the pond looses 1 inch a day but may slow in winter a little (but we get rain in winter usually). last year i let it go down a lot and spread bentonite around perimiter but probably did not use enough.
i fill the pond from my house well - but its hard to shower flush the chonicle down or make ice cubes for scotch. the well runs 24 hours every 4 days to keep it full currently.