This shows the 4 foot high subsidence directly over the main west side sewer collector at Irishtown Bend.   The entire hillside up towards W25th Street is visibly unstable along this stretch of roadway.   And the area has historically been unstable, that's why there are no buildings on it.    The NorthEastOhioRegionalSewerDistrict ( NEORSD) has installed a dozen or so slope inclinometers (a drilled well with a slope indicator in it) to monitor the subsidence.    

In my opinion, (I have a little geology training) this entire area could slip into the Cuyahoga River at any time.  And if that happened,  much of the sewerage from the southerly portion of the West side of Cleveland would dump untreated into the River and into Lake Erie where, three miles offshore, the Cleveland water intake crib sits. 

We would be fine, however, because the Water treatment plants could just add more chlorine!