Tambaram’s 24×7 Water Plan Must Solve the Water Balance Before the PPP

Tambaram is examining whether private participation can help transform six rapidly urbanising neighbourhoods from intermittent water supply to round-the-clock distribution.

That is a significant infrastructure proposal.

But the decisive question is not who operates the pipes.

It is whether enough dependable water enters the system, whether distribution losses are brought under control and whether consumers receive affordable service at measurable pressure and quality standards.

Tamil Nadu Urban Infrastructure Financial Services Limited has invited consultants to revise a detailed project report originally prepared in 2023 for Sembakkam, Madambakkam, Chitlapakkam, Thiruneermalai, Perungalathur and Peerkankaranai.

The new DPR is expected to incorporate updated population, development, infrastructure, demand and cost assumptions and recommend a suitable public-private partnership model. The proposed service architecture includes a district-metered 24×7 distribution network extending from treatment plants or bulk supply points to consumers.

That is a planning decision.

It is not yet a concession.

Tambaram’s problem begins before the distribution network

The corporation’s water system depends on several sources, including supplies from the Tamil Nadu Water Supply and Drainage Board and Chennai Metro Water. The existing system remains characterised by intermittent supply, low pressure and inadequate per-capita availability.

In June, councillors complained that basic water shortages persisted four years after Tambaram became a corporation.

Officials said the city required approximately 130 MLD but was receiving around 90 MLD. One councillor reported that residents in her ward were receiving water on alternate days for only around 15 minutes.

That is the first constraint a 24×7 project must confront.

A distribution network cannot supply water continuously if its dependable bulk input is insufficient.

The revised DPR should therefore begin with a transparent source-to-consumer water balance:

source availability → treatment → bulk transmission → storage → distribution input → leakage/non-revenue water → billed consumption

Every number should be reported for:

• average year;
• dry year;
• peak summer;
• and emergency outage conditions.

Without that, “24×7” remains an operating aspiration rather than a bankable service standard.

The six areas already have a large infrastructure proposal

A ₹500-crore drinking-water project for these same six areas was reported in July.

The project was described as serving more than four lakh residents through:

• new transmission mains;
• distribution networks;
• overhead reservoirs;
• three pumping stations of 5 MLD each;
• household service connections;
• bulk meters;
• consumer meters;
• pressure-management systems;
• and SCADA monitoring.

Those components are exactly what a continuous-supply system normally requires.

The new PPP exercise therefore needs to answer a basic accounting question:

Is the infrastructure design changing, or only the delivery and operating model?

If the ₹500-crore scheme and the revised PPP DPR concern the same core network, the public should receive one consolidated project statement showing:

• original 2023 estimate;
• July 2026 estimate;
• revised PPP estimate;
• scope changes;
• financing changes;
• and reasons for moving towards a private-participation model.

Otherwise, the same project can appear in the public record as multiple separate initiatives.

Tambaram already has a smaller 24×7 experiment

The city is not beginning from zero.

Official corporation records show a ₹20.29-crore project to provide 24×7 water in pilot zones.

Its financing is unusually transparent:

This pilot is strategically important because it can establish local evidence on:

• leakage reduction;
• required network pressure;
• household consumption;
• meter performance;
• energy costs;
• billing;
• complaint volume;
• supply continuity;
• and willingness to pay.

Before Tambaram signs a long-duration PPP, the pilot results should be published.

A city should not scale a service model before demonstrating how it performs locally.

PPP is a delivery model—not the public-service objective

Public debate often collapses water PPPs into two opposing claims.

One side assumes private participation will automatically deliver efficiency.

The other assumes any private role means the water resource itself has been sold.

Neither is technically precise.

A PPP can take many forms.

A private operator may be asked to:

• design and construct infrastructure;
• rehabilitate existing pipes;
• operate treatment plants;
• manage pumping;
• maintain the network;
• install meters;
• reduce non-revenue water;
• handle billing;
• collect revenue;
• or perform some combination of these.

The municipality can still own the assets, control water allocation and regulate tariffs.

The decisive issue is therefore the contract.

Tambaram must disclose exactly which powers remain public and which responsibilities transfer to the concessionaire.

Salem demonstrates why contract language matters

Tamil Nadu already has a live comparison.

SUEZ announced in February that it had won a 25-year concession for Salem covering design, rehabilitation, construction and operation of the city’s water system. The contract specifies performance indicators including continuous supply, progressive reduction in non-revenue water, complaint resolution, metering, billing and water-quality compliance. Existing and new assets remain municipally owned.

The Salem project later generated substantial political controversy over private participation. Yet the State subsequently confirmed a formal agreement had been signed with SUEZ and revised the infrastructure project cost to ₹1,035.61 crore.

For Tambaram, the lesson is not that Salem’s model should automatically be copied or rejected.

It is that the concession structure must be public before the political argument begins.

Coimbatore shows both potential and delivery risk

Coimbatore provides a second relevant precedent.

Its large 24×7 programme, also implemented with SUEZ, had reached around 97% completion by June 2026 after beginning in 2018 and experiencing repeated delays.

Reported operating improvements in parts of the network include reduced water losses and stronger revenue collection.

But the programme also produced repeated road excavations and construction-management problems. Coimbatore Corporation fined the contractor for poor road restoration, while residents previously complained about unauthorised requests for extra connection payments.

Tambaram therefore has useful evidence available before finalising its contract:

performance-based private operation can improve network efficiency, but construction disruption, customer protection and accountability require explicit safeguards.

Continuous water is fundamentally a pressure-management reform

Intermittent systems operate differently from continuously pressurised systems.

When a network receives water for only a short period, households often:

• install underground sumps;
• pump aggressively;
• store large quantities;
• compete for pressure;
• and depend on tankers when supply fails.

Continuous supply attempts to replace that behaviour with stable pressure and predictable service.

To make this work, Tambaram needs district-metered areas.

Each DMA should have measurable:

• inflow;
• pressure;
• household consumption;
• leakage;
• minimum nighttime flow;
• water quality;
• and service interruptions.

That allows operators to identify where water is disappearing.

A citywide supply number cannot reveal whether one neighbourhood is losing 40% of its water before it reaches consumers.

Non-revenue water should be the PPP’s main performance metric

The private operator should not be paid simply for maintaining pipes.

Its contract should reward measurable improvements.

At minimum:

1. non-revenue water;
2. continuity of supply;
3. minimum and maximum pressure;
4. water-quality compliance;
5. meter accuracy;
6. complaint resolution;
7. pipe-break frequency;
8. energy consumption per kilolitre;
9. customer-connection coverage;
10. restoration time after failures.

The strongest PPP would connect operator compensation to these outcomes.

The weakest would guarantee a long payment stream simply for operating infrastructure.

Tariffs require particular scrutiny

Tambaram already has a sensitive tariff environment.

The corporation raised monthly water charges from ₹50.50 to ₹150.50 from April 2026, prompting objections from residents who argued that charges had risen even while supply remained irregular.

The World Bank-supported TNCRUDP framework expects participating ULBs implementing 24×7 projects to move towards legally notified volumetric water tariffs.

That creates a necessary policy debate.

Metering is essential for:

• detecting leakage;
• discouraging wastage;
• measuring actual consumption;
• and operating a continuous-pressure system.

But metering must not make basic household water unaffordable.

Tambaram should publish a tariff framework before PPP tendering, including:

• lifeline consumption block;
• domestic tariff slabs;
• commercial and industrial tariff;
• connection charge;
• meter charge;
• minimum bill;
• subsidy for vulnerable households;
• disconnection safeguards;
• and independent appeal procedures.

A concessionaire should not possess unilateral tariff-setting power.

24×7 should not mean “water whenever you can pay”

Reliable water is a public service.

The customer-protection framework must therefore apply regardless of operator model.

There should be guaranteed procedures for:

• incorrect bills;
• defective meters;
• disputed consumption;
• low pressure;
• unsafe water;
• service interruption;
• unauthorised disconnection;
• and emergency household supply.

Tambaram’s citizen charter already provides time limits for drinking-water complaints, including repairs to main pumping, service connections and pollution complaints.

A PPP should strengthen—not replace—those municipal accountability obligations.

Water and sewerage need to be planned together

The six proposed water areas overlap heavily with Tambaram’s most serious sanitation gaps.

Chitlapakkam, Sembakkam and Madambakkam are covered by a proposed 267-km underground sewerage network and a 35-MLD treatment plant intended partly to prevent sewage entering Madambakkam Lake.

Administrative sanction was given for the approximately ₹585-crore sewerage project, although tender processing was interrupted earlier this year by the election Model Code of Conduct.

This sequencing matters.

Continuous water supply increases the volume of wastewater that must be safely collected and treated.

A household receiving reliable piped water while still depending on a septic tank or leaking local drain can intensify sanitation pressure.

The six-area planning framework should therefore align:

water connection → household consumption → sewer connection → sewage conveyance → treatment capacity → safe discharge/reuse

That is what an integrated urban-water system looks like.

Climate resilience requires source diversification

The World Bank’s TNCRUDP climate assessment identifies Tamil Nadu’s participating ULBs as facing high to extreme water risk and specifically flags Tambaram among cities exposed to significant water-related climate hazards.

This means 24×7 supply cannot depend entirely on better pipes.

The long-term plan needs:

• dependable regional bulk supply;
• desalination where viable;
• local lake and aquifer protection;
• rainwater harvesting;
• treated-wastewater reuse;
• leakage reduction;
• demand management;
• and drought contingency arrangements.

Continuous water distribution should make Tambaram more resilient to drought—not merely more dependent on an increasingly stressed bulk source.

What Tambaram should publish before selecting a private operator

The revised DPR should become a public document.

It should disclose:

The public-interest test

Tambaram unquestionably needs better water infrastructure.

The corporation was created partly because its rapidly urbanising municipalities and town panchayats required integrated water, sewerage and civic systems.

The six localities now proposed for 24×7 supply are precisely among the areas where that infrastructure transition remains incomplete.

A performance-based PPP could potentially accelerate that transition.

But it will only deserve the term 24×7 water reform if four conditions are met:

enough water enters the system;
less water is lost;
every household receives measurable service;
and tariffs remain publicly accountable and affordable.

The operator model is secondary.

The public outcome is a tap that delivers safe water at reliable pressure every day—without forcing residents to buy the reliability back from tankers.