Average annual rainfall in Gurgaon - 577.8 millimetre (mm)
Total volume of water harvested - 23549.32 cubic metre (m³) or 2,35,49,320 litres
This represents 45.8 per cent of the total rainwater harvesting potential.
WATER SUPPLY SOURCE
The four borewells inside the colony provide around 5.5 lakh litres of water every day.
RAINWATER HARVESTING SYSTEM
Rooftop rainwater harvesting:
Rooftop rainwater from the MA 1/2 block is diverted into a recharge well through a series of chambers and interconnected pipes. This recharge well measures 2.5m x 1.25m x 3.5m in dimension with two recharge bores, each 150mm in diameter and 20m deep. The recharge well is filled with three layers of pebbles ranging from 10mm to 100mm in size, which act as filtering media.
Surface runoff harvesting:
The rooftop rainwater and surface runoff from the paved and unpaved areas in the colony are collected in a series of interconnected collection chambers. This water is harvested by converting the 116 collection chambers into percolation pits by drilling a recharge bore of 100mm diameter and 15m deep. The quality of runoff water through these recharge bores is ensured through a filter media.
The implementation was completed on July 2001, and the water level on February 2003 was recorded at 39.6 m below ground level (bgl).
The cost of the entire rainwater harvesting system was Rs 5.9 lakh.
Water level data
This project showed it was possible to minimise water logging in colonies through rainwater harvesting. The roads of Garden Estate became waterlogged even after a short shower. The water level was recorded at 39.6m below ground level (bgl) in April 2003. Concerned with declining water tables and water logging, the Garden Estate Resident Welfare Association decided to adopt rainwater harvesting throughout the colony. After the successful implementation, the problem of water logging has been solved and the water level recorded in July 2003 was 37.9m (bgl), showing a net rise of 1.7m, or 5.57 feet.