Matrix performed an assessment of Colordao Springs Utilities’ (CSU)10-million-gallon McCullough Reservoir located on the United States Air Force Academy (USAFA) property. CSU has very few record drawings for the reservoir and knew that only minor cleaning and routine maintenance had been performed inside the underground concrete reservoir since it construction. The first of the reservoir’s two isolated chambers was built in 1996, and the second chamber was added in 2001.

McCullough Reservoir and an adjacent reservoir service almost 80% of all Colorado Springs water and could only be taken out of service for a limited time in November. To perform the assessment, Matrix coordinated with CSU Operations and USAFA security personnel to ensure access.

The assessment proved that the older of the reservoir’s two chamber’s 72-inch influent and effluent slide gates were leaking, and general safety updates were needed, including new ladders and platforms for use during maintenance. After a lifecycle cost analysis, it was determined that the best solution for fixing the leaking slide gates was to replace them with 72-inch butterfly valves.

During construction, it was discovered that the slide gate frame embedded in the concrete wall was not suitable for welding to the new butterfly valve. Our Team completed a quick design and determined thata steel plate could be bolted to the apparatus and provide appropriate support for welding the butterfly valve. Due to the time constraints associated with construction, the design was expedited. Matrix worked closely with the contractor to procure the necessary materials and get the valve installed quickly and safely.