City Water PictureCityTamil Nadu

Chennai water picture

Water availability is classified as Absolute scarcity.

The official published classification is Absolute scarcity for both 2025 and 2050.

Where supplied water comes from

Not proven from the official evidence currently reviewed.

Groundwater context

Before and after monsoon depth band: 2–5 metres below the ground surface; Exact published band: 2 to 5 mbgl · 2023-24

Latest groundwater-quality evidence

No station-level numeric quality result is published on this page. The reviewed samples do not establish city-wide or tap-water quality.

Official institutions and periods

NITI Aayog; Fifth State Finance Commission, Government of Tamil Nadu

2021-22 · 2022-23 · 2023-24 · 2025 · 2050 · 2017 report using 2015 operating context

This does not establish today’s household supply, pressure, continuity or tap-water safety.

See the full evidence and limitations

Where supplied water comes from

These relationships come from official utility or government publications. JalWater keeps operating, historical, proposed, and unproven evidence separate.

A current operating source relationship is not proven from the official evidence currently reviewed. Historical systems below remain useful context, not proof of today's operating mix.

Historical official relationships

Red Hills (Puzhal)

Historical official evidence · 2017 report using 2015 operating context

Reservoir Lake

The Tamil Nadu Finance Commission report lists Red Hills (Puzhal) among sources from which CMWSSB was then drawing water.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB/Chennai operating context reported for 2015; exact zones are not stated.
Evidence locator: PDF page 180, paragraph 7.20
Limitation: This is historical evidence and does not prove current operation, present storage, source share or household delivery.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Chembarambakkam

Historical official evidence · 2017 report using 2015 operating context

Reservoir Lake

The report lists Chembarambakkam among sources from which CMWSSB was then drawing water.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB/Chennai operating context reported for 2015; exact zones are not stated.
Evidence locator: PDF page 180, paragraph 7.20
Limitation: This is historical evidence and does not prove current operation, present storage, source share or household delivery.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Veeranam

Historical official evidence · 2017 report using 2015 operating context

Reservoir Lake

The report lists Veeranam among sources from which CMWSSB was then drawing water.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB/Chennai operating context reported for 2015; exact zones are not stated.
Evidence locator: PDF page 180, paragraph 7.20
Limitation: This is historical evidence and does not prove current operation, present storage, source share or household delivery.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Cholavaram

Historical official evidence · 2017 report using 2015 operating context

Reservoir Lake

The report lists Cholavaram among sources from which CMWSSB was then drawing water.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB/Chennai operating context reported for 2015; exact zones are not stated.
Evidence locator: PDF page 180, paragraph 7.20
Limitation: This is historical evidence and does not prove current operation, present storage, source share or household delivery.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Poondi

Historical official evidence · 2017 report using 2015 operating context

Reservoir Lake

The report lists Poondi among sources from which CMWSSB was then drawing water.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB/Chennai operating context reported for 2015; exact zones are not stated.
Evidence locator: PDF page 180, paragraph 7.20
Limitation: This is historical evidence and does not prove current operation, present storage, source share or household delivery.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Telugu Ganga project · Telugu Ganga project

Historical official evidence · 2017 report using 2015 operating context

Inter Basin Transfer

The report lists the Telugu Ganga project among sources from which CMWSSB was then drawing water.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB/Chennai operating context reported for 2015; exact zones are not stated.
Evidence locator: PDF page 180, paragraph 7.20
Limitation: This is historical evidence and does not prove current operation, present transfers, source share or household delivery.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Dedicated well fields

Historical official evidence · 2017 report using 2015 operating context

Groundwater

The report states that CMWSSB was then drawing groundwater from dedicated well fields.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB dedicated-well-field context reported for 2015; individual fields and service zones are not identified.
Evidence locator: PDF page 180, paragraph 7.20
Limitation: This is historical system evidence and does not establish current extraction, aquifer identity, neighbourhood supply or safety.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Minjur desalination plant · Minjur desalination plant

Historical official evidence · 2017 report using 2015 operating context

Desalination

The report says the Minjur desalination plant supplemented CMWSSB water availability in the reported period.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB/Chennai supplementary-source context reported for 2015; exact zones are not stated.
Evidence locator: PDF page 180, paragraph 7.20
Limitation: This is historical evidence and does not prove current output, present operating condition, source share or household delivery.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Nemmeli desalination plant · Nemmeli desalination plant

Historical official evidence · 2017 report using 2015 operating context

Desalination

The report says the Nemmeli desalination plant supplemented CMWSSB water availability in the reported period.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB/Chennai supplementary-source context reported for 2015; exact zones are not stated.
Evidence locator: PDF page 180, paragraph 7.20
Limitation: This is historical evidence and does not prove current output, present operating condition, source share or household delivery.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Official proposals — not operating evidence

Perur desalination plant · Perur desalination plant

Official proposal — not operating evidence · Proposed in the 2017 report

Desalination

The report lists a Perur desalination plant under proposed improvements/new projects.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB future-project context as of the report; current project status is not established.
Evidence locator: PDF page 184, Table VII-10 row 1
Limitation: This proves historical proposal status only. It must not be presented as operating or under construction today.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Additional Nemmeli seawater desalination plant · Additional Nemmeli seawater desalination plant

Official proposal — not operating evidence · Proposed in the 2017 report

Desalination

The report lists an additional Nemmeli seawater desalination plant under proposed improvements/new projects.

Authority: Chennai Metropolitan Water Supply and Sewerage Board
Geographic scope: CMWSSB future-project context as of the report; current project status is not established.
Evidence locator: PDF page 184, Table VII-10 row 2
Limitation: This proves historical proposal status only. It must not be presented as operating or under construction today.

Source: Fifth State Finance Commission, Government of Tamil Nadu · Report and Recommendations of the Fifth State Finance Commission. Open official source

Groundwater evidence

Before and after monsoon depth band

2–5 metres below the ground surface

2 to 5 mbgl · 2023-24

Published 2025 classification

Absolute scarcity [<500 m3]

Published 2050 classification

Absolute scarcity [<500 m3]

JalWater preserves the official periods and bands. It does not invent intermediate years or infer a trend.

Current condition and water quality

Current source condition

JalWater has not verified a stable official current-condition feed for this city.

Groundwater-quality samples

Reviewed station records are dated 2021–2023 and do not represent city-wide or municipal tap-water quality. Their numeric values are not published here.

Official sources and limitations

Official publications used

Fifth State Finance Commission, Government of Tamil Nadu
Report and Recommendations of the Fifth State Finance Commission · 2017 report using 2015 operating context
PDF page 180, paragraphs 7.19-7.20; page 184, Table VII-10
Open official source

What is not verified

A current operating city-source relationship is not proven from the official evidence currently reviewed.
No stable official current-condition feed has been verified for this city.
No reviewed evidence establishes today's household supply, pressure, continuity, or tap-water safety.
No reviewed evidence establishes a source share for every neighbourhood or property.
No rainfall or reservoir-status feed is used to change the published classifications.
Groundwater-quality station values are excluded from the public release candidate.

Publication method

JalWater publishes independently written factual summaries with prominent attribution and links to official primary sources. It does not reproduce protected tables, images, long passages, raw datasets, or source documents.

View the core Chennai evidence Compare with another city