Some photos from a tour of the historic facility that is still in use as one of the waterworks’ intakes. It’s really quite incredible how well preserved it is and the ongoing conservation efforts. The chamber is the same width as the main floor all the way to the bottom which is well below the bottom of the Ohio River, and was entirely dug by hand. The tour guides were excellent and very knowledgeable, and have a website with a lot of information:

https://cincinnatitriplesteam.org/index.htm