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In the Panchsheel colony the first Layer of clay and kankar
extends to depth of 12m below ground level. This is followed by layer
of kankar and silt from 12 to 25m bgl. This is again underlain by
layer of clay and kankar which extends even beyond 40m bgl.
A comparative
study of water level map of 1960 and 2002 shows in Panchsheel colony
the water level which was at 5 to 10m bgl has gone down to 20 to 30
mts bgl.
In
Panchsheel colony fresh water occurs at all depths.
IV.CASE STUDIES
PANCHSHEEL PARK |
RAINWATER AVAILABLE FOR HARVESTING Total rooftop and surface area
3,57,150 square metres (sq m)Average annual rainfall in Delhi 611
millimetres (mm)Total volume of rainwater harvested: 1,74,575 cubic
metre (m³), or 174,575,000 litres This represents 80 per cent
of the total water harvesting potential
WATER SUPPLY SOURCE
The water supply is mainly through six borewells. Three each are owned
by the Panchsheel Cooperative Group Housing Society and the Delhi
Jal Board respectively. The remaining water requirements are met by
individual borewells.
RAINWATER HARVESTING SYSTEM
Rooftop rainwater and surface runoff harvesting: A network of stormwater
drains in the entire residential area is used for harvesting rooftop
rainwater and surface runoff. About 36 Recharge wells measuring 1m
x 1m x 2m are constructed in the stormwater drain for facilitating
groundwater recharge. The quality of runoff, which passes through
a 15m borewell installed inside the recharge well, is ensured through
a filter bed of pebbles. The project was implemented in June 2002.
The cost of the entire rainwater harvesting system was Rs 8 lakh.
| V.RECOMMENDATION FOR AUGMENTATION
OF GROUNDWATER |
In this area the rainwater can be diverted to a depth of
15 to 20mts bgl. By doing this the rainwater will under go a natural
filtration in the subsoil before it reaches the main aquifer. The
recharge bore in the recharge well should be of 15 to 20mts bgl.
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