The Thornton Composite Reservoir has dropped to 73% full after nearly reaching capacity last week. Thornton Village Administrator Vivian Payne said Tuesday reports of bad odors coming from the reservoir were sensationalized by the media.

Board meetings are open to the public and can be streamed online.

Chicago is building a $12 million pilot project that will capture and temporarily store nearly 1.7 million gallons of excess stormwater in an underground detention system during heavy rainfall and gradually release it into the sewer system as capacity becomes available. The Wing Storage project — a partnership between the Chicago Department of Water Management and the Metropolitan Water Reclamation District of Greater Chicago — will be installed beneath city streets and attached to existing sewer infrastructure on Chicago’s West Side, where major storms caused severe flooding in 2023.

The Metropolitan Water Reclamation District of Greater Chicago (MWRD) expects to have two projects totaling $5 million to address odor mitigation near its Thornton Reservoir completed by the end of 2026, bringing total mitigation efforts over the past decade to $8.6 million, according to officials.

The massive Thornton reservoir, a south suburban quarry holding billions of gallons of stormwater and sewage that nearly filled up this past week, will take at least a month before it drains. Thornton is part of the Deep Tunnel flood-control system and resembles a canyon in South Holland. It takes in sewer wastewater during heavy storms that is later pumped out to the Calumet treatment plant at East 130th Street in the Far Southeast Side Riverdale neighborhood. For the first time since opening in 2015, the quarry filled to near capacity along with another flood-control reservoir known as McCook in Bedford Park.

The nearly 8 billion-gallon Thornton reservoir, which helps prevent flooding, was nearly full this week. The sewer water is slowly being pumped out but it will be weeks before the south suburban quarry is dry again.