How so? NOT COUNTING leaks and filling, the average Olympic sized swimming pool uses 1-2 million gallons of water a year.
See EPA Commercial Pooland Spa Equipment Best Management Practices for Commercial and Institutional Facilities https://www.epa.gov/system/files/documents/2023-11/ws-commer...
It's basically like framing power consumption in watt hours. A million watt hours is tiny at any scale, your whole neighborhood uses millions every day.