Someone wrote?

Yes, but a water powered pump is still reliant on an external power
source.

Not clear on that! But not familiar with water powered pumps! What are
they; some sort of venturi jet?
Our municipal water supply, is gravity fed.
The only thing that 'might' fail is the chlorine injection at the main
control station near the lake that supplies the town.
In other words we never lose water pressure? And the main lines are
sized for fire fighting hydrants.
So would it not be true, in our case anyway; a water powered pump
would not be reliant on external power?
Curious.