It is common to replace the impeller.
Next time, consider researching (e.g. Consumer Reports) and getting a
USA-made pump. We have dealt with water-gardening pumps for years and
since the manufacturing plants moved overseas (including Little Giant),
the quality declined. Foreign companies are even putting the UL, AIG,
and other approval stamps on their products without getting the lab's
approvals.
More and more pumps and motors are returned before the warranty is up.
It seems that foreign countries don't have the metallurgy technology
down to properly build the motors.
Pumps aren't the only item. Anything with a motor seems to not last as
long as it used to when manufacturerd in the USA.
This doesn't apply to foreign companies that are owned or closely run
by American companies.
The old adage applies, you get what you pay for.

David wrote:
I have been using a Pondmaster Pump in my pond. It is a 1500 gph pump and
has been a pretty good pump, although I have had to replace the impeller
twice. It recently died and I was wondering what other options are out
there. I need a pump that is low maintenance and can handle a bit of abuse
if I don't clean my pre-filter as often as I should. Any advice?