When the Chicago River was reversed in 1900, the city’s sewage was directed away from Lake Michigan, the city and surrounding suburbs’ main drinking water source. However severe flooding leads to sewage tainted storm water being put in the lake. Raw sewage can be harmful to the lake and local rivers and has led to the severe pollution of the Chicago River.
State Representative Margo McDermed recently toured the McCook Reservoir, a new addition to Cook County’s reservoir system that will have a significant impact on flood control. The reservoir is 3,000 feet long, 310 feet deep, and has the capacity to hold 3.5 billion gallons of storm water. By 2029 it will be able to hold an addition 6.5 billion gallons.
The tour also included a look at Chicago’s ‘Deep Tunnel’, the largest public works project ever undertaken by the city of Chicago and one of the largest civil engineering feats in modern history. The tunnel connects sewers to reservoirs that hold storm water until it can be pumped to sewage treatment plants for cleanup before being put into local water sources.
The new reservoir and tunnel are part of a much larger project that began in the late 1970’s and is expected to be completed in 2029. Once the project is completed, water management agencies will no longer have to pump excess wastewater in to Lake Michigan and the river during severe weather events to prevent flooding.
The McCook and Thornton reservoirs, connected via the Deep Tunnel, were built out of large rock quarries recommissioned for public use. Rep. McDermed has pushed for greater regulation of private rock quarries and their impact on local drinking water. These debris and quarry sites are often high in toxins, which can seep in to the groundwater. You can read more here.