The average groundwater level in Tamil Nadu has declined considerably in the past five years, with only 4 of 30 districts showing any major increase.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/groundwater-level-state-drops-rapidly
[2] http://admin.indiaenvironmentportal.org.in/category/author/tk-rohit
[3] http://admin.indiaenvironmentportal.org.in/category/newspaper/hindu-chennai
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/tamil-nadu
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/coimbatore-d
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/groundwater
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/tiruppur
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/land-encroachments
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-resources