Between 2020 and 2025, Delhi’s installed water-treatment capacity rose from 916 to 961 million gallons per day (MGD), while sewage-treatment capacity increased from 597 MGD in 2020–21 to about 764 MGD by March 2025. Yet these additions have not produced a correspondingly more secure water system. Groundwater extraction remains high, sewage-treatment capacity is underused, and large parts of Delhi remain outside the sewerage network. The problem, therefore, is not infrastructure alone, but whether different parts of the water system function together.
The Gap Between Indicators and Outcomes
Groundwater illustrates the distinction between improved indicators and improved outcomes. The stage of groundwater extraction fell from 101.4 per cent in 2020 to 92.1 per cent in 2025. Yet annual groundwater abstraction increased from about 0.29 billion cubic metres to 0.32 billion cubic metres over the same period. The number of assessment units classified as critical or over-exploited also declined, from 24 of 34 to 21 of 34.
The lower extraction ratio, therefore, does not indicate a comparable reduction in groundwater withdrawal. It partly reflects an increase in the assessed extractable groundwater resource.
Wastewater presents an even clearer capacity-versus-performance problem. As of March 2025, Delhi had about 764 MGD of installed sewage-treatment capacity, but only about 650 MGD was actually treated – roughly 85 per cent of capacity. The Economic Survey attributes part of the gap to incomplete sewer connections and pending restoration of trunk sewers. The constraint is therefore not simply treatment capacity, but the network required to bring sewage to treatment plants. Coverage also remains uneven: only 55 rural villages had been connected to the sewerage network.
Where the System Remains Fragmented
Delhi’s water system cannot be understood within the NCT’s borders alone. The city depends on water supplied through the Yamuna, Ganga and Bhakra-Beas systems, alongside groundwater, so raw-water availability is partly shaped by arrangements outside Delhi’s exclusive control.
Within the NCT, however, Delhi’s own agencies have substantial influence over what determines how efficiently available water is managed: distribution, metering, sewer connections, treatment, reuse, groundwater management and recharge.
These functions are themselves fragmented. The Delhi Jal Board handles water supply and sewerage, while drainage responsibilities are divided across multiple agencies, sometimes with different institutions responsible for different sections of the same drain. Coordination also depends on integrating drainage, land-use and waterbody information across agencies.
The institutional disconnect extends into urban planning. Water availability, sewerage and drainage are not always treated as a single planning question. This creates a risk that new development adds water demand and runoff without these systems being assessed together as part of the same development decision.
Managing for Outcomes
The policy response should therefore shift from adding individual assets to improving system performance.
First, Delhi needs to give effect to existing commitments on metering, groundwater management, reuse and loss reduction. More than 100,000 connections remained unmetered in 2025.
Second, performance should be judged by outcomes—sewage actually treated, households connected, water reused, groundwater replenished and distribution losses reduced—rather than installed capacity alone.
Third, major new developments should demonstrate adequate water, sewerage and drainage arrangements before approval, with responsibility for drainage maintenance clearly assigned.
Fourth, treated wastewater should be developed more systematically as a source for suitable non-potable uses such as industry, horticulture and construction, where demand and infrastructure permit.
Making the System Work
Better internal management will not eliminate Delhi’s dependence on water supplied from outside the NCT, and interstate coordination will remain essential. But external raw-water availability and internal water management are distinct policy problems. Delhi cannot unilaterally control the first; it can, however, do considerably more to improve distribution, treatment, reuse and groundwater management within the NCT.
Delhi’s water challenge is therefore not simply one of scarcity or insufficient infrastructure. It is increasingly a question of integration: whether supply, distribution, sewerage, treatment, drainage, groundwater and urban development are managed as parts of the same system. The next policy challenge is not only to expand capacity, but to make existing and future capacity work together.