https://en.wikipedia.org/wiki/ARkStorm
https://en.wikipedia.org/wiki/Great_Flood_of_1862
A Harvey-like flooding can happen without a hurricane, apparently.Native Americans knew that the Sacramento Valley could become an inland sea when the rains came. Their storytellers described water filling the valley from the Coast Range to the Sierra.
Not wanting to start the whole climate change debate (please don't), but it seems like these kind of events will occur more frequently from now on.
https://www.washingtonpost.com/news/won ... dfcf12b348
If you own a house anywhere in a 1000 year floodplain it seems to make sense to purchase flood insurance, or get out.
Also, just physical safety plans. An event like the 1862 flood would cause serious problems across much of the West. I know I'm not currently prepared for something like that.