The 540-acre wildfire that burned four days on the south side of I-80 is contained. But extreme rain and flash floods Saturday caused additional concerns.
On Sunday, the Uinta Wasatch Cache National Forest Burned Area Emergency Response Team visited the Parleys Canyon Fire site. Coordinator Brendan Waterman said they evaluated the burn area on the eastbound lanes on I-80. Monsoonal rains helped to quell the fire, but on Saturday, the rain presented a different problem. Due to the burn scar leaving the area barren, flash floods deposited debris 75 feet above the highway.
"What really sets that off is when it burns, you lose your canopy cover from your vegetation, you lose your ground cover from any organic material that would have been on the surface of the soil, and then sometimes a natural water repellent layer develops on the surface of the soil, and then the soil itself can become destabilized from the heating. When that gets hit with short duration, high-intensity rainfall, it essentially accelerates the runoff."
He said burn scar conditions can prevent water from sinking into the ground, and cause more severe conditions to occur.
"So, you get more runoff. So, the water's not going down. It's essentially just rolling off the slopes really fast, and as it accumulates in the channels, you know, transports burned material that was on the hillslopes. Then the volume of water that's traveling through the channel can scour out the channel and start moving a lot of the material that's in the stream channel bottom."
Saturday's flood did not cause damage to the interstate, but the threat of future flash floods will remain for three to five years while the land recovers with new growth.
