# Design of underground water tank Underground Water Tank: The size of the reserve tank or underground water tank is based on the number of residents and the time required for complete storage.

Design of Reserve Tank or Underground Water Tank

It is found that each day, one requires 135 liters of water

Every day a person needs 135 liters of water.

Assume, in a day, there exist 27 units in a building and 6 persons in each unit.

Therefore, the total inhabitants in the building = 27 × 6 = 162 people

The amount of water needed for 162 people = 162 × 135 = 21870 liters

Taking into consideration all other things, it is projected to be 1.5 times more water instead the amount of water.

Therefore, the total amount of water = 21870 × 1.5 = 32805 liters Water.

It is known,
1 cft = 6.25 gallons.
And, 1 gallon = 4.53 liters.

Now, for the reserve tanks, the rough length, width and height should have been considered.
Suppose,

Length = 12 ft
Width = 10 ft
Height = 10 ft

Now, the length, width and height should have been multiplied with 6.25 gallons and 4.53 liters.

= 12 × 10 × 10 × 6.25 × 4.53
= 33975 liters
The amount of necessary water = 32805 liters

Water reservoir of 12 × 10 × 10 size reserve tank = 33975 liters
33975 liters is greater than 32805 liters.

Therefore, the size of the tank= 12 × 10 × 10
= 1200 cft.

Video Source: SL Khan