At 2:30 a.m. Sunday, a break in the Central Arizona Project (CAP) canal was reported near Bouse by local water operators.
Water from the breached canal swept across the desert, and Highway 72 was closed by the Arizona Department of Transportation and Department of Public Safety for precautionary reasons.
Maintenance crews arrived at the scene shortly after the breach was reported, and the crack has since been isolated.
CAP has since suspended all water pumping from the Colorado River and water loss from this morning's breach is estimated at about 400 feet-acre.
There is no timetable for the re-opening of Highway 72.