Despite installing 37 sewage treatment plants (STPs) capable of handling up to 100 per cent of the city’s sewage and connecting 80 per cent of areas to sewer lines, the capital’s primary river remains biologically dead in many stretches. A new report now reveals that the capital’s efforts have been more cosmetic than structural, urging a complete reimagining of how Delhi approaches river clean-up. According to a fresh assessment released by a reputed environmental think tank, the 22-kilometre stretch of the Yamuna in Delhi  just 2 per cent of the river’s total length contributes over 80 per cent of the total pollution load. In most months of the year, what flows through the Yamuna in Delhi is not river water but untreated sewage from 22 city drains. From Wazirabad onwards, the river is essentially a sewer a fact that not only threatens water security in the capital but also for cities downstream that rely on this river for basic needs.

Despite the city’s 37 STPs, nearly two-thirds do not meet Delhi’s own stricter effluent discharge norms, set at 10 mg/l. The water, post-treatment, is discharged into polluted drains where it mixes with untreated effluents from unsewered colonies and desludging tankers. This undermines any gains made from the expensive sewage treatment process. Moreover, only 10 to 14 per cent of the treated wastewater is reused, suggesting that most of the cleaned water either returns to pollute the river again or is simply wasted. The new report outlines a five-pronged corrective agenda. Foremost among these is the urgent need to regulate desludging tankers, many of which dispose of untreated faecal matter directly into drains. Monitoring these tankers through GPS and ensuring that all sludge is taken to STPs is being pitched as a faster and cost-effective alternative to building new pipelines. Another key area is preventing the treated water from being discharged into drains already carrying untreated sewage. Instead, authorities must plan decentralised reuse of treated wastewater for horticulture, cooling, or industrial processes.

A major weakness exposed by the report is the lack of comprehensive data on Delhi’s total wastewater generation. The absence of updated population data and accounting for unofficial water sources like tankers or borewells has meant that the city is working with estimates rather than precise figures. Without this foundational information, efforts to clean the river remain directionless and largely ineffective. Two of the biggest contributors to the Yamuna’s pollution  the Najafgarh and Shahdara drains   continue to spew untreated waste into the river despite heavy investments under the interceptor sewer project. These two drains alone account for 84 per cent of the pollution load, yet continue to operate with outdated plans. The report demands an immediate rethink, pointing out that money spent on failing strategies only leads to public distrust and environmental degradation.

Delhi’s tryst with river rejuvenation is a mirror to broader urban failings  ambitious budgets, fragmented execution, and absence of long-term thinking. Unless governance frameworks shift from infrastructure-led optics to systemic regulation, Yamuna’s decay will remain a living testament to the city’s environmental apathy. In a metropolis that seeks to be world-class, a dead river running through its heart is not just unsustainable  it is unacceptable.