Flash flooding still a threat 5 years after Waldo

Five years after Colorado's second-most destructive wildfire tore through a large swath of El Paso and Teller counties, flash flooding still remains an issue.

"It's our new normal," said Gordon Brenner with Colorado Springs Emergency Management.

Brenner said it could be 30 years before vegetation along the burn scar reached the level it was before -- meaning likely, flooding will remain an issue for decades to come too.

"We've had satellite imagery taken and analyzed by the U.S. Geological Survey, and we're up around 70 percent revegetation on the burn scar. That's a good thing overall."

But...

"It has not alleviated the flash flood danger that we have from the burn scar," Brenner said, explaining that most of the new vegetation is grass and small bushes, which can't hold back the water like the trees used to.

"[The trees] would not only break up the rain when it fell, but they would also absorb a lot of that water. Those trees are no longer present, so the grasses that are up there now, the small woody bushes, they cannot possibly take on what the trees were doing."

It's one reason why mudslides have become much more prevalent since the 2012 wildfire.

"The trees were also holding the hill slopes in better place during that time. Since we don't have them, we are at risk of mudslide.

"What we're concerned about coming down is a bulked river flow. So it's water, but it's full of this material that is suspended in the water. And as it comes through, it thickens up and becomes very dangerous. It can move cars, it can move trucks. It can destroy things in its way. Think of it like sand blasting through a bridge, and it will actually strip concrete."

Brenner said the new vegetation was helping some, which is partly why the last couple of years haven't been as bad as the years immediately following the fire.

"It was really bad in 2012 and 2013 because there was literally no vegetation up there. Now we've got some vegetation -- it's helping, but we're not out of the woods.

A new problem that started last year: dead trees scorched in the fire are beginning to fall.

"Those will get into the drainages and start moving down. We have protection in place for that -- nets in certain canyons, and those nets are designed to capture the trees as they come down," Brenner said.

As the eastern part of Colorado Springs knows well, it's not just areas near the burn scars that are at risk of flash flooding.

"When it rains, especially up in the mountains, that water is coming down the hill and the city of Colorado Springs is in the path. Most of the drainage's on the north side of Pikes Peak. ... Flooding potential is really across the whole city. Anywhere that we have a drainage coming through -- think Monument Creek, Cottonwood Creek, Sand Creek -- all of those have the city storm water system flowing into and they can become overflowing with water really in just a few minutes. We get really intense rain showers here. So we could get several inches of rain in, like, 15-20 minutes that's going to overwhelm the systems and they'll all start overflowing."

The city of Colorado Springs is holding a meeting Thursday night to make sure the community is prepared for flash flooding. The U.S. Forest Service will in attendance to discuss the things they are doing to try and alleviate the danger.

The meeting starts at 6:30 p.m. at Chipeta Elementary, located on 2340 Ramsgate Terrace.