Fire Water Tank Capacity
Fire water tank capacity is the volume of water a building must store exclusively for firefighting — an underground static tank plus a terrace tank — sized by occupancy, height and built-up area under NBC 2016.
Why it matters on an MEPF project
The static tank is usually the single largest space commitment the fire scheme makes, and it is checked at three separate gates: building-plan sanction, the provisional Fire NOC drawing review, and the final NOC inspection where the inspector physically verifies the tank. Undersizing it is not a paperwork problem — it is a re-excavation problem, discovered after the basement slab is cast.
Capacity depends on occupancy classification and height, not intuition. A warehouse and a hospital of identical footprint carry very different storage obligations, and mixed-occupancy buildings take the most demanding classification. The tank also needs the right suction arrangement, overflow, and dedicated fire-pump connections — volume alone does not pass inspection.
How it's specified in practice
| Parameter | Typical / working position | Governing reference |
|---|---|---|
| Occupancy classification | Residential / business / mercantile / industrial / storage — each with its own schedule | NBC 2016 Part 4 |
| Building height class | Low-rise vs high-rise (15 m threshold) changes systems and storage | NBC 2016 Part 4 |
| Underground static tank | From tens of kilolitres to lakhs of litres by occupancy table | NBC 2016 Part 4 (occupancy tables) |
| Terrace tank | Smaller dedicated volume feeding wet risers until pumps take over | NBC 2016 Part 4 |
Common mistakes
- Sizing the tank from a competitor building instead of the occupancy table — classifications rarely match.
- Sharing the fire tank volume with domestic storage without the mandated exclusivity arrangements.
- Forgetting the terrace tank entirely because the static tank "seems huge".
- Placing the tank where the fire pump suction lift becomes unworkable.
Related on this site
Frequently asked
Can domestic and fire water share one tank?
Only with an arrangement that guarantees the fire reserve cannot be drawn down by domestic use — typically separate compartments or draw-off levels. Many authorities insist on a fully separate fire tank; check your State Fire Service practice before combining.
Who verifies the tank capacity?
The State Fire Service — on drawings at NOC submission and physically at final inspection. The plan-sanction authority also checks it against the bye-laws.
Standards referenced: NBC 2016 Part 4