In January 2004, Nizamuddin East became one of the first colonies in Delhi to get rainwater harvesting systems (RWH).
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/nizamuddin-easts-11-yr-old-pits-still-work
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/times-india-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-harvesting
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/municipal-corporation
[6] http://admin.indiaenvironmentportal.org.in/thesaurus/national-green-tribunal-ngt
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/centre-science-and-environment-cse
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/drought
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/groundwater-recharge
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-resources