Flooding

Rick Strack / Boise State Public Radio

A slow-moving weather system in south-central Idaho that the National Weather Service is calling a 100-year storm dumped nearly 3 inches of rain on Twin Falls and caused widespread flooding.

Twin Falls City Manager Travis Rothweiler tells The Times-News that the city's drainage system on Wednesday became overwhelmed, causing flooded streets, homes and businesses.

Rothweiler says sewage backed up into seven homes in the city, and that state and federal agencies have been notified.

Tom Kelly / Flickr

Forecasters with the National Weather Service say storms will move into southern and central Idaho this afternoon. Some of the storms could produce heavy rain and flash flooding.

The system is a surge of monsoonal moisture approaching Idaho from the south. NWS Meteorologist Les Colin says an inch of rain could fall in some areas.

historic photo, Cottonwood creek
Idaho Statesman, Boise Public Library

Since the devastating landslide hit the town of Oso, Wash. last month, people who live near hill slopes or mountainsides have been asking if something similar could happen to them. Though Boise has not seen the tragic loss of life the Oso slide brought, the city is no stranger to floods and mudslides near its foothills.

The Idaho Statesman / The Idaho Statesman/Boise Public Library

It was August, 1959. Boise was having one of its typical hot, dry summers. A fire had just burned 9,000 acres in the nearby foothills. Then on August 20, a huge storm system dumped heavy rain on the Treasure Valley. One inch of rain fell in an hour on the burn scar. 

The water overwhelmed the hills and washed away tons of topsoil. A Forest Service video made several years after the event, tells the story.

About 1,400 flood insurance policies in Idaho subsidized by the government are facing hefty premium increases despite a congressional fix intended to limit the worse of the rate hikes.

More than a million policyholders across the nation will be required to pay higher annual premiums as the federal government cuts subsidies in an effort to cover the National Flood Insurance Program's more than $24 billion deficit brought about by the discounts and a series of catastrophic storms.

National Weather Service

What a difference a week makes.

Last week, concern was mounting over how little precipitation had fallen in southern Idaho this winter. Now, forecasters say areas in southwestern Idaho and southeastern Oregon could see several days of flooding.

Mel Meier / InciWeb

The Beaver Creek Fire burned more than 174 square miles and endangered the towns of Hailey, Ketchum and Sun Valley last month. The once-enormous blaze is fully contained.

But residents in the area now have to be on alert for another danger: flash floods and mudslides over the charred land. The Times-News reports that 18 inches of mud came into the Croy Creek Canyon area overnight.

National Weather Service warned Idaho residents traveling or recreating on National Forest lands to be wary of possible flash flooding, as recent wildfires have scorched what ordinarily would have been rain-sopping vegetation from hillsides.

A flash flood watch goes into effect at midnight and continues through Tuesday on Boise National Forest areas burned by the massive Elk, Pony and Little Queens fires.

Kari Greer / Boise National Forest

Heavy rain prompted flash flood warnings Tuesday for areas affected by this summer’s wildfires in parts of Boise and Elmore counties.  The National Weather Service was concerned that barren terrain left after the Springs Creek and Trinity Ridge fires could produce debris and rock slides.

National Weather Service Hydrologist Troy Lindquist says the first substantial rain in months was expected to total about an inch and a half.  That’s not a lot, but he says it is enough to make things dangerous near the so-called “burn scars”.

Spring Weather Makes For Tricky River Management

May 9, 2012
Sadie Babits / Boise State Public Radio

Warmer temperatures this week have kept river levels high in Idaho as mountain snow melts. It’s been a challenging year for those who manage the state’s river systems. That’s because the spring runoff happened a month earlier than last year. It's brought flooding along the Boise River and raises questions about water availability next year. Just ask Ron Abramovich. He's a hydrologist and water supply specialist with the Natural Resources Conservation Service in Boise. 

Tim Merrick / US Geological Survey

 

The Boise River is under a flood warning for the next several days.   Dave Groenert  is a meteorologist with the National Weather Service in Boise. He says that warning will remain at least for the next seven days as temperatures rise. “They (temperatures ) look to peak at the middle of next week Wednesday,” explains Groenert. “And then after that cool back to normal.”