Mullaperiyar issue is not a conventional inter-state water dispute as visualised in Article 162 of the Constitution.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/mullaperiyar-dam-case-settlement
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/new-indian-express-kochi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/idukki
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dams
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-disputes
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dam-safety
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/tamil-nadu
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/earthquakes
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/ecology
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/kerala
[12] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dams-irrigation