The Coconino National Forest’s Flagstaff Ranger District and the City of Flagstaff will both soon begin repairing flood damage to the Inner Basin water pipeline and along nearby forest roads.
The pipeline, which was damaged due to post-wildfire flooding caused by the 2022 Pipeline Fire, has been losing millions of gallons of water each day.
The project – formally titled the Inner Basin Waterline Post Fire Repairs Road Reconstruction Project – is outlined in a decision memo that was recently signed into effect by Coconino NF Supervisor Aaron Mayville.
“This is a pinnacle achievement for the project and allows the project to proceed with restoration construction, establishment of staging areas, and perhaps most critical – connecting and armoring our water supply of 2 to 4 million gallons of water per day to our community,” said David Pedersen, Project Manager with the City of Flagstaff.
The 13-mile-long Inner Basin water pipeline is a critical piece of the city’s water supply portfolio that delivers water from sources located in the San Francisco Peaks to the Flagstaff area.
Repair work will address 45 locations along Schultz Pass Road (Forest Road [FR] 420) and Waterline Road (FR 146) that were damaged due to storm flows, including three known breaks in the waterline pipe. While much of the pipeline itself located within the burn area is intact, some sections are broken and unsupported due to the loss of roadway.
Construction will repair the areas around the water pipeline to provide support in addition to reducing further degradation of these areas.
This work will enable the Inner Basin water pipeline to operate at full capacity while improving the overall road conditions.
The City of Flagstaff has been a wonderful partner to work with on the Waterline project,” said Acting District Ranger Geordie Beck. “All those involved in this project are focused on getting the waterline and associated infrastructure up and running for the community following the devastating fires last year. We will continue to work hand in hand with the city as the project moves forward to ensure the community has access to quality water.”
The Inner Basin pipeline has been serving the City of Flagstaff for more than 120 years and provides roughly 20 percent of the city’s potable water supply during the summer.
Construction is expected to begin mid-July 2023 and is anticipated to last through November 2024. Forest visitors are asked to remain cognizant that active construction is taking place along both Schultz Pass and Waterline roads. Waterline Road is closed to all hikers, bikers, and horseback riders due to active construction and heavy equipment and is always closed to motorized vehicles.
