings.

For more details on the Chimney Hollow Reservoir water quality issue, visit the Northern Water Chimney Hollow Reservoir Project web page, including the news release (Chimney Hollow Reservoir Nears First Fill Operations) within the “News” section on this page.

Broomfield's Water Reuse System

In addition to its potable (drinkable) water supply, Broomfield also has a robust reuse (non-potable) water system. The reuse water system allows Broomfield to use treated wastewater effluent (liquid waste that can be discharged into a body of water) a second time for irrigation and other non-potable purposes. The keystone of CCOB’s water efficiency efforts is the non-potable distribution system, also known as the reuse system. CCOB’s reuse system provides water to approximately 940 acres of irrigated parks in the city. There are approximately 1,500 additional acres of non-city owned areas served by the reuse system, including Arista, Flatirons Mall, Legacy High School, Anthem and Interlocken Business Park along Highway 36.

The reuse system is extremely beneficial because it allows CCOB to expand its water supplies beyond a single, one-time use and reduces the amount of treated domestic drinking water that would otherwise be needed for these irrigation purposes. Broomfield’s reuse system addresses as much as 20% of the overall water demand in the city.

Water Conservation 

For water conservation tips and tricks, information about rebates for water efficiency and landscape watering tips, visit Water Efficiency. 

For additional information, please email WaterUtilities@broomfield.org.