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: 19 Apr 2026, 03:28 pm
Live numbers from daily monitoring feeds. Each card shows its data cadence and timestamp.
Reservoir storage today
Chennai's six combined reservoirs hold 9,560 MCFT of water today - 72.3% of total capacity (13,222 MCFT).
Today vs 2019 Day Zero
Chennai's reservoirs today (9,560 MCFT) hold 9,541 MCFT higher than the ~19 MCFT of usable storage when reservoirs were effectively dry on 19 June 2019.
Water body area change (year-over-year)
Across 12 tracked water bodies with sufficient data, comparing the most recent 6 months against the same 6 calendar months of the previous year yields a net -86.8 ha change in surface area.
Biggest-shrinking water body (year-over-year)
Retteri Lake's 6-month average surface area is 60.3% smaller than the same 6 calendar months a year earlier - the largest relative decline among water bodies with sufficient seasonal data.
Biggest-growing water body (year-over-year)
Korattur Lake's 6-month average surface area is 58.5% larger than the same 6 calendar months a year earlier. Consistent with restoration, rainfall retention, or seasonal hydrology - causal attribution requires field verification.
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 →