Section 4A(3) in The Special Rules for the Mulit-storeyed and Public Buildings, 1974
(3)Wherever existing water storage sumps are available, the rain water so collected, after it passes through the filter, shall be allowed to flow to the sump through closed pipes. An overflow pipe shall be provided to the storage sump so that the surplus water is led into the nearby openwell or borewell or percolation pit.
