ABSTRACT

The population of the city is continuously increasing. About 55% of the demand is met by groundwater. Such groundwater exploitation has thus exceeded the recharge in most parts of Delhi. The water supply of the city is, therefore, under tremendous stress due to the growing population’s demand of water for various uses. The water table is declining at an alarming rate and if suitable measures to conserve water and recharge the aquifers are not initiated immediately, some of the reservoirs in various parts of Delhi may deplete permanently and the situation might worsen further. A recent report from the United Nations states that about two-thirds of humanity will suffer from a moderate to severe water crunch; this may already be proving true for India (Case, 1981). Hydro-geologically, the entire city of Delhi lies on the Indo-Gangetic plains, which are comprised of undisturbed layers of geologically recent sediments. It is an aggradational plain, built-up from thick alluvium which the Himalayan streams and rivers have brought down during their mountainous courses and have deposited it where they enter the plains. The

city of Delhi is one such area. The thickness of overlying alluvial fill consists of sand, silt and clay in the city is fairly uniform. On the eastern side, the city is flanked by the river Yamuna. along the river, a maximum concentration of groundwater extraction structures constitute the Yamuna well field which is exploited for drinking water supply for the east Delhi township. The entire area that makes up the east Delhi block has saline/brackish groundwater, overlaid with a thin floating layer of freshwater, at a depth ranging from 50 to 100 metres.