Remember When: Circa 1900 dams on Allegheny River eased some problems, caused others
The concrete locks and dams along the Allegheny River were built in the 1920s and 1930s, but three dams built around 1900 preceded them. Lock and dam No. 1 was located at Herrs Island near the present 31st Street Bridge. Lock and dam No. 2 was built slightly upstream from
Source: triblive.com