8. WATER DEMAND
DOMESTIC WATER DEMAND
INDUSTRIAL WATER DEMAND
INSTITUTIONAL & COMMERCIAL WATER
DEMAND
DEMAND FOR PUBLIC USES
FIRE DEMAND
WATER LOSS IN THEFT & WASTE
9. DOMESTIC WATER DEMAND
Water Demand Includes The Water Required
In Private Building For Drinking, Cooking,
Bathing, Gardening Purposes Etc.
Total Domestic Water Consumption Is Near
About 50-60% Of The Total Water
Consumption
As Per IS Code The Minimum Water Required
For LIG IS 135 Lpcd And For Full Flushing
System It Shoud Be Taken As 200 Lpcd
10. INDUSTRIAL WATER DEMAND
The Industrial Water Demand Express The
Water Required For Industries Which Are
Either Existing Or Are Likely To Be Started In
Future.
This Water Requirement Will Vary With The
Type Of Industries Present In City
In Industrial Cities Water Requirement May
Finally Be Computed To Be As High As 450
L/H/D And As Low As 50 L/H/D
11. INSTITUTIONAL &
COMMERCIAL WATER DEMAND
It Is Vary From 20-50 L/H/D For Various Uses In
Institutes Or In Commercial Use.
1. School/College : 46-135 Lpcd
2. Offices : 45 Lpcd
3. Restaurants : 70 Lpcd
4. Cinema/Theatres : 15 Lpcd
5. Hotels : 180 Lpcd
6. Hospitals : 340-450 Lpcd
7. Airports : 70 Lpcd
8. Railway : 70 Lpcd
12. DEMAND FOR PUBLIC USES
This Includes Water Requirement For Parks,
Gardening, Washing Of Roads Etc.
A Nominal Amount, Not Exceeding 5% Of The
Total Consumption May Be Provided To Meet
This Demand
A Figure Of 10 Lpcd Is Usually Added On This
Account While Computing Total Water
Requirements.
13. FIRE DEMAND
To Control Fire Extinguishing This Demand Of
Water Is Required.
The Minimum Water Pressure Available At Fire
Hydrant Should Be Of The Order Of 100-150
Kn/M² (10-15m Of Water Head)
The Jet Streams Are Simultaneously Thrown From
Each Hydrant, The Discharge Of Each Stream
Should Be About 1100 L/Min.
The No. Of Fire Jets Required Depend Upon The
Size Of Population Given By F = 2.8√P
14. WATER LOSS IN THEFT &
WASTE
This Include The Water Lost In Leakage Due
To Bad Plumbing Or Damaged Meters, Stolen
Water Due To Unauthorized Water
Connections & Other Losses & Waste
Even In The Best Managed Water Works, This
Amount May Be As High As 15% Of The Total
Consumption Which Is Nearly 55 Lpcd
These Losses Should Be Taken Into Account
While Estimating The Total Requirements.
15. FLUCTUATIONS IN DEMAND
Maximum Daily Consumption : 180% Of The Avg.
Maximum Hourly Consumption : 150 % Of The
Avg.
Maximum Weekly Demand : 1.48 * Avg. Weekly
Maximum Monthly Demand : 1.28 * Avg.
Monthly
Seasonal Variation
1. In Winter
2. In Summer
3. In Rain
16. POPULATION FORECASTING
Three Factors Responsible For Change In
Population
1. Births
2. Deaths
3. Migrations
The Population Is Calculated In Every 10 Years
In Every Census So If Need Population
Calculation For A Specific Year, Population
Forecast Is Needed
17. METHODS OF POPULATION
FORECASTING
Arithmetic Increase Method
Geometric Increase Method
Incremental Increase Method
Decreasing Growth Rate Method
Graphical Projection Or Extension Method
Comparative Graphical Method
Master Plan Or Zoning Method
Ratio Method
The Logistic Curve Method