Section 173A(2) in The Mumbai Municipal Corporation Act, 1888
(2)If under the terms of the tenancy, the rent charges for any such tenement is inclusive of water tax and subsequently water is supplied thereto through a common meter and if water charges are paid by the owner or any person acting on his behalf, such owner shall be entitled to recover under this section from the occupier of such tenement only the difference between the water tax previously payable by him and the water charges payable in respect of such tenement on pro rata basis under sub-section (1).