minnew wrote:

Any opinions out there regarding a water powered sump pump as a back
up for an electrical sump pump? In theory, an independent back up
system sounds excellent, as opposed to a battery and/or generator.

A water powered backup sump pump is no more independent than a battery
or generator powered one. In all cases the pump is dependent on an
external power source. The main advantage of the water powered one is
the lack of maintenance required i.e. maintaining batteries or a
generator. Of course you have to have city water, if you have a well the
water powered pump isn't an option.

Since the backup pump is primarily applicable in a power failure
(assuming you maintain the regular pump properly so it doesn't fail), a
generator, particularly one of the little residential automatic units
can backup not only your sump pump, but also your refrigerator, freezer,
lights, heat, etc. so while it costs more than the water powered pump
it's worth considering. Those water powered pumps are kinda expensive
too. Those little automatic generators run on nat. gas or LP so if you
don't have those they aren't an option.