Hong Kong Regulations

BUILDING (STANDARDS OF SANITARY FITMENTS, PLUMBING, DRAINAGE WORKS AND LATRINES) REGULATIONS - REGULATION 61

Surface water channels

(1) Channels provided for the carriage of surface water shall be of adequate
size, constructed of approved impervious material, finished off smooth and
laid to a gradient of not less than 1 in 100.

(2) Suitable grilles shall be provided to prevent sand, silt and other debris
from entering any public sewer, public channel, nullah or stream course.

(3) A cover in a foot-path to a channel for the carriage of surface  water
shall be flush with the path surface and any hole in such cover or between
such cover and another shall not exceed 20 mm in one dimension. (L.N. 366 of
1984)