A 25% reduction in bore well water consumption annually has been achieved with a good amount of energy savings.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/rainwater-harvesting-system-hindalco-industries-limited
[2] http://admin.indiaenvironmentportal.org.in/category/author/anindya-bhowmick
[3] http://admin.indiaenvironmentportal.org.in/category/journal/everything-about-water
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-harvesting
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/hindustan-aluminium-company-hindalco
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/west-bengal
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-conservation
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment-management