The whitewater boating season on the Lower Dolores River below McPhee dam is ending, but it may be briefly revived later.
By midnight May 23, flows will ramp down to 600 cubic feet per second, hold for 24 hours, then drop to 400 cfs after midnight on May 24. From there the river will drop to 200 cfs, then 75 cfs by Sunday May 28.
“Spring runoff forecasts have steadily dropped with the drier-than-normal weather,” said Ken Curtis, an engineer with the Dolores Water Conservancy District. “It is time to fill the reservoir.”
Curtis said there is a chance that early hot June weather could bring down the remaining snowpack very quickly, which could force a mini whitewater spill of boatable flows for four to six days in June.
“We’re watching for those conditions that could trigger some excess water,” for boating, he said.
A solid winter snowpack allowed for the reservoir to fill for farmers and provide for 52 days of whitewater boating below the dam. In mid-May, 4,000 cfs of flushing flows were released for 72 hours to benefit river ecology, including sediment clearing and channel scouring, which improves native fish habitat. There were seven days of optimal flow releases of around 2,000 cfs.
A year-in-review meeting is being planned by reservoir managers, boaters, and environmental groups to evaluate the season.
A plan by Colorado Parks and Wildlife to flush out small-mouth bass opens up a slight window for kayakable flows later in the summer.
In mid July, biologists want to use part of their reserved fish pool in McPhee reservoir to release 400 cfs for 3-4 days and disrupt the bass spawn. The bass are a threat to the flannelmouth and bluehead suckers and roundtail chub, preying on their young and competing for food sources.
“It would be delivered when male bass are guarding the fry on the nest and has the potential to hammer a major threat to native fish,” said Jim White, a parks and wildlife biologist.