This map depicts the location of the canals and remnant lakes (in dark gray). These water bodies are familiar to 21st century Chicagoans. Depicted (in blue) are the historic footprints of lakes, wetlands, and shorelines that have been altered and disappeared through draining, piping, and canalization.
Of particular interest is the modification to Chicago's primary inland waterway, the Chicago river. The top image gives an excellent idea of what the prairie river looked like prior to canalization. The lower image is of the Chicago River through the downtown Loop, looking westward from the Lakeshore.
Tunnels also lead to the Reservoirs.
When the Tunnels are at capacity, the combined water is tunneled to regional quarries currently being converting toReservoirs for holding larger quantities of untreated water.
Statistics and quantities of Chicago's urban water system are shown on the map. As of 2014, Chicago averaged a combined-sewer overflow weekly, and discharged untreated sewage to Lake Michigan twice annually. Street and basement flooding continue to occur on a regular basis.