82%[0] of Australian utilities' water comes from surface sources, so you'd need to look at only the section of the population who drink exclusively groundwater.

82%[0] of Australian utilities' water comes from surface sources, so you'd need to look at only the section of the population who drink exclusively groundwater. [0] https://www.bom.gov.au/water/npr/docs/2022-23/Urban_National_Performance_Report_2022-23.pdf https://www.bom.gov.au/water/npr/docs/2022-23/Urban_National...