In what some residents are calling the worst flooding they’ve seen in more than a decade, basements all over town took in inches to feet of water overnight on Sunday, May 17. The eastbound I-290 expressway was closed temporarily, as were sections of Desplaines and Harlem avenues.

Mayor Rory Hoskins said his own house got about 2 inches of water in the basement, and he acknowledged that was far less than many other people.

“We definitely don’t consider ourselves victims,” said Hoskins, who added that he’s been talking to mayors and leaders from other towns whose residents are going through the same thing. “It’s a small consolation that we’re all in this together,” he said.

Village Administrator Tim Gillian said this storm is “right up there” with other bad flooding suffered by the village. “Without a full analysis it’s hard to compare exactly,” he said, but a lot of people have been affected.

Susan Mangiaracina, who has lived in Forest Park for 26 years, said this is the very first time her house has flooded.

“I’ve never seen anything like it, with water just pouring into the house,” said Mangiaracina, who reported 6 inches in her basement. “We’d get occasional seepage, but nothing like this. It was bubbling up from the sewer and seeping in.”

She said she knows other residents got a lot more water in their homes, but it surprised her to get any at all after so many years. “Was there just too much water? Why this time?” she asked.

Businesses on Madison Street reported flooding too. Todd & Holland Tea took in at least 8 inches. Marty Sorice, who has owned businesses in town for 37 years, said he got water in the basement of one of his Madison Street establishments for the first time ever.

How much rain did Forest Park get?

How much water fell on the village and surrounding communities? As one village official put it: “We got a sh*t ton.”

For a more scientific answer, the Review reached out to Allison Fore, public and intergovernmental affairs officer of the Metropolitan Water Reclamation District (MWRD).

“Over the last 96 hours, the Chicago metropolitan area has seen between 6 to 8 inches of rainfall,” said Fore in an email on Monday. In the month of May, she added, “we have experienced unprecedented rain, and we are continuing to experience it at record levels.” For the entire month of May so far, 8.19 inches has fallen over the Chicago metropolitan area, almost as much already as the record 8.25 inches recorded for the entire month in 2019.

Where does the rainwater go?

The ground. The sewers. The river. The Deep Tunnel.

Fore explained that most sewer systems in the Chicago area were built over 100 years ago. Forest Park, she said, “operates with a combined sewer system, meaning it was originally designed to drain sanitary flow and a limited amount of stormwater directly to the waterways.” Sewer separation and installing wider water mains are projects the village has been undertaking over the past few years, but with so much rain coming down so quickly, it’s impossible for systems to keep up with the deluge.

“Today, most of the local sewers are required to carry much more water than they did when they were first put into service,” said Fore. “Consequently, they can exceed their capacity, resulting in backups and overflows due to insufficient flow capacity at some point in the sewer system.”

Gillian concurred. “Simply, it’s a matter of exceeding the capacity of the system,” he said. “When the ground gets saturated, the water runs off. It goes into the sewers or into the Deep Tunnel, which empties into quarries. When those are full, our backup is the Desplaines River. The water has to go somewhere.”

Unfortunately when there’s so much rain, that “somewhere” can include people’s basements.

What is the Deep Tunnel?

According to Fore, the MWRD has constructed 560 miles of intercepting sewers fed by approximately 10,000 local sewer system connections. Below this, is what is referred to as the Deep Tunnel but is officially known as the Tunnel and Reservoir Plan (TARP), a huge system of tunnels 8 to 33 feet in diameter that empty into three large reservoirs.

“TARP prevented more than 8 billion gallons from entering our streets, basements and polluting our waterways. However, TARP is not the answer for every flooding problem,” she said. “Sewer backups may arise for a variety of reasons, ranging from conveyance of water flow in local pipes, the groundwater table, undersized drainage designs and roof loads, and sump pumps attached to house lines.”

And when rain falls so quickly and so heavily, stormwater can enter sewers faster than it can flow through them, backing up into streets and unprotected basements.

As for the rumor that there’s a switch the village can flip to force the water to flow into the Deep Tunnel?

“If there was a flip like that, we’d use it,” said Gillian. “The village has no control over the flow of the water.”

What people may be referring to is the MWRD’s ability to reverse the flow of the Chicago Area Waterway system to Lake Michigan at two locations: the Wilmette Pumping Station and the Chicago River Controlling Works downtown.

“There are several factors we consider when determining to release floodwater to the lake, including the rate the river water level is rising at each lakefront control location, whether rainfall intensity is continuing or beginning to decrease, and the storm conditions on the radar,” said Fore.

As of May 18, Fore reported that the Wilmette Pumping station had started reversing on May 17 at 3:45 p.m. and at the Chicago River Controlling Works on May 17 at 7:20 p.m. and both were still ongoing.

How can residents protect their homes?

In Forest Park, there is an assistance grant program that reimburses residents for installing flood-control systems up to $1,500.

According to Gillian, “Over the last four years we have provided just over $75,000 in flood assistance grants,” which are available to owner-occupied properties, not income properties.

“Unfortunately,” said Gillian, “when we go a few years with no major rain events, people don’t apply.” He added that he’s currently looking into availability of grant money given the COVID-19 situation. Questions about the assistance program can be directed to village hall at 708-366-2323.

Gillian recommends that people do backflow preventive work on their homes and waterproof if there are any foundation issues. Although these systems aren’t always 100 percent effective and seepage can still occur, especially in old homes, they’re the best defense for homeowners against water entering houses.

In the short term, said Gillian, the village’s public works department will be picking up ruined and discarded furniture and household items from alleys and, if not possible to get into the alleys, from curbsides in front of homes.

Fore said the MRWD promotes Overflow Action Days, during which residents are encouraged to use less water at home.

“Launched in 2016 with our partners at Friends of the Chicago River, we urge residents to use less water at home when weather forecasts predict significant rain,” she said. “This allows sewers more capacity to handle increased volumes of water. We remind area residents to conserve water before and during rainstorms. Actions such as delaying showers or reducing their duration, flushing less, and waiting to run the dishwasher or laundry can help reduce the amount of water in the sewer system.”