Section 128(3) in West Bengal Municipal (Building) Rules, 2007
(3)The drainage from the roof and compounds paved or un-paved, will be permitted to flow over footpath into the kerb drains and ultimately into gully pits. Drainage from roof or compound, paved or un-paved, must not discharge into or be connected with any soil pipe or soil ventilation pipe or any waste ventilating pipe nor shall it discharge into sewer.
