Area braces for possible flooding
Published 9:30 am Friday, March 12, 2010
There was above-normal rainfall in the fall. There was above-normal snowfall this winter. As a result, the National Weather Service is expecting rising rivers this spring as the mercury rises.
Brett Behnke of the Shell Rock River Watershed District said snow and ice have plugged many culverts and underpasses. Meltwater in fields and drainage ditches is ponding.
“It’s just a matter of when those let loose,” he said.
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Even so, it’s been a good thaw so far. A fast thaw results in floods. Mild temperatures without the sun this week have caused melting but not too suddenly. Surprisingly, the rain, Behnke said, has been good for the situation. It has helped thaw the frosted ground somewhat, which in turn allows for moisture to soak into the soil instead of into lakes and streams.
But next week the forecast calls for sunshine and temperatures could reach the 50s. That, he said, could change the flood outlook and unplug drains big and little.
“We’ll see what happens. It will change a lot next week with 50-degree days,” Behnke said.
The National Weather Service observes waterways that regularly flood. At three miles northwest of Austin, Turtle Creek is expected to crest at 9.4 feet at 6 a.m. Saturday — not considered flood stage but it is in what’s called action stage. Flood stage is 10.5 feet. The Cedar River north and south of Austin also will reach action stage on Saturday morning. A flood warning is in effect for the Austin area.
The Winnebago River at Mason City, Iowa, will reach 10.7 feet on Sunday night, above the flood stage level of 7 feet. Mason City is bracing for flooding, and a flood warning is in effect.
The Albert Lea area mostly is at the start of rivers and creeks — Shell Rock, Blue Earth, Big Cobb, Le Sueur, Lime, Turtle.
The National Weather Service doesn’t display a gauge for the Shell Rock River until it reaches Shell Rock, Iowa, where it is expected to crest at 14 feet Sunday night. Flood stage is 12 feet. It was at 10.61 at noon Thursday. The record was 20.36 on June 10, 2008.
Albert Lea is at the start of the Shell Rock, and Glenville is the first city through which it flows. The city has a wide enough floodplain that it mostly avoids flood damage.
Mark Schumaker of Hillcrest Drive said since U.S. Highway 69 was raised more than a decade ago the waters have never covered the road. The flooding comes within a few yards of the highway but not over it.
He said a few homes on lower parts along River Road suffer flooding sometimes but most others are high enough.
Northwood, Iowa, is the next town on the Shell Rock. Its two city parks near the downtown flood regularly and the water comes close to businesses but usually the city stays safe.
No flooding is expected for monitored points on the Blue Earth River and Le Sueur River.
Still, the national hydrologic assessment places much of Minnesota, Iowa and the Dakotas at a high risk of flooding.
Manchester Township trustee Neal Gjersvik said Manchester Township’s motor grader operator has done a fine job of clearing snow in the winter, pushing it far enough into the ditches so it doesn’t melt out into the roads.
He said once the frost boils rise, township roads the area become problematic.
Many gravel roads in the area already are soft from the spring moisture but have enough of a crown remaining for runoff. And some county drainage ditches face spring erosion problems. A meeting Tuesday at the courthouse will address erosion on Ditch 11 near the Super America northwest of Albert Lea.