From what I can tell, you could improve the inflow by contouring the land around the pond to capture more runoff. Similarly you could add some drain tile to your land and connect up the gutters also. The pond just has to be sized appropriately with the amount of area you can capture.
For example we need about 7 to 8 acres to support a single acre non leaky pond. We have somewhere in the vicinity of 12 acres in a leaky half acre pond and it works well enough.