The Big Wood River basin has almost as much snow as in 2006 and 2017 – two years that saw significant flooding. Now, Blaine County is preparing for the possibility of another historic year.
The development of the Wood River Valley communities right up to the riverbed means about half of the Big Wood is unable to spread out to its natural floodplain. Kristine Hilt, the floodplain manager for Blaine County, said that’s part of what puts the area at risk.
"A river needs to migrate and be dynamic and when it can't be and it's channelized and straightened out, it actually is more erosive and the velocities of those floodwaters actually speed up," she said,
In 2017, flooding in Hailey kept some people out of their homes for weeks to months. Hilt said the outlook this year depends a lot on how fast the snow melts.
The county is holding three meetings this week to help people understand the risk, and what to do to prepare — from acquiring sandbags to following evacuation protocols. Hilt encouraged people to check whether they're in the 100-year floodplain established by FEMA. But, she said that title can be misleading.
“I did the math and we're averaging a huge flood of record typically every 9.25 years," she said.
Additionally, the floodplain maps are not perfect; flood waters crept past the boundaries in 2017. And, the current FEMA map for Blaine County is from 2010. The federal agency is working on a new map that shows updated risks, but that won't be certified for another few years.
Blaine County flood prep meetings
- April 18, 6 p.m., Ketchum City Hall
- April 19, 7 p.m., Hailey Community Campus
- April 20, 7 p.m., Carey City Hall
City of Hailey flood prep meetings
- April 19, 5:30 p.m., Hailey City Hall
- May 3, 5:30 p.m., Hailey City Hall
- Virtual option for both meetings: https://meet.goto.com/507079749
Find reporter Rachel Cohen on Twitter @racheld_cohen
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