Officials Watching Burn Scars As Risk Of Mudslides, Flooding Grows
LAKE POINT, Utah – The 2,000-acre Green Ravine Fire burned away from homes in Tooele County but left the area with a major risk of debris flows for years to come.
The human-caused fire incinerated all of the vegetation on the mountainside last week. The huge burn scar now presents a problem for debris flows into the neighborhood below.
“The whole area burned intense,” said National Weather Service meteorologist Glen Merrill. “It burned hot. There’s hardly any vegetation left.”
After each of Utah’s major fires, the National Weather Service assesses what kind of storm will trigger debris flows. Hydrologist Brian McInerney and Merrill went up in the state helicopter to get a bird’s-eye view Thursday while hiking the lower area.
“Within a quick amount of time, we figured out that this is a problem area, that we are going to have debris flows,” McInerney said.
The western edge of the burn scar, where the fire burned the hottest, worried them the most. From the air, they were able to see part of the burn scar that funnels into a neighborhood below a train trestle.
“If we have a thunderstorm that we anticipate is going to put down a half-an-inch in 30 minutes, then we will issue a flash flood warning for debris flow specifically for that area,” McInerney said.
That kind of storm hit Salt Lake City Wednesday, dropping over a half-inch of on rain on the city in less than 30 minutes.
The work they did today gives them the critical information they’ll need on stormy days.
“When I’m on shift, and I see an intense thunderstorm, it’s pretty grippy trying to decide if you’re going to have a big issue or not for protection of the people below,” Merrill said.
However, Merrill and McInerney said not all areas within a burn scar are risky.
They will make radar map overlays of debris flow threat areas from their assessment. Those overlays pinpoint areas of concern on burn scars across the state. This new tool helps them more accurately forecast debris flows.
They’ll meet with Tooele County emergency managers to share what they discovered and monitor the area, along with other Utah burn scars whenever big storms develop.
“If you live down in this development, right below this basin, keep your eye on the weather,” McInerney said.