With water crisis always reminding us of the need to conserve resources, traditional rainwater harvesting system is becoming dearer by the day. Jigisha Doshi explores different models of the system A rainwater harvesting system was installed four years ago by the Chavada family in Bimanagar area of the city. Bimanagar has a common system which inspired them to set up their own. Municipality water was the only source for them earlier, and their fear was whether the water was good enough for drinking and cooking. They have a rooftop harvesting system now which helps them achieve domestic water security. As they already have an underground water tank, they could save a considerable sum. A pipeline from the roof is connected to the filter tank through which water goes to the underground tank. A mini hand pump is also attached to the tank. With an average rainfall of 640 mm/year, the system meets 50 per cent of their needs. It cost them Rs 1,300 and the maintenance charges are just Rs 100 per annum. The Chavadas no longer depend on the borewell in the society or the irregular municipal supply. Manali Apartments, Atira road ESociety set-up arlier, a borewell was meeting its water needs, but in 2002, a system was set up to recharge the borewell through a rooftop rainwater harvesting system as well as groundwater recharging system. Apart from recharging the borewell, the society has also introduced a proper collection system for storm water to avoid waterlogging. The water is collected in a tank which connects to the borewell directly. Through another system the surface water goes to filter tank and then to a well to raise the ground water level. Both the systems also help avoid water logging in the apartments.The bore recharge system costs about Rs 35,000 and the well recharge system is about Rs 18,000,with maintenance costing Rs 500. It meets 70 per cent of the demand and benefits the society to secure its future. Gujarat Cancer Society, Vasna Institutional set-up The only source of water, for the 6,000 sq m campus at Vasna, is a borewell. It does not get municipal water. With soaring demand, the need for recharging ground water was realized, and, in 2002, with the help of Pravah and Viksat, a huge rainwater harvesting system was developed. Rainwater is collected from the ground surface as well as rooftops of buildings through channels and pipelines and enters a recharge well after passing through a filter. Because of the system, 2.3 lakh litres of ground water gets recharged and electricity use is also cut. Establishing the huge plant cost Rs 2.8 lakh and it meets 24 per cent of the demand. Maintenance cost is Rs 14,000, but it is recovered through electricity charges and the saving on water tanker charges. Naroda Industrial Association office Industrial set-up There are almost 1,200 industries and 800 residential units here, which were totally dependent on the GIDC borewell system. To recharge this borewell, rainwater is collected in a well through surface drains or natural slops after filtering it through layers of pebbles. This system helps maintain ground water level and increases the life of borewells in the vicinity too. Thus, the ecological benefits are huge and the association has the satisfaction of giving something back to nature. The system cost around Rs 40,000, and maintenance charges are Rs 1,000. And, what is heartening, is that the system meets 100 per cent of the demand.(SOURCE - PRAVAH)