Section 6(2)(vi) in The Chennai Metropolitan Water Supply and Sewerage Act, 1978
(vi)to prevent pollution of any water including any water source, water course or channel utilised for the purpose of 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;