There are about 73 rain water harvesting(RWH) projects that have been set up in and around Delhi, for about four to five years now yielding tremendous results. A number of case studies prove its
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/rain-rain-come-again-0
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/tehelka-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dams
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/irrigation