definition
strict definition
rooftop water tank
A large container on a building's roof for supplying water to its plumbing or fire protection system.
A rooftop water tank is a large container for water which is located on the roof of a building or other structure, and which is designed to supply water to the plumbing system and/or fire protection system by gravity feed.
Rooftop water tanks should be visible above the roofline, and may or may not be in use.
The elevated container supplies water by gravity to plumbing, fire protection, or both. The tank is visible above the roofline and can remain present even when its water-supply function is no longer in use.
