The http://rainwaterharvesting.org site has a map of Delhi showing geology, water level, water quality and giving recommendations for rainwater harvesting in different areas.
View the map here: http://www.rainwaterharvesting.org/index_files/intro_map.htm
The information may be out of date.
Image source: http://rainwaterharvesting.org
Path Alias
/articles/groundwater-prospects-map-delhi