Cleaning up after US89A flood and mudflow

The Arizona Dept. of Transportation is working to restore US89A after heavy rainfall on August 9 covered miles of the highway between Marble Canyon and Jacob's Lake with mud and boulders.


The update from ADOT explains that the House Rock Flood was caused by approximately one-and-a-half inches of rain in less than 20 minutes, according to the National Weather Service. As a result, crews were busy last week clearing mud and debris that collected on the roadway and in box culverts underneath the roadway to prevent possible damage during future storms [bottom, credit ADOT].

The crews, aided by heavy equipment including an excavator and road graders, removed some boulders that were as large as 15 feet in diameter that traveled approximately two miles from the Vermillion Cliffs [top, credit, ADOT]

Currently, less than one-half mile of US 89A is restricted to one-way traffic at milepost 551, approximately 12 miles west of Marble Canyon. Due to the remote location and low traffic volumes, there have little to no delays in this area.

“We have now moved into Phase Two of the recovery efforts following the House Rock Flood,” said ADOT Flagstaff District Engineer Audra Merrick. “Crews worked tirelessly last week to open inlets to protect the roadway from future rainfall and our engineers have completed their assessment for possible damages. Fortunately, there were no major damages to the infrastructure, but we have identified significant repairs that need to be completed before we fully reopen the highway.”

Prior to re-establishing two lanes of traffic at this location, ADOT will repair three box culvert structures and drainage channels that allow flood waters to safely pass underneath the roadway and perform additional roadway/pavement work.

ADOT is currently pursuing a contractor to work on the repairs. As of August 17, there is no estimate for when the repairs will be completed.

[modified from the ADOT announcement]