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The Mithi River, once celebrated as Mumbai’s “sweet stream,” is today a stark emblem of urban neglect and pollution. Amid alarming news of floods in Mumbai as the Mithi River nears the danger mark this August, its plight and potential have moved sharply into focus.
From Sweet Waterway to Polluted Drain
Originating from Vihar Lake and Powai Lake, the Mithi River traverses less than 18 kilometers before meeting the Arabian Sea at Mahim Creek. It was once a vibrant lifeline, nurturing fishing communities and dense mangroves. Now, with 100% of its flow classified as sewage since 2015, the contrast couldn’t be starker. In 2020, the Maharashtra Pollution Control Board (MPCB) rated its Water Quality Index at just 41 out of 100, labeling it “heavily polluted.”
- Powai Lake now reports pollution 8 times beyond the safe limit, with water undrinkable.
- At Mahim Creek, the river’s endpoint, aquatic life is virtually unsustainable.
Pollution Crisis—By the Numbers
- Domestic Sewage: 93% of pollution, mainly from Mumbai’s 2 million riverside residents and 1.5 million tenements lacking sewage management. 85% of waste entering Mithi is untreated—resulting in fecal coliform bacteria levels 180 times the standard and the presence of drug-resistant E. coli.
- Solid Waste: Daily, 80–110 metric tonnes of plastic and other debris choke the river. This includes single-use plastics, religious refuse, and liquor bottles.
- Industrial Pollution: 7% comes from over 1,500 industries and 3,000+ illegal setups along its banks. Harmful heavy metals, concrete debris, and chemicals far exceed acceptable limits.
- Eutrophication: Algal blooms, invasive Water Hyacinth, and high biological oxygen demand (BOD over 30 mg/L, ten times the safe limit) suffocate aquatic life.
Urban Importance: Mumbai’s Natural Drain—Now a Flood Risk
The Mithi River is Mumbai’s natural drainage channel—a critical line of defense against flooding. Its decline was tragically evident during the 2005 Mumbai floods, which claimed around 1,000 lives due to reduced flow and surging blockages. Concrete embankments, silt, garbage, and unplanned construction now dramatically reduce Mithi’s flood-carrying capacity.
- Mangroves, Mahim Creek’s natural ‘buffer zone’, have been devastated—impacting both biodiversity and flood safety.
- Health risks soar as waterborne diseases rise near riverbanks, with children especially vulnerable to typhoid, cholera, and long-term exposure to heavy metals.
Economic Toll and the Cost of Neglect
The stench and ruined landscapes reduce property values and disrupt local fishing. Flood-driven property loss and healthcare burdens hit Mumbai’s poorest hardest.
Official and Citizen Action: Turning the Tide
Administrative Response
- The Mithi River Development and Protection Authority (MRDPA) was formed following the 2005 disaster but has been criticized for infrequent meetings and slow progress.
- Regulatory crackdowns have shut or penalized hundreds of illegal and high-polluting industries.
- Sewage Treatment Plants (STPs) have been planned and decentralized, but completion lags behind Mumbai’s ballooning demands.
- Billions of rupees were spent on widening, deepening works, and installing trash booms at several points.
- Pilot Bioremediation Projects: Using Persnickety-713 bacteria, pilot stretches showed improved water quality.
Yet critics note most administrative efforts remain short-term, data-deficient, and often encroach on the river’s vital floodplains—exacerbating, not curing, its ills.
Citizens Lead Restoration
There’s hope in passionate citizen movements:
- Beach Please (Malhar Kalambe’s group) has removed 3,800+ tonnes of trash since 2018. Despite tough conditions, volunteers persist.
- Project Mumbai and Afroz Shah organize cleanups, public awareness drives, and link educational campaigns with reward programs.
- Earth5R’s Sustainable Community Model, with support from international partners, has:
- Trained 10,000 families on waste segregation
- Segregated 1,500 metric tons annually
- Offset 3,750 metric tons of carbon emissions
- Created 150+ sustainable livelihoods, especially for women and ragpickers
- Resulted in a 12% drop in BOD and 9% drop in COD in pilot stretches within 6 months.
- Trained 10,000 families on waste segregation
Path Forward: Long-Term Solutions Needed
Mumbai’s swelling population and runaway urbanization continue to threaten the Mithi. True revival demands:
- Completion and timely expansion of STPs and waste management systems
- Enforcement against illegal encroachment and persistent polluters
- Ecological restoration—regenerating mangroves, restoring floodplains, and integrating nature-based solutions into city planning
- Deep community engagement: promoting “circular economy” waste reduction and rewarding sustainable behaviors
The Mithi’s story is Mumbai’s story—a battle between growth and sustainability. Without sustained collaboration and action from both the government and its citizens, Mumbai’s “sweet waterway” will remain in crisis. But with renewed resolve, science, and community spirit, the Mithi River’s revival is possible—and urgently necessary for the city’s future.
