Project Overview
The Source Water Resiliency Project focuses on rehabilitating aging raw water conveyance infrastructure near the historic mining townsite of Irwin, located approximately 7 miles upstream of the Town of Crested Butte at the headwaters of Coal Creek. The Town holds a 367-acre-foot water storage right in Lake Irwin, which is essential for both the municipal drinking water supply and maintaining instream flows in Coal Creek.
The project will enhance site access, operations, maintenance, and safety, while improving ecological outcomes such as aquatic habitat, wildlife support, recreation, and downstream water rights—including those held by the Town, agricultural users, and CWCB instream flow rights.
Project Details
Huge thank you to Colorado River District and Colorado Water Conservation Board for Design and Engineering grants and your support.
- Infrastructure Needs and Condition Assessment
Extensive dam breach modeling, geotechnical studies, and condition assessments conducted by the design team have confirmed the urgent need to replace the aging Lake Irwin tunnel, valve, and piping infrastructure. Key existing components include:
- A submerged timber-set tunnel built in 1877
- A concrete valve shaft and 16” gate valve from 1935
- A 430-foot, 16” outfall pipeline added in 1986 to replace a collapsed tunnel
Underwater investigations helped confirm the need for full replacement. Two key videos document these inspections:
- Lake Irwin Raw Water Infrastructure Intake – What the Underwater Rover Camera Sees: Footage of the 1877 timber-set tunnel prior to the 1935 valve, which connects via the 1986 pipe to Coal Creek. (Sonar imagery not shown in this video)
- Lake Irwin Raw Water Infrastructure Intake 2 – Diver Repair: Footage of a diver temporarily patching a large hole in the intake. This section is scheduled for full replacement.
- Engineering and Desgin
- Carollo Engineers was awarded the design contract on July 6, 2021, for 30%–100% design phases.
- Schnabel Engineering joined the project when the system was reclassified as the Coal Creek Dam.
- Engineering work included geotechnical borings, condition assessments, and land/easement surveys at Lake Irwin.
- Underwater diver and ROV video inspections of the 1877 tunnel were also completed.
Stakeholder Coordination
The project involves coordination with:
- Colorado Parks and Wildlife
- U.S. Forest Service
- State Engineer’s Office
- Montrose Dam Safety Office
- Construction Plan & Funding
Construction Plan
The project will use a Construction Manager at Risk (CMAR) delivery method. Moltz Construction was awarded a contract on January 7, 2022, for design reviews and Guaranteed Maximum Price (GMP) development.
Project Funding
- Design & Engineering Grants:
- $25,000 from the Colorado Water Conservation Board (CWCB)
- $42,000 from the Colorado River District
- Construction Grants (Received, not yet activated):
- $500,000 from CWCB (March 2023), including:
- $350,000 from State Aging Infrastructure
- $150,000 from the Gunnison Basin Roundtable
- $300,000 from the Colorado River District (April 2023)
- $50,000 from the Upper Gunnison River Water Conservancy District (March 2023)
- $500,000 from CWCB (March 2023), including:
Note: These grants expire in December 2028 and may need to be reapplied for closer to the projected construction start in summer 2027.
The Town is working with Senators Bennet and Hickenlooper’s offices to pursue Congressionally Directed Spending (CDS) for the construction phase and plans to apply for FEMA Hazard Mitigation Assistance (HMA) funding in Spring 2025. Both federal sources will be essential to advancing the Coal Creek Dam upgrades.
- Design & Engineering Grants:
Thanks to Colorado District River for this 2 minute video of Lake Irwin Valve and Piping project.