Section 63(1) in Haryana Urban Development Authority (Erection of Buildings) Regulations, 1979
(1)Every drain shall -(a)be of a suitable size, and if it is intended for the conveyance of foul water shall have an internal diameter of not less than 100 mm.(b)be laid with a suitable fall and where practicable in a direct line. The standard gradient shall be 1 in 40 for a 100 mm drain and 1 in 80 for 150 mm drain. The maximum and minimum gradients shall respectively be 1 in 20 and 1 in 80 for a 100 mm drain and 1 in 40 and 1 in 140 respectively for a 150 mm drain.
