A rainy week in Summit County may bring on the flooding local officials have been waiting for and trying to avoid.
In the wake of a week of thunderstorms, Denver Water is preparing to release enough water from Dillon Reservoir downstream today to overflow the banks of the Blue River in Silverthorne.
“With all the rain we've been having it's causing some extra problems,” assistant county manager Thad Noll said. “It also causes snow to melt faster. That's the double whammy of rain.”
Denver Water has kept reservoir levels low all season, anticipating high runoff levels after record snowfall last winter, but heavy rain this week has increased inflows to the lake, raising water levels and leaving Denver Water and Silverthorne with a tough choice: release slightly more water than the Blue River can handle now and buy some time keeping the reservoir levels as low as possible, or keep controlling the outflow from the lake and be faced with a lot more water coming downstream when the reservoir finally fills.
The Blue River, downstream from the dam, can officially handle about 1,800 cubic feet of water per second (cfs). But current inflows to the reservoir are exceeding 2,400 cfs and once the reservoir fills completely, that is exactly how much water will have to be released downstream.
“Once the reservoir fills, then water in equals water out,” Noll said. “So sometimes raising (outflows) a little higher than 1,800 might be the better option.”
To keep reservoir levels as low as possible and put off the reality of so much water flooding the Blue River in the coming weeks, Denver Water expects to increase outflows to 1,900 cfs today.
“If (they) don't raise it, Silverthorne could have a problem later on,” Noll said.
Citizens and businesses in Silverthorne, particularly those along the Blue River should be prepared, officials stated in a Friday-night release, for high water over the next few weeks.
Denver Water has taken similar precautionary measures before, raising outflows as high as 1,902 cfs in 1995 when inflows peaked at more than 3,400 cfs.
