@MN Transplant or anyone else that knows…
Showing my ignorance again, but I’m walking the C & O canal out near Williamsport and passed a flood stage marker. It never occurred to me that I don’t know this, but what is zero? Is flood stage measured by the depth of the river? For example, in 1936 the water reached a flood stage of 48 feet. That was the depth of the river? Or is that 48 feet above the normal height?