Potential Areas and Availability of Unsaturated Zone for Recharge: Any man-made scheme or facility that adds water to an aquifer system may be considered to be an artificial recharge to ground water. It may be planned as in the case of a pit that has been dug for the purpose of putting water into an aquifer, or it may be unplanned or incidental to human activity in the case of surface water irrigation. The pre-requisites for undertaking artificial recharge to ground water are:

1. Favourable hydrological set-up.
2. Developed aquifers.
3. Availability of unpolluted surface water.
4. Ground water dependent community.

Based on the above criteria, artificial recharge to ground water in South and South west district needs to be given top priority so as to make the ground water resources sustainable and improve the quality which is deteriorating because of over-exploitation. Thickness of unsaturated zone in Tughlaqabad, Okhla, Khanpur, Pushp Vihar, Sainik Farm, Saket, Mehrauli and surrounding areas of Gadaipur, Jaunapur and Ghitorni villages of South district varies from 45 to 50 m. In areas like Greater Kailash- I & II, Chittaranjanpark, Green Park, Lado Sarai and surrounding areas the thickness of unsaturated zone is about 25 m. Vasant kunj, Vasant Vihar, Samalkha and Rajokri areas of South west districts have unsaturated zone thickness ranging from 35 to 45 m. The Central part of South west districts have unsaturated zone of 12 to 15 m. Thus, very potential unsaturated aquifer system is available in these two districts shows that, more and more areas are becoming brackish to saline because of exhaustion of fresh ground water present at shallow depths and upcoming of brackish water into fresh water aquifers.

Soil Classification & Distribution
The soils of the Delhi area are mostly light with subordinate amount of medium texture soils. The light texture soils are represented by sandy, loamy, sand and sany loam; whereas medium texture soils are represented by loam silty loam. Textural classes of soils as revealed from the grain size analyses of 313 soil samples, carried out by Messere Radio Foundation Limited and Hazard & Co., Bombay for the Metropolitan Project of Delhi area(Railway), are shown in Plate - III. The soils that occur in all the blocks are generally suitable for irrigating moderately salt resistant crops such as wheat, barley and mustard.