Conner;4372262; said:Exactly the same situation I just had. Glad I don't have a bottom drain either, just a skimmer box. The pump can't drop the water level in the pond by more than about 10", so there will still be between 24" and 34" of water in the pond.
Glad you figured out the leak I used to have plants in my system but due to problem you are now having and the maintenance required to keep the plants under control they are all gone now.

In a properly designed gravity fed filtration system from a bottom drain you will burn the pump out long befoere you pump the pond dry.
 
But if you were using direct suction from the bottom drain there is the possibility.
Any bottom drain installation should be followed by a pressure test at around 10 Psi this way any leaks can be fixed long before fixing the leak becomes a major issue.