Mumbai River Gets 40x Cleaner With New Treatment Plants

The Dahisar River in Mumbai hasn't run clean in decades, but two new sewage treatment plants just changed that in a big way.

The 17.4 kilometer river flows from Sanjay Gandhi National Park through densely populated north Mumbai neighborhoods before emptying into the Arabian Sea. For years, untreated sewage and waste from homes and businesses turned the water black with pollution.

That's now changing. On May 10, Mumbai officials inaugurated two sewage treatment plants that catch polluted water before it enters the river, clean it, and then release it. The results are dramatic: water quality measurements show the river is now 40 times cleaner than before.

The larger plant treats 5 million liters of sewage daily, while the smaller one handles 1.5 million liters. Together, they act as barriers preventing dirty water from flowing directly into the river. The project cost about $29 million and represents the first phase of a complete river restoration plan.

The Ripple Effect

The cleanup could transform how Mumbai residents experience this historic waterway. Local officials say the next phase will add walking paths along the riverbanks and continue improving water quality to levels that could support boating and eco-tourism.

The river has deep roots in the region's history. It once served as a major transport route for Raja Bimba centuries ago, and Bollywood filmmakers shot movies along its banks in the 1950s. Now, after decades of neglect, it's getting a second chance.

Union Minister Piyush Goyal compared the project to major river restoration efforts for India's Ganga and Sabarmati rivers. "Development is not about building infrastructure only," he said at the inauguration. "Protecting the environment is also a key part."

The transformation began after India's National Green Tribunal ordered Mumbai's civic body to develop a rejuvenation plan in 2020. Local officials responded with this two phase approach, starting with stopping pollution at its source.

Generations of Mumbai residents have only known the Dahisar as a polluted stream cutting through their neighborhoods. Soon, they might know it as a clean waterway where families can walk, boat, and reconnect with nature right in their city.