# WATER DEMAND AND WATER TANK SIZE & VOLUME CALCULATION

### Domestic Water Demand

• The total domestic water consumption usually amounts to 50 to 60% of the total water consumption.
• The I.S. Code lays down a limit of water consumption between 135 to 225 litres per capita per day (/pcd).
• Under ordinary conditions (as per I.S. code) the minimum domestic water demand for a town or a city with a full flushing system Should be taken at 200 lpcd. Although it can be reduced to 135 lpcd for economically weaker sections and LIG colonies depending upon prevailing conditions.

1. Minimum domestic water consumption (Annual average) for Indian towns and cities with Full Flushing systems as per 1172-1993.

2. Minimum domestic water consumption (Annual average) for weaker sections and LIG (Lower Income Group) Colonies in small Indian Towns and Cities.

#### WATER TANK CAPACITY CALCULATION

For a Small  LIG (Lower Income Group) family  = 5 Members

Water Consumption in 1 Day  = 135 litre

For 5 member in a Day  = 135 x 5

For 5 members in a Day  = 675 lit.

Assume the water consumption of 1000 lit.

We know water density is 1000 lit/m3

1m3 = 1000 lit.

Water tank volume is  = 1m3

#### WATER TANK SIZE CALCULATION

Water tank volume is  = 1m3

Volume of water tank is DxBxL

Assume water tank depth as your required  = 0.5m

Depth is water tank is,  D= 0.5 m

Area of water tank  = 1/0.5 = 2

Area of water tank,   L x B  = 2 meter squre

Suppose L= 2B

2B X B = 2

B^2   =  2/2

B^2 =1

B = √1

B = 1

Width of water tank is, B= 1 m

Put value of B in assume equation,    Suppose L= 2B

L = 2X1

L = 2

Length of water tank is, L = 2 m

Overall water tank site is DxBxL

0.5x1x2 = 1 meter cube

Here is a plan of the water tank and cross-section of the water tank

Excel Sheet For Size Calculation –

Tutorials tips

### 5 Responses

1. vivek kumar Gupta says:

Hi,
Indeed a very good teaching on Water Tank Calculation. You have made all points cleared here.

I had only one doubt, i.e on your excel sheet when we putting Quantity of Volume its is showing such a 3K + KG of Cement for Tank Size of L= 3 mtr, W= 3 mtr and H= 1.5 mtr
and Bottom Ramp of 3.5 * 3.5 * .02 (L*B*H) (ALL IN METER)

Pls take a look, i would be thankful to you.

2. Jagbhan singh says:

Very good

3. Azmeraw says:

Very important site!!

4. Tauseef says:

how to calculate steel bar in water tank

5. It is required to determine the storage capacity of water supply of the user community. Now, how could we calculate the volume for Maximum daily water per capita demand from R=K*D+[X/24]*[D-P]+F, Where
R=the capacity of Reservoir in litters
D=Average daily demand for general purpose in the month of maximum consumption in litters
F=Reservoir capacity for firefighting in litters/hours
P=pumping rate in litters/hour
X=number of pumping hours
K=Constant for leakage=0.3