I've installed a 3/4" hose bib after my pump so when I do water changes my pump feeds a buried soaker hose that runs through all the flower beds in the yard. A little valve tree to keep the pressure to each hose somewhat balanced and a timer on my fresh water hose. I turn on the fresh water, open the valve to the soaker hose, and 1 hour later my water change is complete and the flowers are watered. It took some juggling for me to get the flows balanced but now it's dialed in and a snap to do. The timer on the fresh water, and the low water shut off keeps my pump and my koi safe! ( I have to allow for the "putz factor" in everything... I'm a little ADD most of the time

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This by no means addresses the volume of water "wasted" however, because unfortunately I'm certain I wouldn't be watering that frequently or heavily if it weren't for the pond needing a change of water...
My best guess? Probably not a happy one for a lot of people, but the only solution I can think of is absolute MINIMUM stocking levels and the very infrequent water changes that this would allow. I imagine 1 fish per 10,000 gal and the need to change your water wouldn't be that severe.
Personally, I recognize the water I consume with my pond, and in all honesty, do my best to use very little for anything else. I don't water the lawn unless it's pond water. I'm not out running a pressure washer every other week. I did install low flow shower heads (and I hate those things) and we changed our dishwasher and washing machine to high efficiency models. I guess it's a bit of give and take within reason. And for me, my water isn't metered as I'm in a gated community and pay a flat rate.
Grant