MWRD: 1909 Willow Spring Spillway

(Satellite)

Randy Smith commented on a MWRD post
Can anyone tell me what this was for? This is located on the canal between Willow Springs and Lemont on the north side of the Channel. My guess would be it was to be used for flood control.
Metropolitan Water Reclamation District of Greater Chicago: That is a view of the decommissioned Willow Springs Spillway, completed in 1909, as seen from the Sanitary and Ship Canal. It's a bit complicated, but here's the story: The the spillway was used to divert flood water from the Des Plaines river into the Sanitary and Ship Canal. This was intended to reduce peak flood levels on the Des Plaines and also to provide more water for hydroelectric power generation at our Lockport Powerhouse. After a flood in 1954 threatened downtown Chicago, the Willow Springs Spillway was decommissioned - it was determined extra water from the spillway was contributing to problems upstream in the waterway system - there wasn't room for the extra water. In addition to the structure in your photo, the "approach channel" from the Des Plaines River is still there and can be seen from the Centennial Trail if you look for it.

Dennis DeBruler commented on MWRD's comment
Would you provide GPS coordinates for the channel? I found three 1939 aerials that cover the full length of the Centennial Trail, but I was not able to spot the channel.

Dennis DeBruler commented on MWRD's comment

Dennis DeBruler commented on MWRD's comment

MWRD commented on Dennis DeBruler's comment
Here's the location on Google Maps: https://goo.gl/maps/WMngmS3gu24DkAS18 . It's just about lined up with the end of the Columbia Woods parking lot on the other side of the Des Plaines. If you really want to nerd out you can see the topography of the channel and the levee that was installed to decommission the spillway (which the trail goes across) by searching for PIN 23-05-100-003 here: https://maps.cookcountyil.gov/cookviewer/mapViewer.html and viewing the topo map. The location is also circled on the aerial

Dennis DeBruler commented on MWRD's comment
Thanks for the Google pin and the black circle on the old aerial. The trees hide it really well. I checked out a 1928 Sag Bridge Quadrangle @ 1:24,000 since it doesn't have a copyright. The channel is in the lower-left corner of this excerpt.