The Delhi government recently told the high court that it was considering the implementation of roofwater harvesting in the residential and non-residential buildings of Delhi, which have an area of 100 square metre or more. The information was passed on during a hearing of a public interest litigation filed by TAPAS, a Delhi-based non-governmental organisation, regarding the water crisis in Delhi. In a previous hearing of the petition, the court had taken a strong stand regarding the government's failure to protect the city's waterbodies from encroachment as well as pollution.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/watery-problem
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/down-earth
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-harvesting
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/public-interest-litigation-pil
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/legislation
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/high-court
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/ngo
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi