My Pennsylvania family lived in Lock Haven and Mill Hall, and nearby towns. I know that in Mill Hall, my great aunts always spoke of their parents being "in" the Johnstown flood, even though they weren't in Johnstown. Mill Hall got flooded every time there was rising of the Susquehanna River and its tributaries. And several of my great aunts kept on returning to their flooded homes, cleaned them up, and went on living in their lowland habitat.
My grandmother spoke of one flood in which the water engulfed the first floors. She offered shelter to a few community members in her 2nd floor apartment. I would have to check on the dates, but I'm assuming early 20th century, as she was born in 1897 and didn't leave home until after 1915.
Even in the flood of 1972, my great aunts refused to leave their homes by the river! My own second child was born during that flood - and the hospital in Tyrone, PA where I went to deliver, lost their water supply. The bridge between our home in State College and Tyrone was washed out, but my husband found an alternate route to bring me water to drink!