Hold off anglers: CPW says some Colorado rivers are too hot and shallow to fish right now

Right now, the Colorado River, Yampa River, Dolores River and San Juan River are facing a voluntary closures due to high water temperatures and low flow rates. So, what does that mean? 

"Voluntary closures are when Parks and Wildlife asks anglers not to fish because conditions are pretty stressful for the fish," aquatic biologist with Colorado Parks and Wildlife Kendall Bakich said. 

Too much stress, the fish die. We want fish in our rivers for many reasons, one of them being fishing. Fishing tour guide Chris Kish in Glenwood Springs knows this very well. His livelihood depends on there being a healthy fish population in our rivers. 

"It was a nuclear bomb last year," Kish said, referencing last year's hot water temperatures. "Most of us though we certainly lost a lot of fish in the Colorado. Turns out they are doing just fine," he said.

Fine, if not stressed according to CPW. Biologists have measured temperatures above 71 degrees, which is the "acute standard," meaning anything above that or besides that (like low flow or other issues for fish) would be potentially deadly. Trout tend to enjoy temperatures closer to the low to mid 60's and do not regulate their own temperature aside from trying to find colder waters. 

Bakich said that is why even small changes can cause drastic effects. 

"Just a few degrees, just like us, we can get a fever a few degrees above our standard 96-97 degree standard and that is when we are considered stressed," Bakich explained. "In some way or another, same with fish."

She also said they are measuring flows in her region at around half of what they should be compared to the standard at this time of year. 

This now marks the fifth year when there have been on-and-off voluntary closures for different parts of Colorado. Bakich said it would not surprise her if this is not the last one we had in Colorado.

"Water availability is certainly an issue, snow pack can be a huge problem." Bakich said. "These increasing summer temperature with global climate change, we are experiencing those as well. The availability of our rain in the summer, all are factors."

Bakich said water is expected to be added to those rivers in the coming weeks which has the potential to drive down the temperatures, and allow for the lifting of those closures.