Individual water meters

How to bill flats on basis of individual water meters?

Multiple liters used to a number and get a Rupee amount? Use slabs?

No, need to apportion bills from external vendors (Government, water tankers) and share costs using reading from Water meters of each apartment and common areas ...

The amount we use is from four sources, STP (for garden and toilet), borewell small part, rest is BWSSB & water tankers. Add all bills from BWSSB, water tanker, expenses, like repair, maintenance, electricity for pumps to 11th floor ...

Note usage in common areas (separate meters), deduct that. The remaining cost apportion in slabs as agreed upon earlier, as a flat using more than average means more cost for all thru more expensive tankers and can lead to scarcity, when supply is less. Take individual water meter reading to get ratios of different flats. Use a spreadsheet...water meters gives output in CSV plug it in and add to each flat using building maintenance software, examples: apna complex, no broker hood