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: 4 Jun 2026, 03:54 pm
Live reservoir storage, refill rates, monsoon catchment context, and the urban supply chain that draws from them.
See live data on dashboard→Reservoir storage today
Chennai's six combined reservoirs hold 7,347 MCFT of water today - 55.6% of total capacity (13,222 MCFT).
Today vs 2019 Day Zero
Chennai's reservoirs today (7,347 MCFT) hold 7,328 MCFT higher than the ~19 MCFT of usable storage when reservoirs were effectively dry on 19 June 2019.
Desalination capacity and status
Minjur (100 MLD, since 2010) and Nemmeli (100 MLD) represent 200 MLD of installed desalination capacity - roughly 20% of Chennai's piped supply when both plants run at full capacity. Operating output varies: CMWSSB has cut Nemmeli production during periods of high reservoir storage (TNIE, Feb 2026).
Total reservoir capacity
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.
Piped supply vs demand
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.
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.
See full data sources →