Section 55(1) in Tamil Nadu Combined Development and Building Rules, 2019
(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.
