Section 23(2)(a) in The Chennai Metropolitan Water Supply and Sewerage Board's Water Tax and Sewerage Tax (Levy and Collection) Regulations, 1991
(a)If any building in the [Chennai] [Substituted for the word 'Madras' by the City of Madras (Alteration of Name) Act, 1996 (Tamil Nadu Act 28 of 1996).] Metropolitan area is demolished or destroyed, the owner shall, until notice thereof is given to the authorised authority be liable for the payment of the tax for which he would have been liable had the building not been demolished or destroyed.