- 51.1 Provision of rainwater harvesting shall be mandatory for 300 sqm. and above size of plots-The dimension of recharging pits/trenches shall be at least 6 cubic meters for every 100 Sqm. of roof area. Percolation Pits shall be filled with small pebbles or brick jali or river sand and covered with perforated concrete slabs. Apart from this, the following requirements are optional and may be provided depending on site conditions.51.1.1Terrace Water Collection: The terrace shall be connected to a sump or the well through a filtering tank by PVC pipe. A valve system shall be incorporated to enable the first part of the rainwater collected to be discharged out or to the soil if it is dirty. A filtering tank measuring 0.36 Sq. m. can be constructed near the sump. The tank can be divided by a perforated slab and one part should be filled by small pebbles and other by brick jali. The bottom portion of the tank should have aslope' to avoid stagnation of water.51.1.2Open Ground: Where there is open ground, a portion of topsoil shall be removed and replaced with river sand to allow slow percolation of rain water. Any other method proved to be effective in conservation and harvesting of rainwater may be adopted in each and every construction taken up.
