River Diversion Will Eliminate Portaging

A river project, partially funded by the CWCB on the Arkansas River at Granite. The project was removing a river-wide diversion structure and replacing it with a new diversion structure that will allow unimpeded boating through Granite. Photo credit: Brent Gardner-Smith/Aspen Journalism

From The Chaffee County Times (Max R. Smith) via The Leadville Herald:

In the mid-1960s, a partnership between the cities of Colorado Springs and Aurora installed a diversion dam in the Arkansas River south of Granite near Clear Creek Reservoir as part of a pipeline system bringing water from the western slope of the Continental Divide to the Front Range.

The presence of the diversion dam caused that portion of the river to be non-navigable, requiring portaging of one’s raft or kayak.

By the end of this year, however, Colorado Springs Utilities is on schedule to complete a three-year project to build a new river diversion that will allow boaters to float right through, meaning that the 2020 rafting season will be the first in over 50 years in which the entirety of the Arkansas can be traveled without portage.

“We’ll see how the snow treats us over the next couple weeks, but we’re really down to some final boulder work in the river and general site cleanup at this point,” said CSU project manager Brian McCormick.

The intake that pumped water out of the Arkansas (which, legally speaking, comes from the Eagle River Basin as part of the Homestake Project), destined for Aurora and Colorado Springs, “as with anything in the river for 50-plus years, it took some wear and tear,” McCormick said. “By about the mid-2000s, the cities recognized we needed to rehabilitate this structure to keep it as a reliable facility and ensure safety of the river users.”

Construction on the new $9.1 million diversion project began in 2016 after a number of years of planning, budgeting, and engineering. Support for the project included $1.2 million in grant funding from the Arkansas Headwaters Recreation Area, Colorado Parks and Wildlife and the Colorado Water Conservation Board…

Significant to water consumers in Colorado Springs and Aurora, the project utilizes a new intake and piping structure to send water to the Otero pump station, he said.

Significant to boaters is a chute constructed of boulders and mortar with six two-foot drops that will allow them to pass the intake facility without exiting the river. McCormick said that CSU put the call out to members of Colorado’s river recreation community to participate in a trial run down the chute in November, testing the Arkansas’s newest whitewater feature…

Significant to the scaled, Omega-3 rich denizens of the Arkansas who swim upstream to spawn every year, the new diversion also features a fish ladder: a sequence of weirs and pools that give brown and rainbow trout a route to move up the river to their spawning grounds.