Oogwai Intelligence · Mumbai
On 31 July 2026 Mumbai's seven water-supply lakes held 88.6% of usable capacity — the joint-fullest reading in ten years. That is genuinely good news, and it does not close the city's daily shortfall. Storage and supply are two different problems.
Reading date 31 July 2026 · Page updated 14 August 2026
Part one · Storage
Comparing reservoirs across years only works if you read them on the same date — storage climbs through the monsoon, so a July number and a September number are not the same measurement. Every reading below is taken on 31 July.
| Year | Level | Band |
|---|---|---|
| 2017 | 89.6% | Very high |
| 2018 | 49.8% | Lean |
| 2019 | 82.5% | High |
| 2020 | 34.5% | Lean |
| 2021 | 75.0% | High |
| 2022 | 88.7% | Very high |
| 2023 | 75.5% | High |
| 2024 | 77.2% | High |
| 2025 | 88.7% | Very high |
| 2026 | 88.6% | Very high |
Part two · The gap
A full reservoir is a stock. What the city actually delivers each day is a flow — and that flow has never caught up with demand. Over roughly ten years supply gained about 500 MLD, demand gained a similar amount, and the daily shortfall barely moved.
| Period | Actual supply | Estimated demand | Daily deficit |
|---|---|---|---|
| ~10 years ago2014 – 2016 | 3,400–3,750 | 4,200 | 450 – 800 |
| Current2024 – 2026 | 3,950–4,100 | 4,460–4,665 | 500 – 700 |
| Projected2031 – 2041 | 5,300–6,900 | 6,424–6,900 | up to 2,400 (if unmitigated) |
How to read it
2026 is among the fullest years on record, yet the city still runs a daily shortfall of roughly 500–700 MLD. Storage buys time; it does not add delivery capacity.
2020 finished July at 34.5% and 2018 at 49.8%. Planning that assumes an 88% year is planning for the best case twice a decade, not the normal one.
Demand is projected at 6,424–6,900 MLD by the 2030s. The supply figures for that period are targets attached to projects, not capacity that exists today.
Method & caveats
Every storage figure is the combined useful storage of Mumbai's seven water-supply lakes on 31 July of that year, as a percentage of total usable capacity. Same date, same lakes, every year.
Supply and demand are reported as ranges because published figures vary by source and by month. The charts show the full reported range rather than picking a single convenient number.
The 2031–2041 supply band reflects targeted capacity tied to planned augmentation projects. It is an intention, not committed capacity, and the ~2,400 MLD deficit assumes those projects do not land.
Figures are compiled from published reservoir and civic water-supply reporting. Where sources disagree, the wider range is shown. Corrections are welcome at info@oogw.ai.
