Local waterways heating up
Water temperatures cause concern for fish
Times Staff Writer
Originally published 2012-07-12



The fishing isn’t the only thing that’s been hot throughout the drought-ravaged waterways of the Western Slope this summer.

Despite fishermen reporting successful seasons on numerous bodies of water across the region — including many of their favorite honey holes in the Gunnison Valley — it’s the high temperatures in Colorado’s streams that have been cause for concern among those with the fish’s best interests in mind.

And now those concerns have hit home, as Colorado Parks and Wildlife (CPW) implemented this week a “voluntary” closure of Tomichi Creek (see sidebar, page A8). The decision follows suit with at least four other streams on the Western Slope.

With water temperatures reaching the mid-70s in recent weeks, the health of trout populations in Tomichi Creek is the main reason for taking extra precaution.

“We’ve received rains that have made temperatures much lower in recent days, but on most days it’s in the mid-70s and tough on the fish,” said CPW aquatic biologist Dan Brauch.

Brauch went on to say that when water temperatures reach about 72 degrees and warmer for a prolonged period of time, fish face a significantly higher rate of mortality. Even around 70 degrees, lower oxygen and higher stress levels then make it harder for fish to recover once hooked and taken from the water.

“It’s definitely something we’re keeping close tabs on,” said Brauch. “When fish are handled and additional stress is placed on them, it can cause mortality.”

The good news is, the majority of other streams in the Gunnison Valley are in fairing better. The Lake Fork of the Gunnison River has reached 70 degrees on a few occasions, but the East, Gunnison and Taylor rivers have not risen above the mid-60s.

Low flows and warm water temperatures led CPW to place a voluntary closure of the Yampa River in Steamboats Springs late last month. Five days later, CPW suggested restrictions be placed on fishing the White River, near Meeker, during certain times of the day.

Late last month, Trout Unlimited (TU) joined the campaign by asking Colorado anglers to voluntarily restrict their fishing on portions of the Fraser and Upper Colorado rivers.

“The combination of drought conditions, extensive diversions and record heat is putting enormous stress on fish populations,” Drew Peternell, director of TU’s Colorado Water Project, said in a press release. “With low flows and high water temperatures, trout populations will be in survival mode this summer.”

The last time a voluntary closure was put into place on a local waterway was during the summer of 2002, when temperatures on the Lake Fork eclipsed the 72-degree mark for consecutive days. Fishermen were asked to refrain from fishing the stretch of water that meanders north from Lake City during the warmest hours of the day.

Dan Hall, owner of Dan’s Fly Shop in Lake City, said conditions on the Lake Fork don’t look as bad as they did in 2002 thus far. Even back then, it wasn’t too hard on business.

“You just worked around it,” said Hall, who’s fished in the Gunnison Valley for 52 years. “Now my guides all make sure they have (thermometers) with them all the time.”

Flows on the Lake Fork reached as low as 44 cubic feet per second (cfs) in 2002. In the past month, 116 cfs is the low mark at the Gateview survey site.

While Blue Mesa Reservoir is also seeing lower water levels due to drought conditions, Weekend Warriors Outdoors owner Ryan Johnson said that warmer temperatures have not had an impact on fish.

“We’re still by far the largest reservoir in the state, even when we’re down by 40 feet,” said Johnson. “It seems like the kokanee population has started to rebound and last year was the best in four or five years.”

According to the National Climactic Data Center, most of Gunnison County was listed as seeing “extreme drought” conditions throughout late June and early July.

Lifting the voluntary closure of Tomichi Creek will be dependent on water temperatures dropping in the coming weeks. While recent rains have helped the cause, the coming weeks will be the real testing grounds for trout.

“In 2002, July was the time period where we saw the highest (water) temperatures,” said Brauch. “We don’t expect to see things get to that level, but we are monitoring conditions and will continue to.”  


(Matt Smith can be contacted at 970.641.1414 or mattsmith@gunnisontimes.com)