Following the July 2005 deluge, all plastic bags below 50 micron and smaller than 8x12 inches were banned across the city.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/rewind-plastics-continue-clog-nullahs-across-mumbai
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/indian-express-mumbai
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/maharashtra
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/mumbai
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/plastics
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/non-biodegradable-wastem
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/waterlogging
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pollution