University officials have begun taking steps to protect medical facilities from potential mud flows following the Bonneville Fire, which scorched 572 acres of the Wasatch foothills last month. Although an assessment by the U.S. Forest Service's Burned Area Emergency Response indicates that the fire did not significantly damage soils, the area remains at an elevated risk for debris or mud flows for up to three years while vegetation recovers.
To mitigate potential damage, university officials, assisted by more than 100 community volunteers, have placed Jersey barriers and 2,000 sandbags along the Bonneville Shoreline Trail. These measures are intended to reduce the chance of rain-entrained debris reaching the Huntsman Cancer Institute's hospital and research facilities during the upcoming monsoon season.
Phil Chaffee, the U of U Health’s associate executive director of emergency management, stated that concrete Jersey barriers have been placed along 700 feet of the Red Butte and Bonneville Shoreline trails above the institute. Chaffee noted that these barriers and sandbags are designed to redirect and slow water flow so that storm drains can manage the runoff, rather than attempting to stop the water entirely.
The Bonneville fire was triggered on June 20 by human activity. The burned area spans Mt. Van Cott, from the north side of Red Butte Canyon to the mouth of Dry Creek Canyon, consisting of 319 acres within the Uinta-Wasatch-Cache National Forest and 253 acres of private land.
According to the BAER report, there is a 50% probability of triggering a debris flow in the first year if rainfall intensity reaches more than 32 millimeters per hour. The area at the mouth of Red Butte Canyon has been identified as having the lowest threshold for such an event. Salt Lake City Fire Department deputy emergency manager Tom Simons noted that because the fire passed through quickly, 93% of the burned area experienced low burn severity with minimal soil change.
The placement of sandbags and barriers is considered temporary by officials. These measures will remain until Forest Service reseeding efforts allow new vegetation to stabilize the soils. The BAER report anticipates that ground cover may approach pre-fire conditions within one to three years, though the area remains susceptible to invasive species following the disturbance.
