Yeah, after Katrina there was a lot of talk about how something similar could happen here if there was a major flood that broke through the levees. As a result there are improvements to Folsom Dam underway as well as the upcoming improvements to the levees mentioned in the previous post that should help mitigate that risk.
Ah, Sacramento - where the architect for the capital building ended up in an asylum. Possibly due to stress. Possibly because he was never given more than a year’s funding at a time, for a project that lasted 14 years. It sure didn’t help that there was a flood as soon as the ground had been prepared and it became obvious that ground level would need to be raised.
Before settling on Sacramento, California had played musical capitals for awhile. But in the mid-1800s, all the big cities were located on rivers because boats were the surest form of bulk transportation. So any capital location chosen in that era would have a possible flooding problem. And Sacramento was as close as you could get to the gold fields near Sutter’s Fort without getting off the boat and buying a horse.
In fact check out the California Delta. Sacramento is a bit north of the area shown on that map.
From what I’ve heard John Sutter knew the area had a high risk of flooding and advocated for the city to be located elsewhere on higher ground, but the rest of the businesses community wanted it where it is because that was the prime location for selling supplies to miners heading to the gold fields.
I wouldn’t have the slightest idea what natural disaster would impact San Antonio… a hurricane, possibly… but that hasn’t happened in the past 10 years, assuring me it won’t happen in the next 50 or so. 
Columbus did it by caravel.
Coastal New Jersey on a barrier island. The biggest threat is hurricanes or nor’easters. Our house got more than a foot of water in it from Sandy but since then we’ve elevated. It would take a record breaking storm to have much impact on us now. Living at he beach is pretty darn nice. That said, if I had to do it all over again, I’d chose to live in the mountains.
The plane of it’s day, I suppose!