Section 133(3) in The Bombay Provincial Municipal Corporations Act, 1949
(3)The sum to be paid annually to the Corporation by the [State] Government shall be eight-tenths of the amount which would be payable by an ordinary owner of buildings or lands in the City, on account of the general tax, on a rateable value of the same amount as that fixed under sub-section (2).Special Provisions Relating to Water and Conservancy Taxes