Monsoon rains bring ash, debris down from Bighorn burn scar

TUCSON, Ariz. (KOLD News 13) -The Bighorn Fire may not be burning anymore, but the remnants of it are still very apparent. Aside from burned trees and brush on the Catalinas, it’s an issue during monsoon season.

The first storms of monsoon season are welcome in any drought or desert, but when they are as intense as ones seen the second week of July and right after the largest fire seen in our area in years, it is a cause for concern. The water running down the Santa Cruz was black and likely around two feet deep Wednesday.

“It’s called the first flush,” said Joseph Cuffari of the Pima County Flood Control District. “So, it’s where the charred debris actually comes down with a rainstorm event. We can probably expect conditions like this for 4-5 years just based on the burn intensity and cumulative effects from wildfires over the years.”

The burn scars create a perfect slide for heavy storms to push debris, ash and excessive amounts of water down the mountain, into the washes and likely over roads—potentially more.

“What we’re most worried about right now, (with) Bighorn Fire and just general monsoon, is we’ve had these cumulative rain events the last few days,” Cuffari said. “So, soils are starting to get super saturated, which means the water is not being able to infiltrate which could lead to water just sheeting across and exacerbating that flood threat and flood a hazard potential.”

The Pima County Flood Control District has done several projects, added more monitors and improved banks along the CDO and Pima washes, likely to fill quickly during flash flooding events. Still, the CDO wash raged Wednesday morning. In the Golder Ranch Fire District jurisdiction, the department was expecting heavy flow.

“These storms… they’re dropping quite a bit of rain, and our partners over at the National Weather Service say anything over an inch of rain an hour over the Bighorn scar is going to produce some flash flooding in the area, and that’s what we saw this morning,” said Capt. Adam Jarrold, public information officer for Golder Ranch Fire District.

The slope of the mountains means the water moves fast and notifications may not be quicker—so GRFD said to be aware of your surroundings and patient when it comes to crossings. They, along with the Flood Control District, urge people to sign up for notifications through the county. To sign up, go to myalerts.pima.gov.

Copyright 2021 KOLD News 13. All rights reserved.