This could be yet another Mithi controversy brewing. The Mumbai Metropolitan Region Development Authority (MMRDA) has constructed a temporary road right at the mouth of the river near the Mahim Causeway.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/mmrda-puts-mithi-peril
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/daily-news-analysis-mumbai
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/river-pollution
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/maharashtra
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/mumbai
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/mithi