Nandi Deepa, an apartment complex built in 2005 on Bannerghatta Road, has 109 occupied flats with 350 to 450 residents. The complex does not receive BWSSB’s Cauvery water, has 4 borewells, of which only one was used, and an STP (Sewage Treatment Plant), the treated water from which is used for flushing toilets and gardening. The complex requires between 48,000 to 50,000 litres of fresh water per day, which was mainly supplied by water tankers, costing the residents Rs.14 to 16 lakh annually.
In June 2020, the new Residents’ Welfare Association (RWA), decided to implement sustainable water initiatives and lower the expenditure on water. The RWA revived the existing open well and borewells and implemented rainwater harvesting and groundwater recharging.
Digging of recharge wells
*Biome does not recommend direct borewell recharge with surface runoff or stormwater, as it can contaminate the deep aquifers. Only clean, filtered rooftop runoff should be used for direct borewell recharge.
Open well during and after cleaning
After the borewells were revived:
|Total capital cost in digging recharge wells and cleaning open well||Rs 22.2 lakh|
|Decrease in monthly water costs (from 14 to 7 water tankers)||Rs. 62,720|
|Further decrease in monthly costs (from 7 to 4 water tankers)||Rs. 35,840|
|Potential annual decrease in water costs||Rs. 7,52,640 + Rs. 4,30,080 = Rs 11.82 lakh|
So the community could recover their capital costs in just two years!