Section 55 in Tamil Nadu Combined Development and Building Rules, 2019
55. Storm Water Drainage.
(1)Storm water drainage system in a site shall be designed in such a way to harvest cent percent of it to recharge ground water table below. The design factors of rain water harvesting structures within a site shall include type of soil and its absorption capacity, ground slope, intensity and duration of rain fall for the design period etc. However there shall also be a provision for carrying any excess storm water which was not absorbed during an exceptional rain fall, to drain or discharge into the street or public storm water drainage system.(2)No existing natural or man-made drainage system such as channel, canal, nallah etc. passing through the site shall be closed. When it is realigned within the site optimizing the usability of the site, due care shall be taken that its carrying capacity or velocity of flow is not reduced affecting the upstream and downstream sites and such a realignment shall be done only with prior approval of the Competent Authority and concerned agencies.
