Overview

In cooperation with other communities and water districts, Longmont is participating in the development of the Chimney Hollow Reservoir, a new raw water storage reservoir to be constructed west of Carter Lake. This project has also been referred to as the Windy Gap Firming Project. The purpose of the reservoir is to capture and store Windy Gap water, which the City already has a right in, to improve the reliability of this supply. The project will provide storage capacity to meet current and future water supply needs.

Learn more from the project’s managing agency, Northern Colorado Water Conservancy District; visit the Chimney Hollow Reservoir Project webpage.

Longmont’s Involvement

In the fall of 2017, City Council decided that the City of Longmont would participate in the project at a capacity level of 8,000 acre-feet of water secured for Longmont (a volume similar to approximately 2/3 the size of Union Reservoir).

Costs

The total estimated cost for Longmont to secure (own) 8,000 acre-feet of water is $59.5 million.*

• The City has invested $6.8 million (as of fall 2019) and has an estimated remaining contribution of $52.7 million.*
• In the November 2017 Boulder County Coordinated Election, Longmont voters approved the issuance of $36.3 million in bonds to help fund the project. Repayment of this amount is funded using a combination of rate revenue and development fees.
• Other funding for the project is provided by money reserved for water storage projects.

*Note: As in all construction projects, actual cost of construction will not be finalized until construction is complete.

Supplemental documents for all City Council meeting items and videos of past meetings can be found on the Agendas & Minutes webpage.

Contact

If you have questions or would like additional information, contact Water Resources.