I-17 101 traffic interchange

ADOT ready to address post-Slide Fire flood issues on State Route 89A

ADOT ready to address post-Slide Fire flood issues on State Route 89A

July 8, 2014

PHOENIX — The Slide Fire has been extinguished, but the threat of flash floods, mudslides and rock slides is real in the Oak Creek Canyon area. Just in the last week, the Arizona Department of Transportation has been forced to temporarily close a portion of State Route 89A between Sedona and Flagstaff on three occasions due to flooding and debris flowing along the burn area near the highway.

Large-scale wildfires can dramatically alter the vegetation and soil conditions, which increase the risk of flooding from monsoon rains through the burn and downstream areas. Fire debris, mud and silt clog streambeds and drainage culverts, thereby increasing the likelihood of flood damage.

Following the wildfires within Coconino National Forest, ADOT has been preparing to combat potential flooding issues along SR 89A north of Sedona. While ADOT has no plans to close SR 89A for the entirety of the monsoon season, there is the possibility that the highway could be closed periodically due to flash floods and other risks, particularly during heavy rains.

In an effort to minimize the impact of post-Slide Fire risks, ADOT has initiated several flood-damage mitigation measures recently, including staging heavy equipment, including road graders, in the Oak Creek Canyon area and positioning staff in the canyon during adverse weather conditions.

Before, during and after the most recent monsoon storms during the Fourth of July weekend, ADOT crews have been clearing accumulated debris from drainage culverts and roadside ditches. Additional post-fire maintenance includes repairing roadway embankments along burned out slopes within ADOT’s right of way in an effort to restore the vegetation.

Maintenance crews have also replaced burnt erosion control features such as logs, rock dams and “wattles,” which are straw-filled canvas tubes that help keep the soil and debris off highways, in preparation for potential floods.

ADOT, which is responsible for maintaining areas within the highway right of way, is working in coordination with the other governmental jurisdictions, agencies and private property owners whose responsibility includes restoration and flood-prevention work on the damaged watershed.

When the National Weather Service forecasts potential thunderstorms in the canyon, ADOT works closely with the Coconino County Sheriff’s Office, Sedona Fire and Police Department, U.S. Forest Service, and the Arizona Department of Public Safety to set up informational checkpoints along SR 89A near Slide Rock State Park and Vista Point overlook to warn motorists about the potential flood risks and distribute flood hazard safety pamphlets. More than 4,500 pamphlets were distributed during the Fourth of July weekend.

“ADOT is partnering with DPS, U.S. Forest Service, Coconino County, Coconino County Sheriff’s Office, city of Sedona, Sedona Fire Department, Sedona Police Department, and Yavapai County to ensure the safety of the traveling public in the Oak Creek Canyon area,” said Flagstaff District Engineer Audra Merrick, and reminds travelers, “Oak Creek Canyon is a beautiful place to visit, particularly in the summer, but drivers need to use caution and be prepared for what could happen.

“Drivers need to be alert for changing weather conditions, be tuned to weather reports and be aware of the risks, which could include flowing debris, flash floods, mudslides and rockslides.”

ADOT is warning motorists traveling between Sedona and Flagstaff to be aware that changing weather conditions could create hazardous driving conditions in matter of minutes. Every motorist should be aware of the following monsoon safety driving tips:

  • Don’t risk crossing a flooded wash, even if it doesn’t look deep. Water is a powerful force that should not be underestimated.
  • Do not drive around “Road Closed” signs. You risk your life and face being cited under the state’s “Stupid Motorist” law.
  • If traffic lights are out, treat an intersection just like a four-way stop.
  • Expect the unexpected. Have extra supplies, including an emergency kit and drinking water, in case you experience an extended highway closure.
  • Storm runoff can loosen boulders and rocks on slopes above highways. Stay alert in rockfall-prone areas.

Additional information on post-wildfire recovery and mitigation can be obtained through the Arizona Division of Emergency Management at www.azein.gov.

For the most current information about highway closures and restrictions statewide, visit ADOT’s Travel Information Site at az511.gov, follow us on Twitter (@ArizonaDOT) or call 5-1-1.