JOIN USRain water harvesting can help households to either obtain all of their water supply or supplement their existing supply. It diminishes dependence on water derived from the BWSSB/private tankers/borewells and checks devastating flooding too.
Water harvesting systems are designed for either storage and subsequent consumption of rainwater or its percolation through the soil-layers and recharge of the groundwater table.
Rooftop-RWH system channelises rain falling on the terrace towards one of these: a new storage tank, an existing sump or a recharge well/pit. Water from the storm-drains could also be led into recharge wells.
These wells could also be located in open areas like parks or larger plots’ free space. Lined with perforated concrete rings at the sides, with an unlined bottom, these wells augment water-levels in not merely one particular borewell, but the area’s general water-level. Households can also establish rooftop-RWH units catering to both storage and groundwater-recharge needs.
Rainwater stored for household consumption can be used for secondary purposes like washing, cleaning and gardening. But, regular cleaning of the terrace and the filter in the RWH-unit besides additional filtration at home renders the water potable.
The RWH-unit’s filter contains materials like graded metal, sand/gravel, plastic mesh and charcoal, helping eliminate organic matter, physical impurities and odours from the collected rainwater. Rooftop water-collection for direct use is recommended where the groundwater-level is high (say, at 3-4 ft.) and groundwater-recharging is superfluous.
Plumbers/contractors trained in RWH by the BWSSB, any other plumber or self-effort can be employed to install RWH-units.
The cost of incorporating RWH- units into fresh house-plans is lesser than retrofitting (establishing it for an already-built house-structure).
Retrofitting, however, doesn’t demand re-roofing or other major modifications.