It is a multipurpose project, which would also provide irrigation and drinking water facilities to Delhi and other northern states such as Rajasthan, Haryana and UP.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/drinking-water-project-quench-dehraduns-thirst
[2] http://admin.indiaenvironmentportal.org.in/category/author/shishir-prashant
[3] http://admin.indiaenvironmentportal.org.in/category/newspaper/business-standard-new-delhi
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rajasthan
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/haryana
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/uttar-pradesh
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/irrigation
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/drinking-water
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/uttaranchal-uttarakhand
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/lakhwar
[12] http://admin.indiaenvironmentportal.org.in/category/thesaurus/yamuna
[13] http://admin.indiaenvironmentportal.org.in/category/thesaurus/planning-commission
[14] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-water-commission-cwc
[15] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dehradun-t