"The massive system of tunnels and reservoirs was built to contain Chicago’s floodwater, protect area rivers and Lake Michigan. Now, there’s a risk that suburbs will flood and sewers will overflow into Chicago waterways."
"For the first time in history, Deep Tunnel, Chicago’s massive system of underground tunnels and reservoirs designed to hold floodwater, is almost completely full after a weekend of heavy rain.
Built over more than a half-century, Deep Tunnel sends floodwaters from Chicago and nearby suburbs through more than 100 miles of tunnels into three reservoirs located just outside of the city. It was designed to help protect area rivers as well as Lake Michigan.
The Thornton reservoir in south suburban South Holland was at 94% capacity Monday. The McCook reservoir in southwest suburban Bedford Park fluctuated between 96% and 100% full. Between the two, they are holding around 11 billion gallons of water."
