In the June 18, 2018, photo above, ash from the so-called 416 Fire burning 10 miles northof Durango, Colorado, stained the Animas River black, raising concerns about the runoff's environmental impact on local waterways.

(Courtesy of the Mountain Studies Institute )

At a Glance

Ash from the so-called 416 Fire burning in Colorado turn the Animas River and Hermosa Creek black. The murky water has raised concerns about the environmental impact on the bodies of water and their aquatic life.

Waterways in Colorado were stained black this weekafter rainfall washed ash from the so-called 416 Fire into the waterway.

Posts shared on social media showed the murky water flowing in the Animas River, as well as one of its tributaries, the Hermosa Creek.

“Durango, Colorado, received 0.84 inches of rain in two days following months of very dry weather,” said weather.com meteorologist Jonathan Belles. “During a first rain following a drought, most rainwater runs off the land rather than seeping into the ground due to the harder nature of the soil after dry conditions. This combined with the ash and soot from the 416 Fire likely helped turn the waterway black.”

(MORE: )

La Plata County Office of Emergency Management director Butch Knowlton told The Durango Herald that the rainfall was the for giving the region a good dose of rain without triggering more hazards for the residents.

However, he warned that there will be landslide and flash-flooding threats in the area for years to come.

“We just have to be aware of the fact there’s a lot of material up there that can come down with a heavy rain,” said Knowlton. “That’s what we’re going to be watching.”

The Hermosa Creek is stained black by ash from the so-called 416 Fire burning in Colorado.

(Courtesy of the Mountain Studies Institute )

Water quality and marine life in the bodies of water are also threatened. The debris and nutrients that seep into the waterways can cut off oxygen in the water and raise the waterways’ pH balances. This can kill fish by causing them to go into shock.

Colorado Parks and Wildlife senior aquatic biologist John Alves told the Herald that fires could also wipe out trees that cast shade over the bodies of water, creating the cooler climates that fish prefer.

Though the ecological issues are concerning, Alves says they only last for a couple of years, as fish and other marine species rebound quickly.

Researchers with the Mountain Studies Institute monitored the of the two tributaries Friday through Monday and have been analyzing samples from them for sediment, nutrients and metals, according to the organization’s website.

The 416 Fireburning 10 miles northof Durango has consumed more than 50 square miles and is 35 percent contained as of Wednesday. Residents of more than 2,000 homes were forced to evacuate due to the blaze.

It was sparked around 10 a.m. June 1 and its cause remains unknown.