Another thought or two:

Since (presumably) the system will be inoperative for months at a time,
you might consider a diesel system instead of gasoline-based. The diesel
fuel will keep better than gas, is readily available and is safer to
store.

Someone mentioned that their propane tanks floated away. Of course your
gasoline or diesel containers would do the same thing. Store them higher
than the generator. If they float away, you won't be able to use the
generator anyway because it will be under water.

Noise from the generator:

You're only using it for extended periods of time during emergencies,
right? Your neighbors should understand that there's an emergency under
way. Maintenance operations will be of short duration and to keep peace
with the neighbors, offer to consult with them on their own emergency
plan.

If everyone in your neighborhood gets a generator, maybe you could set
up regular maintenance dates/times so that everyone generates noise at
the same time, rather than multiplying annoyances. Your neighbor's
generator will be making so much noise that he won't hear yours.