Ruedi Reservoir fills but flooding averted in Basalt
BASALT – Ruedi Reservoir filled to capacity Thursday and water flowed through the dam’s spillway, but the Bureau of Reclamation adjusted releases to stay below a level that would cause flooding on the lower Fryingpan River.
Ruedi was considered “full” at about 10 a.m. Thursday, and water started going through the spillway about two hours later, said Kara Lamb, public information specialist with the reclamation bureau. But releases from the Ruedi outlet infrastructure and the power plant at the dam were lowered to keep flows at about the same level as before the reservoir filled, she said.
About 750 cubic feet of water per second was being released from Ruedi. Approximately 50 cfs was flowing from Rocky Fork Creek, just below the dam, for a combined flow of 800 cfs.
“850 is where people start to get their property wet,” Lamb said.
The reclamation bureau sent a warning at 11:30 p.m. Wednesday that made it sound like higher releases were inevitable once the reservoir filled.
“When Ruedi hits full, we will begin bypassing the native inflow,” the notice said. In other words, the release would have to equal the inflow.
That set off an alarm for Basalt Town Manager Bill Kane because inflows have been at 1,200 cfs recently.
Emergency response agencies from Basalt and Pitkin and Eagle counties met at 11 a.m. Thursday to consider if any flood preparations were necessary. They held a telephone conference call with Bureau of Reclamation officials and were surprised to learn the releases wouldn’t match inflows. “Full,” it seems, doesn’t really mean “full” at Ruedi. There is a higher capacity for the reservoir – beyond what is considered the operationally full level – that can be used by adjusting releases, Andrew Gilmore, a hydrologist with the reclamation bureau, told Roaring Fork Valley officials.
“It sounds like we do have a buffer here,” Kane said after the meeting.
Lamb explained after the meeting that using the spillway and adjusting the other outlets allowed the reclamation bureau to avoid matching the inflow.
“We’re able to slow it enough that it’s not a straight tradeoff,” she said.
Gilmore said high water releases will likely be required into Friday. After that, signs point to a lower level of runoff. Much lower temperatures are expected starting Friday night and through the weekend. In addition, officials said the high temperatures over the last week have melted a significant portion of the snowpack, even at high elevations.
“This can’t continue much longer,” Gilmore said.
Kane said a reliable rule of thumb for him over the years has been that peak runoff has passed once all visible snow is gone from Bell Mountain on the Aspen Mountain ski area. The snow on Bell disappeared Wednesday, he said.
Gilmore said the reclamation bureau wants the flexibility to boost total releases from Ruedi and Rocky Fork to 850 cfs, if local officials thought that could be done without causing flooding damage. Local officials responded that seemed possible, at least during daylight hours, when the Roaring Fork River’s flow has generally been lower than at night. No major releases are expected from reservoirs in the upper Roaring Fork River drainage for the next week.
“I have no doubt we could go up to 850 [on the Fryingpan] without much difference,” Kane said after Thursday’s meeting.
The higher water has remained within the riverbanks of the Fryingpan and Roaring Fork, although some low-lying areas are swamped with groundwater seepage, said Basalt police Sgt. Stu Curry, incident commander for a flood preparedness team. “Our team and officials from the Bureau of Reclamation are watching reservoir, spillway and river flows 24/7,” he said.
A flood preparedness hotline has been activated at 429-1800.