Future Delhi may tap recycled water for toilets, gardens

New Delhi: In the years ahead, turning on a tap in the Capital may no longer mean drawing potable water for daily use. Instead, treated wastewater could be supplied for purposes such as flushing toilets, watering gardens, and supporting industrial operations.

Delhi’s population is projected to reach nearly 30 million by 2041, pushing demand for drinking water to about 1,500 million gallons per day (MGD), up from the current requirement of around 1,250 MGD for an estimated population of 25 million, according to the Economic Survey 2025-26.

To meet the growing challenge, the Delhi Jal Board (DJB) has proposed a shift in water-use policy. The plan envisages cutting per capita potable water supply for future developments to about 40 gallons per capita per day (GPCD), while meeting non-drinking needs — such as toilet flushing, gardening, and industrial use — through treated wastewater supplied via dual-piping systems. The aim is to reserve high-quality water strictly for consumption and rely on recycled water for other purposes.

The survey, tabled on Monday, noted that although Delhi has expanded its water treatment capacity over the years, the increase has not kept pace with demand. DJB’s installed treatment capacity rose by about 21.6% over the past 16 years, from 790 MGD in 2009 to 961 MGD in 2025. During peak summer, the city produces around 1,000 MGD, supported by nearly 15,700 km of pipelines and more than 123 underground reservoirs.

In areas facing shortages, tanker services — about 900 hired and 150 departmental vehicles — continue to supplement supply, the survey said.

At the same time, Delhi govt has maintained its policy of providing free water of up to 20 kilolitres per month to households with metered connections, benefiting nearly 18.9 lakh consumers. About 93.5% of households now have access to piped water supply, reflecting improvements in distribution coverage.

On wastewater management, Delhi generates around 3,632 million litres per day (MLD) of sewage. Treatment capacity has increased sharply, from 402.4 MGD in 2001 to 764 MGD in 2025. At present, about 117 MGD of treated wastewater is reused for irrigation, power plants and other non-potable purposes, with plans to scale this up.

Despite these gains, the survey flagged persistent challenges. Water distribution losses remain above 52%, far higher than global benchmarks, pointing to leakage and inefficiencies. The widespread use of reverse osmosis systems results in 40-60% water wastage, while gaps in sewer connectivity leave around 17-18% of areas outside the network.

To address these issues, DJB has intensified leak detection drives, replaced more than 184 km of old pipelines in 2025-26, installed over 3,000 flow meters for water auditing, and set up a SCADA-based monitoring centre for real-time management. Measures such as GPS tracking of tankers, improved billing systems, and the rollout of the m-Seva app for consumer services are also aimed at improving efficiency and transparency.

The survey attributed higher revenue to a 10% tariff hike for non-subsidised water, expansion of metered connections, a one-time dues clearance window and efforts to plug leakages. Additional revenue measures include renting out properties, tapping solar power, water ATMs and GPS-enabled tanker tracking.

The survey said DJB is now targeting a reduction in non-revenue water losses to about 15% through infrastructure upgrades in key command areas such as Chandrawal and Wazirabad, along with city-wide network improvements. Water quality monitoring has also been strengthened through sampling vans, IoT-based systems at treatment plants, turbidity checks and a microbiological laboratory at Wazirabad, it added.