People building dwellings in flood plains was a known problem when I arrived in California almost 50 years ago. So was building on hillsides with a particular slope, because surface soil dries out over 7-8 months "dry season" and one good rainfall (say from the "Pineapple Express" atmospheric river) would saturate it and there were slumps/landslides all over. 

I lived in two houses (one I owned) where the Hayward fault went right past the door. I spent six months of Sundays with my pals round the corner "earthquake proofing" their house (consisting of bolting the wooden frame to the foundation).

I don't know that things have changed. Insurance companies mostly won't insure for flood or landslide risks. The advice was and is: get a good geophysical evaluation; if you can't get a decent insurance quote, don't buy/build.

You can only proof a dwelling against a guessed magnitude of threat. You can guess such a magnitude from history (if there is enough) and from geophysical assessment. But, you know, extremes are starting to happen (for example, the mid-July floods in Germany, Luxembourg and Belgium were, I think, without known historical precendent). 

But suppose you already have the building. The only general practical measure I can think of in designed the electrics to be flood-resilient is to establish level circuits at various levels, with separate breakers. Then what about the control panel? You'd need it upstairs, rather than down. But if it is up, and you have a building fire, what do you do then? Maybe you need two panels in series; one in basement/ground floor in a guaranteed-waterproof installation, feeding another one upstairs, from which the individual building circuits are derived? 

(Good exam question, BTW. Pity I no longer teach.)

People building dwellings in flood plains was a known problem when I arrived in California almost 50 years ago. So was building on hillsides with a particular slope, because surface soil dries out over 7-8 months "dry season" and one good rainfall (say from the "Pineapple Express" atmospheric river) would saturate it and there were slumps/landslides all over. 

I lived in two houses (one I owned) where the Hayward fault went right past the door. I spent six months of Sundays with my pals round the corner "earthquake proofing" their house (consisting of bolting the wooden frame to the foundation).

I don't know that things have changed. Insurance companies mostly won't insure for flood or landslide risks. The advice was and is: get a good geophysical evaluation; if you can't get a decent insurance quote, don't buy/build.

You can only proof a dwelling against a guessed magnitude of threat. You can guess such a magnitude from history (if there is enough) and from geophysical assessment. But, you know, extremes are starting to happen (for example, the mid-July floods in Germany, Luxembourg and Belgium were, I think, without known historical precendent). 

But suppose you already have the building. The only general practical measure I can think of in designed the electrics to be flood-resilient is to establish level circuits at various levels, with separate breakers. Then what about the control panel? You'd need it upstairs, rather than down. But if it is up, and you have a building fire, what do you do then? Maybe you need two panels in series; one in basement/ground floor in a guaranteed-waterproof installation, feeding another one upstairs, from which the individual building circuits are derived? 

(Good exam question, BTW. Pity I no longer teach.)