As fire crews work to snuff out the last hotspots of the Bighorn Fire, officials are now warning about the dangers of flash floods and have closed Mount Lemmon and Sabino Canyon for the foreseeable future.
Throughout July, scattered rainstorms and slowing winds had allowed firefighters to get the Bighorn Fire roughly 90 percent contained after it burned across 119,000 acres.
Pima County and the Forest Service announced last week that access to the mountain will be closed to most travelers until the end of October.
“Based on conversations with our [Burned Area Emergency Response] team, we have decided that the closure orders that we have out currently now will be consolidated into one closure order that will remain in effect until Nov. 1,” said CJ Woodard of the Catalina Ranger District.
Exemptions to the closure order include residents of the Summerhaven and Willow Camp areas, and special-use permit holders for establishments like Mount Lemmon SkyCenter Observatory and Department of Transportation. Road closures stretch around the majority of the burn area, including Bear Canyon and Redington Road.
Catalina State Park is not part of the order. While it is still closed, it will reopen when staff deem it ready to do so.
“At this time, the Sheriff’s Department is currently maintaining the road at the base of Mount Lemmon,” Pima County Sheriff’s Department spokesperson Marissa Hernandez said on Wednesday, July 16. “This is due to the fact that we still have an active fire near Catalina Highway. We ask that those Summerhaven residents that are utilizing that highway drive safely and that they notify the Sheriff’s Department immediately of any hazards they encounter. That may include seeing a fire near the roadway or rocks.”
Sabino Canyon also remains closed. Officials say they are concerned about standing dead trees and damage to trails along with the potential for flooding and subsequent damage. Sabino Canyon’s closure order will constantly be reassessed and portions that are safe to open will be opened as soon as possible.
When Pima County reopens Catalina Highway, public access to Summerhaven will be allowed, but access to the general forest may be limited. Those with cabin reservations atop the mountain can access the area, as long as the cabin is on private land and they can present proof of the reservation.
Forest Service officials say the road closure is being put in place for public health and safety with the oncoming monsoon rains. After a fire, terrain can become hydrophobic and result in greater flooding. In addition, damaged trees are more likely to be swept away.
“Post-fire watersheds are going to produce more runoff than they would if they were in unburned conditions,” said Lynn Orchard, chief hydrologist for the Pima County Regional Flood Control District. “One of the good news items is that we already have in place a very robust flood warning network that is used to help us during monsoon to be prepared and warn for flash flood and flooding hazards.”
Roughly 100 rain and flood monitoring sites are part of that system, 15 of which are in or near the burn area.
Signs of the danger of flash floods are already evident. On July 15, the Canyon del Oro wash near Edwin Road became choked with debris during an afternoon rainstorm. Pima County published a video showing a flash flood rolling through the wash, black with charred debris from the Bighorn Fire.
On the Pima County Facebook page, officials wrote that wildfires can “leave the ground charred, barren, and unable to absorb water. Even a light rain can produce devastating flash floods and mudflows, often with little warning.”
For public safety, Pima County has launched a Floods Follow Fires webpage, detailing how the Tucson residents can be prepared and “flood safe.” Precautions for a post-fire flood include having a supply of sandbags, establishing a safe family rally point, and creating a “Go Kit” with water, food, a flashlight, a phone charger, medications and other essentials. They recommend local homeowners also consider purchasing flood insurance.
Because of Pima County’s topography and proximity to mountains, there is sometimes little to no warning of impending flash floods or “debris flows.” Officials warn that Iin the event of moderate to heavy rainfall, it is best to take any emergency steps necessary to protect your life and property. Plan in advance to move away from the area and have a safety plan already in place.
During the Bighorn Fire’s peak, nearly 1,000 personnel were assigned to the job. That number was down to 59 last week as personnel continue with fire suppression repair efforts such as chipping, backhaul, and suppression rehabilitation.