Tihar Jail's Rainwater Harvesting System

RAINWATER AVAILABLE FOR HARVESTING

Total area (Ward 1 and Ward 13): 4125 square meters (Sq m)

Average annual rainfall in Delhi: 611 millimeters (mm)

Total volume of water harvested: 1280 cubic meter (m³) or 12,80,000 litres

This represents 50.78 per cent of total rainwater harvesting potential.

WATER SUPPLY SOURCE
Water supply in these wards is fulfilled by two borewells located inside the jail premises.

RAINWATER HARVESTING SYSTEM

Rooftop rainwater and runoff from unpaved areas:

Ward 1
In Ward 1, the rooftop rainwater from the barracks and the surface runoff from the unpaved area are collected in a low-lying area between the buildings. This water is collected by a collection chamber measuring 0.5m x 0.5m x 0.5m, which is covered by a perforated RCC slab. The water collected in the chamber is diverted to recharge well measuring 1m x 1m x 2m with a recharge bore of 150mm diameter and 10m deep. The recharge well is filled with layers of pebbles and coarse sand, which act as filtering media to improve the quality of the water harvested.

Ward 13
The rooftop rainwater from the buildings and the surface runoff from the open areas are collected in a low-lying area located at southwest corner of the ward. This water is collected in a collection chamber measuring 0.5m x 0.5m x 0.5m, which is covered by a perforated RCC slab. The water collected in the chamber is diverted to a recharge well measuring 1m x 1m x 2m in size with a recharge bore of 150mm diameter and 10m deep. The recharge well is filled with layers of pebbles and coarse sand, which act as filtering media to improve the quality of the water harvested.

The implementation was completed in November 2002 and the water level on February 2003 was recorded at 9.40m below ground level (bgl).

The cost of the entire rainwater harvesting system was Rs 0.2 lakh

IMPACT

Water level data

Thsi project demonstrated that rainwater harvesting can help solve the problem of water logging. Tihar Jail's barracks used to remain flooded for hours after every rainfall. The water level in the jail was 14m below ground level (bgl) in April 2003. Concerned with flooding in the barracks and with sharply declining water levels in the area, the Tihar Jail authorities decided adopt rainwater harvesting in Central Jail No. 4.