For Chennai, long accustomed to counting water supply by the hour and anxious over summer scarcity, water stress is a subject of both concern and dark humour. The city’s experiment with a 24-hour uninterrupted and equitable piped water supply — aided by a ring main distribution system, a looped pipeline network linking all sources — signals a move away from intermittent distribution and short-term water management.
Chennai is sustained by its water sumps. This perpetuates the myth that piped supply is continuous, when in reality it is not. Even the key areas get only intermittent supply, which makes the Adyar zone trial a key experiment that may change the city’s water distribution strategy. Continuous piped supply in this zone is set to be initiated at a time of comfort in the city’s daily water distribution this year. Chennai’s major reservoirs have better storage than ever in recent years. This gives the planners breathing space to focus on improving reliability rather than managing sparse resources and rationing.
Calibrated water release
The calibrated water release strategy of the Water Resources Department — factoring in rainfall, inflow, and demand — has helped to optimise reservoirs’ storage, supported by the steady transfer of water from Krishna River in Andhra Pradesh and from the Veeranam Tank in Cuddalore district. At the heart of the ₹271.50-crore pilot project in Zone XIII is an attempt to break Chennai’s long-standing dependence on time-bound supply schedules that has led to uneven distribution across areas. The initiative aligns with the vision of the Union Ministry of Housing and Urban Affairs to make Indian cities water secure through Atal Mission for Rejuvenation and Urban Transformation (AMRUT) 2.0.
The Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) is finalising tenders to appoint a concessionaire to upgrade the Pallipattu and Thiruvanmiyur water distribution stations. The upgrade, to be completed in two years, will include improving distribution pipelines, automated controls, and SCADA-enabled real-time monitoring. These measures are critical for continuous, metered supply, and for maintaining stable pressure to prevent pipeline contamination. The water agency has entered into an agreement with the Water Corporation of Odisha, which implemented ‘Drink from Tap Mission’ in Puri, to serve as a project management consultant.
According to the World Bank, the round-the-clock supply is being implemented, or is under execution in various other States, including Karnataka, Madhya Pradesh, Andhra Pradesh, Punjab, and Maharashtra. In Tamil Nadu, pilot projects are under way at a few other places, including Coimbatore and Tiruchi. However, Chennai residents see the promise of uninterrupted supply with cautious optimism. The city has long relied on a mosaic of sources — groundwater and Metrowater supply, tanker, and increasingly packaged drinking water — to bridge the persistent gaps. Chennai and its neighbourhood consume 2-3 crore litres of packaged water daily.
Welcoming the move, residents insist on distribution of clean water and an accountable, sustainable supply. At Adyar, residents say continuous supply will help save the groundwater reserves. Chennai’s average groundwater level has dipped marginally by 0.70 metres in December 2025, compared with the previous year, as the northeast monsoon this season was marked by prolonged dry spells.
R. Krishna Mohan, a Besant Nagar resident of more than five decades, points to the strain that rapid urbanisation has placed on the groundwater table. “Having lived here since 1972, I’ve seen a once-abundant coastal aquifer move to severe stress owing to over-extraction. Water-metering and regulation of borewells are critical to reduce wastage, plan for shortages, and protect what remains of the coastal aquifer,” he says.
Ageing pipelines
Concerns over ageing infrastructure and water quality persist even in the core parts of the city. Though complaints about supply disruptions have come down, sewage pollution and issues caused by old pipelines pose a serious threat. S. Gopi, secretary, Kodambakkam Subramanian Nagar Residents’ Welfare Association, says efforts to improve supply would fall short unless contamination risks are addressed. “Our locality has faced several instances of sewage mixing in drinking water in the four years since the storm water drains were built. Improperly aligned pipelines caused a drop in water pressure in the tail-end areas.”
Before moving to the next stage in its strategy and installing water meters, Metrowater must ensure that households get clean water, residents say. Replacing the old lines and preventing sewage from entering storm water drains are imperative if continuous supply is to succeed.
In its guidelines for uninterrupted supply, the Ministry of Housing and Urban Affairs has highlighted the significance of continuous pressurised supply to people’s health and improving the deteriorating water quality. It has noted that contaminants can enter pipelines through leaks in intermittent water supply during non-supply hours owing to the vacuum developed in the pipeline.
Source augmentation is no longer a major constraint. The focus has shifted to equitable supply, demand management, and increasing use of recycled water to build water resilience, says CMWSSB Managing Director T.G. Vinay.
The upcoming fourth desalination plant at Perur, with a capacity of 400 million litres a day, the recently commissioned second line from the Chembarambakkam treatment plant to enhance distribution, the new reservoir in Thiruporur, and the expansion of the recycled water capacity will strengthen Chennai’s water supply base, say officials. Metrowater has estimated in its master plan that water demand is likely to increase to 1,762 mld by 2057.
In the next five to 10 years, Chennai can put its annual fear of monsoon failure behind and move to a dependable, rationalised water supply. A network of decentralised water treatment plants, including those at Perungudi, Kolathur, and Mogappair, is being built to meet the growing demand. The drinking water potential of lakes such as Porur and Ayanambakkam is being tapped, says Mr. Vinay. The major challenge is the ageing water distribution infrastructure, and this will be addressed in phases.
Controlling leaks
In the Adyar zone, the entire distribution network will be divided into district-metered areas by fixing boundary valves and flow meters to control leaks, reduce the supply of non-revenue water, and balance the pressure across the network.
The pilot project in core areas, including in two wards of Valasaravakkam, was initiated in accordance with the mandates of the Japan International Cooperation Agency, which funds the Perur desalination project. SMEC International, the project management consultant for the new desalination plant, is preparing a detailed project report for the other zones covering core areas, including Tondiarpet, Perambur, and Teynampet.
Residents of Manali New Town point out that the quality of piped water supply has improved after new lines were laid six months ago. P.K. Thenkanal Isaimozhi of Manali New Town says the groundwater is available at a depth of 30 feet. But households largely rely on Metrowater’s three hours of daily supply.
“Water demand will increase as more apartments come up in the area. Metering will help assess consumption, but Metrowater must create awareness to allay fears of over-billing when the system shifts to metered tariffs,” Mr. Isaimozhi says.
Metrowater officials say the uninterrupted water supply will be expanded to all core areas in phases. The water agency is pursuing parallel initiatives to achieve its goal of converting Chennai into a water-secure city. The 98-km circular pipeline, or ring main distribution system, will interconnect all water sources with distribution points to ensure water availability to all areas even if one source fails. The entire water distribution network will undergo a revamp once the ₹3,108.55-crore ring main distribution system and 24/7 water supply projects are implemented.
As for the demand, Metrowater is targeting one lakh water-intensive users to install smart water meters, and metering will be expanded to domestic consumers in phases. Installing electromagnetic flow meters with Internet of Things (IoT) technology in water treatment and distribution network would go a long way in identifying leaks and reducing non-revenue water supply, said officials.
Sewage management
Water experts have called for the creation of a unified water management authority, on the lines of the Chennai Unified Metropolitan Transport Authority, empowered to manage fresh and recycled and storm water in an integrated manner. They argue that a fragmented approach often hinders effective planning and accountability.
B. Sakthivel, a hydrologist and consultant who works with government agencies, says lasting improvements to drinking water sources and infrastructure would be possible only when the entire sewage loop — generation, collection, and treatment — is closed. The State government must also fix key performance indicators for sewerage management for utilities to ensure measurable outcomes.
