A fast-moving rise in the Little Sioux River between 2 p.m. and midnight Wednesday has flooded and closed several area roads and streets in and around Cherokee.
The flooding caused major traffic congestion on U.S. 59 north in Cherokee and the Iowa Highway 3 By-Pass, as traffic was routed east around Cherokee on the By-Pass, south on the pavement east of the U.S. Highway 59 and Iowa Highway 3 By-Pass junction on the East Hill, and then back west on Linden Street to access south Cherokee businesses and homes, and U.S. Highway 59 south.
According to David Boothby of the Cherokee Flood Committee, the Little Sioux River was expected to crest sometimes late Thursday night and then slowly begin to recede.
Flood stage is 17 feet, and the crest was expected to hit 24 feet Thursday night. Much over 24 feet and the water inundates the Iowa Highway 3 By-Pass just east of the river bridge there, which would force drivers from the east to go north towards Larabbee to access U.S. Highway 59 into Cherokee and/or north.
When the Little Sioux River hits the 17-foot flood stage, minor lowland flooding begins and Cherokee County Rescue mobilizes and sets up the Flood Control Center.
At 18 feet, Wescott Park and surrounding park areas begin to flood as the river overflows its south banks in Cherokee. At 19 feet, the north banks overflow and water surges north of the river bridge and extends towards downtown, depending upon the water levels.
At 21 feet, East Main Street floods west of the river bridge and extends towards downtown depending upon water levels reached.
At 27 feet, dozens of homes and about 15 Cherokee businesses are flooded to various degrees.
Historical flood crests in Cherokee include the record 27.20 feet in April, 1965, and 27.08 in July, 1993.
The National Weather Service categorizes major flood stage at 24 feet or higher, moderate flood stage at 21 feet, flood stage at 17 feet, and action stage at 15 feet.
Also according to the NWS, the predicted 24-foot flood stage crest Thursday night could last into Saturday early morning before falling to 20 feet by Tuesday, pending no impacting rains or snowfall.
A rain/snow mix for Northwest Iowa was forecast at 70-percent for today, with snow accumulations of two inches projected.
Boothby said he has been measuring the flood stage at the South Second Street bridge every few hours the past few days.
"I've probably driven over a hundred miles since last night," laughed Boothby, referencing the lengthy drive around town to access the bridge flood gauge just a few blocks south of Cherokee's downtown.
Flooding woes also continued today to plague communities, homes and businesses along the Big Sioux and Floyd Rivers in Northwest Iowa, along with the Little Sioux River at Spencer and Linn Grove, and the Iowa Great Lakes area.
For more photos of the flooding, see the "Sprong Flood 2010: Photo Gallery.