by Vanessa Villarreal, USACE Chicago District, Public Affairs Office
On May 17, 2020, the U.S. Army Corps of Engineers, Chicago District activated its Emergency Operations Center (EOC) in response to record rainfall and flooding of the Chicago River and surrounding areas.
EOC flood teams, made up of civil and hydraulic engineers, were dispatched to the Chicago River and several project areas in the district’s area of responsibility, including Chicago Union Station, Lower Wacker Drive, Chicago Riverwalk, Little Calumet River levees, Cady Marsh Tunnel, Forest View levee, Groveland levee, McCook levee, Joliet levee, Ottawa levee, and the Chicago Sanitary and Fish Canal electric dispersal barriers.
“The district trains regularly for this type of situation and is fully prepared to provide any required emergency response support to our state and local partners,” Michelle Kozak, chief, Emergency Management, said. “We’ve also partnered with emergency operations officials in affected areas to provide the assistance the Corps is authorized to provide.”
“The Chicago Lock was opened about 7:30 p.m. on Sunday, May 17 to allow the rapidly-rising Chicago River to backflow into Lake Michigan,” Bill Rochford, chief, Geotechnical Dam & Levee Safety Section, said. “The gates remained open until 5:30 a.m. on Monday, May 18. The conditions at T.J. O’Brien Lock and Dam were being monitored and were close, but did not require opening.”
The opening and subsequent closing of the gates at the Chicago and T.J. O’Brien locks are coordinated with the Metropolitan Water Reclamation District of Greater Chicago (MWRD), who has overall management responsibilities for the water levels of the Chicago-area waterways.
“When we have large amounts of rainfall and the river starts to rise, we work with MWRD to try to maintain the river level,” Tyrone Valley, lockmaster at the Chicago Harbor Lock, said. “Unfortunately, Lake Michigan is at record levels, so backflow cannot occur until the Chicago River is higher than the lake in order to allow backflow to occur. As a result, significant flooding occurred in the downtown area that impacted operations at Chicago Union Station and shutdown Lower Wacker Drive, and flooded the Chicago Riverwalk and caused other issues in the downtown area.”
“Record water levels were also encountered along the Chicago Sanitary and Fish Canal electric dispersal barriers near Romeoville, Illinois,” Rochford said. “The length of the fence was checked to ensure that fish would not be able to move across from the Des Plaines River into the CSSC above the electric barrier.”
The Chicago District is also providing technical experts to assist with levee monitoring. A team also was dispatched to check on a couple of new levees in the Chicago District’s area of responsibility.
The Forest View levee had a final inspection last Friday, May 15, and needed to withstand a near record flood on Monday, May 18.
“The levee performed very well,” Rochford said.
A flood team also inspected the newly-acquired Ottawa levee and met with its sponsor and a representative from the USACE Rock Island District to inspect it and ensure everything was working well. The levee is located at the confluence of the Fox and Illinois rivers, and the Illinois River was just below record levels. This has been the third time in three years that the Ottawa Levee had near record levels.
The district urges residents in impacted areas to listen carefully to instructions from their local officials and take the recommended protective measures to safeguard life and property.
“If members of the public need sandbags or have questions about potential flooding in their community, they should contact their city or county emergency management offices,” Kozak said.
Residents are encouraged to be vigilant, aware, and ready to take necessary precautions as warranted. Do not drive into high water and do not drive around barricades for your safety and the safety of first responders.
“Our district’s projects are performing as designed following this week's flood event,” Kozak said. “Engineers and hydrologists continue to monitor the situation 24/7.”