Another issue I saw on the news was that firefighters couldn't fight a fire because the water pressure was too low. Turns out the water utility lost power and didn't have any backup power. They couldn't pump water from the wells.

Most regions have some sort of above-grade water tanks. Not the water towers you'll find in the plains states, but tanks built upslope of served areas. Though these are filled by powered pumps, they'll supply enormous amounts of water even after power is cut.

In San Francisco there are numerous reservoirs, virtually all decked over. Four of the highest are located near Twin Peaks, the highest point in the city:

https://www.google.com/maps/place/Sutro+Reservoir,+San+Franc...

I guess the problem is for places that don't have that.

You'd be hard-pressed to find such in California, is my general point. I'd be interested in specific citations of exceptions to the rule.

Appreciated