Friday, July 15, 2011

Silverthorne Flood Worries Subside

After a week of heavy rain and high water, inflows to the Dillon Reservoir are beginning to drop off to less alarming levels, Denver Water announced Thursday, allowing Silverthorne residents to breathe a sigh of relief.


“We've been fortunate not to experience any significant flooding problems in Silverthorne with the higher flows we've seen over the last week,” Silverthorne spokesman Ryan Hyland said in an email. “We are pleased to see the Dillon Reservoir inflows dropping and we're hopeful that we will soon see flows in the Blue coming down.”

Despite the decline in water levels, a National Weather Service flood advisory remains in effect on the Blue River in central Summit County through 1 p.m. today.

Denver Water officials reported water flowing into the reservoir dropped to just over 1,950 cubic feet of water per second (cfs) from the nearly 2,200 cubic feet per second dumping into the lake early this week.

The reservoir is now less than a foot from its capacity, and when it fills completely Denver Water will have to release as much water out of the reservoir as is flowing into it.

The utility company has kept outflows at just under 1,900 cfs — slightly more than the lower Blue River's 1,800 cfs capacity — this week in an attempt to avoid releasing heavier flows downstream when the reservoir fills.

With Thursday's waning inflows, it looks like they may have succeeded.

“If the inflow continues to decline, we should soon feel comfortable reducing the outflow to the Blue River,” Denver Water raw water supply manager Bob Steger said in an email Thursday.

But with scattered thunderstorms in the forecast through the weekend, the situation remains tentative for Silverthorne.

“Although Denver Water may soon be able to reduce the inflow into the Blue, the flows will still be fast and high for quite some time,” Hyland said.

Summit County is facing a 30 percent chance of afternoon showers and thunderstorms today, according to the National Weather Service, and the same forecast continues throughout the weekend, with rain possible between noon and midnight Saturday and Sunday. High temperatures could approach 80 degrees both days.

Dillon Reservoir isn't the only Colorado reservoir filling up quickly this year. Carter Lake, a Bureau of Reclamation reservoir near Berthoud, is also completely full ahead of schedule, and Horsetooth Reservoir west of Fort Collins is expected to reach capacity in less than two weeks, according to information reported by the Loveland Reporter Herald.

The two lakes are filling with Western Slope snow melt, carried east by a system of pipes, tunnels and rivers to Larimer County.

The lakes haven't been this full in seven years, according to the Reporter Herald.