Section 18(b) in The Metro Railways (Construction Of Works) Act, 1978
(b)alter the course of any rivers, canals, brooks, streams or water-courses for the purpose of constructing tunnels, passages or other works over or under them and divert or alter as well temporarily as permanently, the course of any rivers, canals, brooks, streams or water-courses or any drains water-pipes, gas-pipes, electric lines or telegraph lines or raise or sink the level thereof in order the more conveniently to carry them over or under, as the metro railway administration thinks proper;
