MORRIS – When the water stopped rising Thursday morning in Morris, preliminary results had the Illinois River topping out at 23.04 feet. If that number holds true, it would be the eighth highest crest on record.
These record or near-record crests have been occurring more frequently. Including the most recent, four of the top 10 highest recorded crests of the Illinois River in Morris have occurred in the past 10 years, with a fifth occurring in September of 2008.
There are another two recent crests in the top 20.
"If you look at the record, it definitely looks like there is more flooding," said Mike Phillips, a geology professor at Illinois Valley Community College in Oglesby.
Phillips has studied floods and flooding for 30 years and said the flood events are becoming more frequent for a number of reasons, some of which have been recognized for decades.
One is field tiling. As farmers lay tiling in their fields, often at a large expense in time and money, water stays in the field less.
The most common type of tiling is a pipe buried in the dirt with numerous holes on the outside. Water gets into the pipe, then is rushed down to the nearest exit in a stream or irrigation ditch.
"Farmers make fields more efficient and the water gets into streams and rivers more quickly," Phillips said. Instead of water sitting in fields naturally, filtering out slowly, the fields dry more quickly so the farmers can get to work in their fields.
It's not the only cause, however.
"Cities aren't off the hook," Phillips said.
While water running off of farmer's fields quicker and more efficiently is one factor, areas built up with buildings, parking lots and storm sewers are also increasing the flow of water from rain clouds to rivers.
The rivers don't flow naturally anymore, either. Locks and dams control the levels and pace of the water, while levees divert water from historical areas of flooding and push it further downstream.
These issues have been recognized by geologists for 50 or 60 years, Phillips said.
There's a new wrinkle, however: climate change on top of the physical changes.
"We've recognized the alteration of the landscape," he said. "Now we're seeing changes in weather patterns ... Rain seems to come in heavier downpours."
But while the last few years have seen heavier storms, it might be too early to attribute it to climate change.
"There's a big misconception of climate versus weather," said Andrew Krein, a meteorologist at the National Weather Service Office in Romeoville. "Climate in general is looking at really long term periods of weather data. Weather is part of climate, but individual weather events like these, you can't say that's part of climate."
He compared it to the concept of a 100-year flood: It doesn't mean a flood that size should only happen once a century, but rather that there is a 1% chance each year that a flood of that size would occur.
So the recent high-water marks for the Illinois River could just be bad luck and the region has been in the path of several large storms.
Krein also said that, while construction and urbanization plays a role, there hasn't been big urbanization along the Des Plaines or Kankakee Rivers, both of which flow into the Illinois River, in the past decade since the housing boom.
"It's luck of the draw, or bad luck of the draw," he said.
New construction, such as big box stores or housing developments, also have to have storm water retention ponds in most localities.
Changes to make
Phillips noted the way the city of Ottawa has handled its flooding issues along the river. It left areas prone to flooding to be parks and kept buildings and construction out of it.
"A swing set might get wet, but that's it," Phillips said.
He noted Morris is mostly the same, with the state park and green space along the river.
Long term, he said, "We could, and probably should, look to slow down the amount of carbon dioxide into the atmosphere."
The region is also served by the Illinois Valley Flood Resiliency Alliance, a group of local communities that shares information and resources along the Illinois River. The group was organized by State Sen. Sue Rezin, R-Morris, following the record 2013 flood.