Chennai Water Facts

Chennai's water state in quotable numbers. Every fact has a source, a date, and a methodology link. Organised by freshness: today's live data, this year's government releases, historical milestones, and structural infrastructure.

Last updated: 15 Nov 2026, 08:58 am

Historical milestones (Day Zero, the 2015 floods, and similar narrative anchors) are covered as story prose in Chennai's Origins long-read →

Live reservoir storage, refill rates, monsoon catchment context, and the urban supply chain that draws from them.

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Livesupply
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Reservoir storage today

5,682MCFT (43.0% of 13,222 MCFT)

Chennai's six combined reservoirs hold 5,682 MCFT of water today - 43.0% of total capacity (13,222 MCFT).

CMWSSB daily lake level scrape-As of 13 Nov 2026
Livesupply
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Today vs 2019 Day Zero

5,663MCFT higher than 2019 Day Zero (~19 MCFT)

Chennai's reservoirs today (5,682 MCFT) hold 5,663 MCFT higher than the ~19 MCFT of usable storage when reservoirs were effectively dry on 19 June 2019.

CMWSSB daily + 2019 archive-As of 13 Nov 2026
Structural - 2026supply
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Desalination capacity and status

350 MLD installed- operating output varies

Minjur (100 MLD, since 2010), Nemmeli I (100 MLD, since 2013) and Nemmeli II (150 MLD, since February 2024) make up 350 MLD of installed desalination capacity (our sum of the three plants), about 21% of 1,687 MLD, our sum of the eight plant capacities (5 water treatment plants, 3 desalination plants) in the ADB IEE (March 2026). CMWSSB's Contingency Plan 2026 and the MAWS Policy Note 2026-27 count Nemmeli I at 110 MLD, 360 MLD in all. Operating output varies: CMWSSB took over Minjur's operation on 1 April 2025 and is refurbishing it in phases towards an interim 20 MLD (MAWS Policy Note 2026-27), and has cut Nemmeli production during periods of high reservoir storage (TNIE, Feb 2026).

350 MLD is our sum: Minjur 100 + Nemmeli I 100 + Nemmeli II 150. MAWS Policy Note 2026-27, pp.194-197 (Minjur 100, Nemmeli II 150, Minjur status, Nemmeli I at 110); CMWSSB water supply page, last reviewed 18-03-2024 (Nemmeli I 100); CMWSSB Contingency Plan 2026, p.2 (Nemmeli I at 110); ADB IEE, March 2026 (plant capacities, our sum 1,687 MLD); TNIE Feb 2026 (operating status)-As of 21 Aug 2026
Structural - 2026supply
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Total reservoir capacity

13,222MCFT

Chennai's 6 storage reservoirs (Poondi, Cholavaram, Red Hills, Chembarambakkam, Kannankottai-Thervoy Kandigai, Veeranam) have a combined capacity of 13,222 MCFT (approximately 374 million cubic metres) per the CMWSSB lake level page as of April 2026.

CMWSSB lake level page-As of 19 Apr 2026
Structural - 2024supply
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Piped supply vs demand

~1,040 vs 2,232MLD

CMWSSB delivers approximately 1,040 MLD against an estimated city demand of 2,232 MLD - a ~52% gap filled by groundwater extraction, desalination, and the ~15,000-tanker informal water market.

CMWSSB + academic estimates-As of 1 Jan 2024

Methodology & sources

Every number on this page is sourced from a publicly available dataset or official release. Live figures are refreshed daily from government monitoring feeds; annual figures show their vintage year; historical and structural figures are reference data with dated provenance.

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