The downpour dropped more than an inch of rain in upper Waldo Canyon within 35 minutes Wednesday evening, the Colorado Springs Gazette reported.
"Under any other circumstances, that wouldn't really be that big of a deal. But since we do have the burn scar in that area, that creates a very, very serious situation," meteorologist Patrick Cioffi said.
El Paso County Sheriff's Office spokesman Lt. Jeff Kramer said that 20 to 25 vehicles were either swept off U.S. Highway 24, or got stuck in mud.
"This seemed to have basically been an episode that affected us most up on Highway 24," Kramer said. "I think the lesson learned here is that this was a demonstration of the speed and the power in which that water can move."
Officials closed the highway for about 3 hours after the flood.