​Reversing the River’s Flow

​While the Chicago River continued to play a minor role in commerce, the growth of Calumet Harbor made it necessary to adapt the area’s inland waterways to the needs of the rapidly expanding Chicago area.  In 1900, the Metropolitan Sanitary District succeeded in permanently reversing the flow of the Chicago River.  Since the late 1860s, city engineers had used pumps to draw water from the river into the old Illinois and Michigan Canal, thereby reversing the flow.  The Chicago and Sanitary Canal improved on that by creating a wider and deeper waterway to pull clean water from Lake Michigan.