Summit County braces for higher risk of flooding during runoff
April 20, 2014
If you live in a part of Summit County prone to floods, you might want to call your insurance company.
That’s advice from county assistant manager Thad Noll, who says the risk of flooding during runoff season this year will be higher than usual.
Most companies won’t cover damage unless clients have a policy 30 days before a flood. If you need flood insurance and your company won’t cover you, Noll said, you can always use FEMA’s national flood insurance program.
Flood risk is higher because the snowpack near Dillon Reservoir this year is about 35 percent above average, Denver Water spokeswoman Stacy Chesney said.
Comparing snowpack data from the Natural Resources Conservation Service, Noll said Friday’s numbers look just like they did on the same date in 2011, the year with the most snowpack on record.
The data also look similar to 1996, he said, a year when rapid snowmelt combined with a giant rainstorm to flood neighborhoods all over Summit County.
“That was a nasty runoff,” he said.
When Noll lived in Blue River that year, he said, he was shocked by the amount of water in streets, septic fields and basements. Parts of Silverthorne, Keystone and Summit Cove flooded, and Coyne Valley Road in Breckenridge washed out, he said.
“It was terrible,” he said. “It was a mess.”
To prepare, local water managers are meeting with Denver Water.
The utility, which provides West Slope water to the Denver metro area, regulates how much water comes out of Dillon Reservoir. The utility’s employees monitor Summit’s snowpack conditions, weather forecasts and the reservoir’s natural inflows and outflows.
This week, Denver Water increased the outflow to the Blue River. The increase, from 500 cubic feet per second to 600 cfs over Monday and Tuesday, was the fifth this season beginning in early March.
Though the utility isn’t legally required to do so, it lowers the reservoir’s level in years with high snowpack to lessen the risk of flooding north of Dillon Dam.
Denver Water can’t control flooding around the reservoir, but it can help Silverthorne, which faces the greatest risk.
The town will see problems if the reservoir outflow reaches 1,800 cfs, or triple what it is now, Noll said. That’s when the river will touch Silverthorne’s Sixth Street bridge.
Silverthorne’s public works director, Bill Linfield, said the bike trail under Bald Eagle Road is already closed because it’s under water.
Locally, water managers have one preventive technique they’re using now.
County and town employees, usually snowplow drivers, check and clear any clogged culverts, or underground water pipes. They shovel debris, pull sticks out by hand and use a steamer if ice is a problem.
Since 1996, government staff enlarged culverts and changed drainage patterns to prevent damage.
Denver Water’s primary goal is keeping the reservoir full for its water supply, which makes managers at the Dillon and Frisco marinas happy. A full reservoir means more boat rentals and slip sales.
In high runoff seasons, the utility lets water out of the reservoir until the end of June.
“Ideally the reservoir is full for the Fourth of July, and there’s no flooding,” Noll said. “Yay. Everybody’s happy.”
He said going forward residents can expect more public announcements and free sandbags.
To find out if your home is at risk, contact your local town government or Summit County officials or go to the FEMA Map Service Center.
For more information, visit https://www.floodsmart.gov.