Thanks for all the replies.

Wow there’s quite a lot to consider! I'm starting to see how one gallon per day per human is a minimum.

My dogs are both quite large, 33 & 37kg (approx 70 & 80lbs), so would expect their consumption to be significant.

As for likely scenarios, I think I am quite lucky. Singapore isn’t really near any fault lines so that pretty much rules out seismic activity. We are also sheltered by the huge land masses of Indonesia so hurricanes/typhoons would normally dissipate before they could ever get here. Singapore was completely spared in the 2004 Boxing Day tsunami and earthquake even though many place nearby were hit very badly.

My house is also on fairly high ground, so I don’t think flooding should be a problem if we bug-in at least. But then again nothing is ever 100%.

I am more worried about things like disruption in utilities.

Yes the koi pond would be a very large reservoir of water if need be.

I certainly hope I’d never be in such a dire situation to even consider eating the koi!

I like the idea of have rain barrels at each corner of the house but they would be the perfect breeding ground for mosquitoes.