To look at the rocky shores currently flanking Ruedi Reservoir, it’s hard to fathom that within a month the banks will disappear and water could potentially spill over the 285-foot high dam.
Just 65 percent of its total 102,369-acre-foot capacity was filled as of Tuesday, as the hardy and stubborn Fryingpan River Valley snowpack that feeds Ruedi is finally starting to lose its icy grip. According to Tim Miller, a hydrologist for the U.S. Bureau of Reclamation who is part of the team that manages Ruedi, 14 miles east of Basalt, efforts heretofore this season have been to mitigate the reservoir’s rise in anticipation of what’s to come.
Miller said the fill date is expected around the first week of July.
“We’re in normal spring operations for high snowpack,” Miller said. Snotel (“snow telemetry”) measurement sites, including those at Ivanhoe, which sits at 10,400 feet, Independence Pass, Fremont, Kiln and Bromley, on June 4 showed moisture that’s about four times the median for this date, he pointed out.
The snow water equivalent – which is about 3 inches per foot of snow – is around 11.5 inches at present, he said, noting the median is around 3 inches of SWE for early June.
“At June 1st we have about the same amount of snow as we’d have on April 1,” said Miller, who is based out of Loveland, Colo.
In his 37 years as general manager of the Colorado River Water Conservation District, Eric Kuhn said he can only recall one possible spillover of the dam, which was completed in 1968.
“They may have had a spill in 1995,” Kuhn said this week. “And this year looks a lot like 1995.”
Now retired, but still providing institutional history on local water issues (Kuhn has penned a book for University of Arizona press, Science be Dammed, that will be released in November), he recalled that in 1995 there was a brief period when the water levels exceeded 1,000 cubic feet per second. That year, Ruedi’s peak came the second week of July; a “big event” rainstorm that week also contributed to flooding in the Seven Castles area.
While the snowpack was deeper in 2011 than this year, its peak on July 2 of around 900 cfs didn’t result in any spillover, he said. Data wasn’t collected back in 1983, which was another huge snow year, Kuhn added.
Both water managers said that Ruedi’s operations can’t be regarded in isolation. It’s raison d’être remains as a place for storage and releases, including diversions intended for Eastern Slope needs via the Boustead Tunnel. A maximum of 945 cfs can be diverted to Boustead, after which time there will be the need to release more water downstream. That was the case back in 2011, another huge snow year of 2011.
“Ruedi wasn’t designed as a flood control reservoir,” Kuhn said. “There’s an expectation some folks have that it’s supposed to be operated for flood control and it’s not.”
According to Miller, “We don’t have a mandate to provide downstream protection for releases. Our number one priority is to fill the reservoir for the summer.”
“The lake from this point forward will rise. It will be good for surface water recreation,” Miller said. Below the reservoir, the Fryingpan River may rise to 300 cfs until early or mid-July, he added. Fishers are asked to be patient
A best-case scenario for Ruedi would be continued cool temperatures and not a lot of precipitation.
“A snow melt that doesn’t cause crazy things to happen would be a better scenario,” according to Miller.
About one month out from when Ruedi is anticipated to fill and possibly spill, those who may be potentially impacted by higher flows downstream of the reservoir are advised to start thinking about what precautions may be necessary.
“You may not need them, but you may need them,” Miller said.