Finding a location from which to photograph this waterfall proved quite the challenge. The east bank is inaccessible. It's blocked by a sheer stone wall that is topped by dense trees and bushes. The west bank has no access to the waterline, but I did find one location that had a wall short enough for me to photograph over. I'd have preferred a waterline shot, but it's simply not possible.
These falls are directly under the Main Street bridge in Pawtucket. I haven't found a time of day where the entire falls receives a similar amount of light so I settled for a morning shot where the foreground was in deep shadow. This photo was taken using a 10-stop ND filter, shooting at ISO 100 and f/11 for 20 seconds.
Post processing started with a classic filter in Topaz B&W FX. I then adjusted the color sensitivity sliders to provide better detail in the water. The adaptive exposure, regions, brightness, contrast, boost black, and boost white sliders were then adjusted. In PSE I added a slight levels adjustment and a sepia photo filter.