I-17 101 traffic interchange

ADOT adds capacity to US 180 drainage system in Flagstaff

ADOT adds capacity to US 180 drainage system in Flagstaff

August 9, 2023

Joint effort with Flagstaff accelerated repairs, additional drainage line

FLAGSTAFF – The Arizona Department of Transportation has completed interim repairs and improvements to increase the capacity of a stormwater drainage system along US 180 in northwest Flagstaff, in an area below the Pipeline Fire burn scar.

Heavy runoff from a record-setting snow season earlier this year exposed damage to an existing drainage pipe parallel to US 180, also known as North Fort Valley Road, between the Schultz Creek culvert and Stevanna Way.

ADOT and the city of Flagstaff collaborated on an accelerated project to repair the existing drainage pipe and add a second nearby 48-inch interim pipeline. Flagstaff provided an easement for the new pipeline.

“We need to emphasize that these are interim improvements,” said Brenden Foley, district administrator for ADOT’s Northcentral District. “The new line provides an important increase in the system’s drainage capacity while Flagstaff plans for future capacity improvements. We appreciate the city’s help on this project.”

Stormwater damage had caused sections of the ground above the old pipeline parallel to southbound US 180 to sink. Repair work included installing a new pipe and pavement and the replacement of a sidewalk and driveways, including those for the city’s Fire Station No. 5. 

“The partnership between the city and ADOT has been very successful,” said Flagstaff Mayor Becky Daggett. “This involved collaboration and accelerated action on behalf of neighborhoods in the area. I want to thank the Grand Canyon Trust and other property owners for working with us on the easement for the new interim drainage line. Our team is already working on the design for a permanent drainage system that will handle much more runoff.” 

Flagstaff has installed other storm runoff mitigation measures along Schultz Creek above US 180, including detention basins. 

Real-time highway conditions are available on ADOT’s Arizona Traveler Information site at az511.gov. ADOT also provides highway condition updates via its Twitter feed, @ArizonaDOT.

US 180 drainage improvements (ADOT photo Aug. 23)