River goes down, flooding continues
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| Spring Valley's Barto's Landing is underwater as the cresting Illinois River flows by below the Route 89 bridge. The river crested in Spring Valley in the early morning hours of Tuesday, but snow in the northern part of the state could keep river levels high when it begins to melt. (BCR photo/Barb Kromphardt) |
According to a flood statement issued Wednesday morning from the National Weather Service Chicago/Romeoville, the flood warning continues for the Illinois River as it flows through Bureau and LaSalle counties.
In LaSalle, the Illinois River crested at 29.03 feet at 10 p.m. Monday, and the water level was most recently observed at 26.67 feet at 10:30 a.m. Wednesday.
According to the report, minor flooding was still occurring and continued to be in the forecast. Minor flooding means minimal or no property damage but possibly some public threat or inconvenience.
The flood stage at LaSalle is 20.0 feet, and the river is not estimated to drop to 20.0 feet until Feb. 27.
The river hit its historical crest at LaSalle on Dec. 5, 1982, when the water hit 32.05 feet. The most recent high water mark was reached on Feb. 23, 1997, when the level hit 30.83 feet.
Downstream in Henry, the Illinois River crested at 6 a.m. Wednesday at 25.88 feet. It is estimated to remain near that level until the early morning hours of Friday, when the waters should begin to recede.
The flood stage at Henry is 23.0 feet, and the river is expected to stay above that level for the foreseeable future.
The river hit its historical crest at Henry on March 22, 1979, when the water hit 32.67 feet. The most recent high water mark was reached on March 2, 1997, when the level hit 30.56 feet.
Bill Morris, a hydrologist at the National Weather Service office at Romeoville (Chicago), said the recent flooding is a result of recent rainfall and snow melt.
In addition, Morris said rivers were already high from the usually high amount of rain received in early January.
“The rivers hadn’t fully recovered,” he said.
Morris said another factor causing problems is that, due to the cold weather, there are ice jams on some of the tributaries, including the lower Fox River near Ottawa.
Morris said the Illinois River is slowly falling, but there is still a lot of moisture in the form of rain frozen in area fields that will eventually melt.
Another factor impacting future river levels is the amount of snow on the ground. Morris said there is significant snow pack in northern Illinois, up to five inches.
“It’s not just the depth, but how much water is locked up in the snow pack,” he said. “We estimate about 2.5 inches.”
The NWS will issue its first spring flood outlook on Friday, based on current conditions and the long-term weather outlook. The report will be available on the NWS Web site at www.crh.noaa.gov.
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