From The Durango Herald (Mary Shinn):
Whitewater advocates have anecdotally noticed more fishermen near whitewater rapids, and they are working on gathering data to show how the parks can benefit fish.
But Colorado Parks and Wildlife data show the parks degrade fish habitat and their ability to migrate upstream, said Jim White, a biologist with the department.
“Whitewater park features are not suitable fish habitat,” he said.
Human-made parks create fierce velocities that make it hard for fish to migrate over them. Fish must also battle a washing-machine effect in the human-made pools, he said.
The parks are also being built in or near towns, where whitewater rapids would be less likely to occur.
“By the time you get down to broader valleys … they are not typically natural features,” he said.
However, engineers and advocates – including Scott Shipley who designed the improvements to Smelter Rapid – argue whitewater parks can be built to improve fish habitat, and Colorado Parks and Wildlife is basing its conclusion on limited studies.
“As far as hard science goes, there is very little hard science on the issue,” said Shane Sigle, with Riverwise Engineering.
Despite the disagreement, proponents on both sides are interested in compromises that help protect fish. Some 30 whitewater parks are operating across the state, and they are boosting tourism and driving local economies, according to professionals in the field.
Smelter Rapid in Durango is an example of such a compromise. It was not quality-fish habitat to begin with, so it made sense to build permanent structures in that section, White said.
Colorado Parks and Wildlife also supported the Whitewater Park, saying construction of the permanent features secured a recreational-water right that helps protect fish from low flows, he said.
The city already was maintaining Smelter Rapid for whitewater features prior to construction of the park. The Army Corps of Engineers anticipates the grouted structures will limit the disturbance from continued maintenance, said Kara Hellige, senior project manager for the corps.
In addition, the corps requires the city to monitor the stability of the structures and banks, water quality and the movement of sediment after construction.
The monitoring required at Smelter Rapid and other parks should help engineers better understand how human-made rapids impact rivers.
More whitewater coverage here.