From Aspen Journalism (Brent Gardner-Smith) via The Aspen Times:
A consulting engineer and whitewater park designer has raised concerns that three whitewater parks proposed by the City of Glenwood Springs between Grizzly Creek and Two Rivers Park on the Colorado River could make the popular stretch of river too gnarly for some boaters and floaters.
“Changing the nature of the reach by creating a recreational in-channel diversion (RICD) to entice expert recreational experiences would be inappropriate and would likely have deleterious effects on existing recreational experiences … ,” concluded Jason Carey, an engineer with River Restoration of Carbondale, in a Sept. 9 report.
Carey designed the popular surf wave on the Colorado River in West Glenwood Springs, as well as a whitewater park now under construction on the Colorado at Pumphouse, which is below Gore Canyon and above State Bridge.
The Glenwood Springs Hot Springs Lodge & Pool is concerned about potential damage to its source of hot water by the installation of wave-producing “control structures” in one of the parks, and so it hired Carey to study a preliminary engineering report prepared in January for the city by another whitewater park designer, Scott Shipley of S2O Design & Engineering.
On Friday, Shipley responded to Carey’s independent technical review of his design with a supplemental engineering report of his own.
“It is the intent of the city of Glenwood Springs to create whitewater parks at the proposed sites that will produce a surfing and boating attraction for all types of visitors while protecting the existing floating and rafting experiences through this reach,” Shipley wrote in his Dec. 5 report.
The key, Shipley says, is to provide a way for boaters to get around the two man-made waves in each of the three parks, if they want to.
“The proposed RICD control structures will utilize clearly marked bypass chutes that are designed to provide a route that is easily recognizable and navigable with low to medium size waves, which provides for a concurrent ‘less difficult’ recreational experience,” Shipley wrote, adding that “the proposed structures will not change the difficulty rating of the reach.”
But Carey’s review of Shipley’s design suggested that a wave big enough to attract expert kayakers may also produce river carnage amongst casual boaters, even with a bypass channel.
“A recently completed RICD in Durango is notorious for flipping rafts, even with the bypass boat chute’s obvious routes of navigation designed into the structures,” Carey wrote. “One user commented how they just got off of the Grand Canyon and never flipped. First run down the Durango RICD and they flipped in their raft and lost equipment.”
While Carey does not say so, Shipley of S20 designed the new whitewater park that opened this spring in Durango on Smelter Rapid in the Animas River.
“This type of experience may be acceptable as Durango was a Class III reach modified into a Class III+ RICD and people know there is a risk of flipping and self rescue in these rapids,” Carey wrote. “However flipping rafts may be unacceptable in Class II rapids when children, elderly or otherwise risk adverse persons are aboard.”
The section of the Colorado between Grizzly Creek and Two Rivers is considered Class III during bigger water, but for most of the summer the stretch is rated Class II, as the river typically runs at a consistent 1,250 cfs due to the senior water rights tied to the Shoshone hydropower plant upstream.
The surf wave in West Glenwood, which was designed by Carey, has a bypass channel, but it also has flipped rafts. Carey notes, however, that the big wave is located on a run – Two Rivers through South Canyon – that was already a consistent Class III stretch and so the “Glenwood wave” did not change the nature of the run.
The city is seeking a new water right in Div. 5 Water Court for the whitewater parks, which are proposed for three locations along 3.5 river miles of the Colorado River.
The parks, each with two wave-producing structures, are proposed at No Name and Horseshoe Bend, which are both upstream of downtown Glenwood, and at upper Two Rivers Park, which is just above the confluence with the Roaring Fork River.
The city wants the right to call for 1,250 cfs of water from April 1 to Sept. 30, for 2,500 cfs for up to 46 days between April 30 and July 23, and for 4,000 cfs for up to five days between May 11 and July 6.
Additional comments on the city’s proposal are due in to water court by March.
Aspen Journalism and The Aspen Times are collaborating on coverage of rivers and water. More at http://www.aspenjournalism.org.
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