Expert Lectures Delivered

RECENT EXPERT LECTURE DELIEVERD ON

"RAIN WATER HARVESTING"

Dr. S. M. Yadav, Professor, Civil Engineering Department have nicely explain how the rooftop rainwater can be harvested. Recalling the “Day Zero “ (19th June 2019) for Chennai city when all the three reservoirs of the city get dried and there was ‘’No water” to supply. He feared what will happen to Surat city, if Ukai reservoir dried out completely which is major source of water supply for the city of Surat. In past Surat has faced restricted supply hours due to shortage of water in the Ukai reservoir. In the city development plan 2035 it has been clearly mention about the compulsory Rain water recharging as one of the solution to fill the gap between demand and supply.

Prof. Yadav has explained how economically roof top rain water can be harvested. He said from the roof top area of 1000 sq feet in the city of Surat one can harvest 75,000 liters of water which is sufficient for family of four people for 120 days. In the SVNIT campus though the monsoon season is over just now, the water is available at a depth of 25 feet and may go further down with the time. He explained how the rain water can easily be diverted to bore hall. After flushing out first rain water the water can be diverted to recharge well either using on line filters readily available in the market or using purpose built filter made with coarse sand of 1.5 to 2 mm size at the top followed by gravel of 5 to 10 mm size and boulders of 5 to 20 cm at bottom. The thickness of each layer should be about 0.30 m. The water can be stored in the underground or above ground closed tank. A pump which cost little may be mounted on the top of this tank to pump water without opening the man hole of the underground tank. The Dang district receive 2100 mm of rainfall but the people of Dang district strive without water during summer season. The people of water store and use conserve rain water during summer season. He explained how to recharge abandoned well. Before recharging the abandoned well the water level in the well be measured and after that approximately 5000 liters water is suppled in this well. If this water is absorbed by the well than it is fit for the recharging. A pit about 3m * 3m having depth of 2.7 m is excavated around this pit. The slits are made alternately on this pipe for water recharging. This pit is filled with big size boulders having size of 20-30 cm about the one third depth of the pit. This is followed by spreading of 15-20 cm stones above it. The top layer is filled with soil and a permeable fine mesh is laid over it. This fine mesh is covered over by fine sand. Thus, the well is ready for the recharge.