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Troubled Waters: Flood Season Looms

FEMA: Only 1.4 percent of Idahoans have flood insurance

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We have been spoiled.

December's blast of snow left Idaho's ski resorts knee-deep in white gold. January dried up roadways, leaving a driver-friendly journey to the slopes. In the Treasure Valley, record high temperatures in the 60s tempted us to consider short-sleeve shirts.

That's all over now. But don't take our word for it. Consider the meteorologists. Not the weather boys on the 10 p.m. news. While Rick, Vin and Scott are checking their hair and make-up, the men and women at the Boise office of the National Weather Service are studying jet streams and radar and satellite imageries. While Larry's seven-day forecast is something "where your weekend is always in view," the scientists at the NWS are poring over an outlook for the next 60 days.

"Let me show you what's going on," said Jay Breidenbach, rolling his chair to one of the nearly dozen monitors at the official Boise weather center. Breidenbach is senior hydrologist at the NWS, which means he's the go-to guy for all things water--snow and ice and just about every other weather event. Breidenbach pointed to a techni-color map of equatorial sea surface temperatures from half a world away.

"Look at this blue infrared reading at the equator," said Breidenbach. "This is definitely an anomaly. Look at how cool the equatorial waters have become. Add that to the fact that we're in a La Nina year, and we can expect a much colder, much wetter weather pattern."

Even the most casual viewer of the Weather Channel knows something about La Nina, the mysterious climatological condition occurring every five to seven years.

"In La Nina, a high pressure system blocks the polar jet stream, allowing the Pacific jet stream to scoop up the West Coast of North America," said Breidenbach. "It pile drives the Pacific Northwest with big storms like we had this past Christmas. It alternates with a pattern that brings in bitterly cold air down from Canada. So average that over a whole season, and you'll get below-normal temperatures and above-normal precipitation."

Translation? There's a good chance that Idaho's snowpack will increase significantly during the next 30 to 60 days. Good news for the ski resorts. Scary news if you live anywhere near a river.

"We just met with the weather service," said Payette County Sheriff Chad Huff. "We've got a pretty good game plan in case of flood. The technology is so much better than it was in 1997."

Huff and his colleagues remember 1997 well: A record-breaking 14.5 feet of water filled the Payette River.

"It cascaded over the river banks," said Capt. Toby Hauntz of the Payette County Sheriff's Department. "It filled the streets. Downtown Payette was flooded."

If 1997 is too far back for some to remember, Huff and Hauntz want Idahoans to recall June 2010.

"Technically, it was labeled a moderate flood," said Hauntz. "But it was the third-highest on record. The Payette peaked at 13.69 feet. It had great potential to be disastrous."

The Payette Sheriff's Department will have a new gizmo at its disposal this flood season.

"We have four new sandbag machines," said Huff. "They can fill 800 bags an hour." Huff estimated one house near the river could easily require 3,000 to 4,000 sandbags.

In Breidenbach's just-released water supply forecast, the Payette River, and nearly every tributary in Idaho, is running at or above a 30-year average. The Boise River, for instance, is forecast to run 102 percent of average through the spring.

Heightened danger for flooding due to cresting rivers can, of course, lead to devastating damage. However, a recent report from the Federal Emergency Management System indicated that Idaho is poorly prepared. FEMA's National Flood Insurance Program reports that only 1.4 percent of Idaho's households are covered by flood insurance. The policies typically take 30 days to become effective. FEMA has launched floodsmart.gov as a clearinghouse for flood preparation.

"We certainly see the river levels as an issue. And we're keeping a close eye on the La Nina pattern, but let me show you something else," said Breidenbach.

He next accessed an imagery map of Idaho snowpacks.

"You'll remember that we had blizzard conditions in some parts of Idaho around the holidays, at Thanksgiving and again between Christmas and New Year's Day," said Breidenbach. "That dropped a ton of snow in the mountains. What's very important is that high elevations have gained considerable snow-water equivalent. It's not the depth of the snow that matters, but rather how much water would be in that snow if you melted it down. So, as the storms roll in over the next couple of months, precipitation is added to the existing snow, and the snow-water equivalent grows. When it begins to melt and run off, it's a growing factor in possible flooding."

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