Rainwater harvesting has been practiced for ages through paddy cultivation, which allowed the water to collect and percolate through wells that collected water and recharged the water table. On the way to modernisation, we have forgotten all of this
Goa receives thethird highest rainfall in the country with 2500mm in the coastal belt and4000mm in the vegetated regions. Yet many parts of Goa suffer from waterscarcity, with people buying water from tankers. “Only one-third of therainfall we receive annually would meet the yearly water requirements of thepopulation of Goa,” says Darryl Pereira, CEO of Reira Eco Ventures which isinvolved in rain water harvesting among other eco activities.
Where could wehave gone wrong? The answer lies in our ignorance of how to wisely harvest rainwaterfor usage and for recharging the groundwater table. In earlier days,groundwater was recharged by the standing water in paddy fields and throughwells that were part of every household. Modernisation has sent these methodsinto oblivion.
“Rainwater canbe allowed to percolate into the soil by having traps – holes filled withgravel – every 3-5 meters in drains that carry rainwater. Our folly is inlining the drains with concrete,” says Pereira. In the hilly regions such asPernem and Malkarnem, organisations such as The Mineral Foundation of Goa have implementedwatershed projects – funded by the Central Government – which ensure groundwaterrecharge by slowing the flow of water along the slopes and allowing itspercolation. The conserved groundwater can be tapped into during the dry months.
For usage, rooftoprainwater can be stored in a tank fitted with a simple filter. “This system iseconomical in regions where the rainfall is spread throughout the year and inGoa it is feasible for organisations such as hotels and schools which have alarge number of residents who will use the stored water on a daily basis. Homescan have a separate plumbing system that channelises rainwater from the roof,or water can be stored in a temporary storage or a farm pond,” says Dr SachinTendulkar, Senior Programme Manager at the Mineral Ore Foundation.
The NationalHorticulture Mission gives subsidies for rainwater harvesting using farm ponds.“The PWD gives subsidies for channelling rooftop rainwater in homes after thehousing plan is approved by the TCP,” says Dr Tendulkar. Rainwater harvestingsystems can be seen at the Goa University in Taleigao and DLink in Verna.
