As a community restitution crew worked Monday to clear up the debris littering the Fox River shoreline north of the St. Charles Municipal Center, city officials were at work putting together a report to members of the City Council about last week’s flooding.
Heavy rains pushed the Fox River well past flood stage on Thursday as the rising water overflowed its banks, flooding parking lots, homes and even spilling onto city streets.
St. Charles Public Works Director Mark Koenen told the St. Charles City Council Government Services Committee that the river’s water levels were so high, it as backing up out of the storm sewers and onto Route 31 just north of Main Street on Thursday. At one point early that evening, he said, water on the pavement was 6 to 8 inches deep. Route 31 was kept open, he said, but the traffic moved very slowly through the flood.
He pointed to Route 31 to illustrate just how high the river had risen. The storm sewers there flow by gravity into the river, he said. That they had backed up was an indication that the water levels in the river were as high as that 6 to 8 inches of water pooling on that short stretch of Route 31.
But the flooding in St. Charles was far more widespread, affecting local creeks on the East Side of town as well as the Fox River. Koenen said rainfall in St. Charles measured 4 inches last Thursday, although there were hot spots that received more, and some areas that received less.
Regardless, it was a lot of rain, and it swelled the Fox River significantly.
Koenen said the city uses river flow data collected in Algonquin, which is upstream, to learn what’s moving toward St. Charles. The data, he said, is telling.
“We watched the Algonquin elevation peak at Algonquin (Monday) …. it was the 10th or 11th highest value in the last 90 years,” he told aldermen. At its high point, the Algonquin measurement hit 4.5 feet over flood stage, he said. Monday morning, the river still measured 3.9 feet over flood stage.
He presented aldermen with a series of slides showing the flooding as he recorded it around town on Thursday, and the images were daunting.
Lakes in fields or covering intersections, a stream that disappeared because the floodwaters rose so high, a seeming river of water cascading over Tyler Road, eventually washing away a stone wall whose remnants now lie somewhere in the detention area it bordered. He also showed photos of flooding along 7th Avenue Creek and Illinois Avenue.
Bridge Still Closed; Assessment Begins
Koenen said the city tried to inspect the Illinois Street Bridge on Monday, but one of the bridge’s piers remains underwater, out of the view of an inspection, so the bridge remains closed. The city will send out an inspector again Tuesday. If the bridge is deemed safe after being exposed to such high water levels, it may reopen.
Even as efforts are getting under way to clean up debris — and the city is working with it’s waste-hauling contractor to set up a flood-debris collection program — Koenen said the city is continuing to assess the flooding to determine steps that should be considered down the road to head off or minimize future recurrences.
One step already being pursued is to persuade the Federal Emergency Management Agency, or FEMA, to re-evaluate its flood insurance study for the area along 7th Avenue in St. Charles. Some of the federal agency’s maps show flood channels that are far narrower than what the city witnessed last week.
It’s an important consideration — how FEMA’s flood maps are drawn can determine whether flood insurance will be required as a condition for a mortgage, and they can trigger a 25 percent reduction in flood insurance rates for some homeowners, he said.
The work could be extensive. If FEMA agrees to update its information, that ill include a process in which “feasible improvements” needed to reduce the impact of future flooding will have to be considered by the city. That will be problematic along 7th Avenue Creek, Koenen said, where most of the property is privately owned. The city will have to work with landowners to effect change in that area, he said.
Koenen also remarked that city crews’ efforts from time to time go through stream beds to clear debris with the intent of minimizing the potential for flooding seemed to have been helpful in this round of floods. Those efforts will continue.
Let Patch save you time. Our free newsletter can be delivered to your inbox. Fast signup here.