“… two “1,000-year” floods in Ellicott City two years apart…”
That’s what happens when you build your Main Street over a river which runs through low hills, and the rest of the town in the gully the river made, paving over everything.
How true. A local town near here(Siloam Springs AR) built along a stream. In 1974 a flood washed away the downtown.
Now I think of it, several towns on old maps are no longer there. They were built right next to streams that flooded.