Water Demand Calculator

Calculate water demand for cities, communities, and regions. Estimate average daily, maximum daily, and peak hour water demand for municipal planning and infrastructure design.

Water Demand Parameters

Total number of people in the area/city

WHO/UN recommended standard

% additional for waste/losses

Advanced Parameters

Default: 1.4

Default: 2.3

Water Demand Formula

ADD = LPCD × P + Waste%
Average Daily Demand = Liters per Capita per Day × Population + Waste
Population (P):100.00 thousand
LPCD:225 L/capita/day
Waste/Losses:10%

Water Demand Results

Average Daily Demand

24.75 million L/day

Maximum Daily Demand

34.65 million L/day

Peak Hour Demand

658.9 L/s

Annual Demand

9.03 billion L/year

Per Capita Analysis

Base Usage per Person:225 L/day (59 gal/day)
With Waste/Losses:248 L/day
Annual per Person:82.13 thousand L/year

Waste Allowance: 2.25 million L/day accounts for distribution losses, leaks, and system inefficiencies.

Infrastructure Sizing

Storage Tank Capacity:69.30 million L
Pump Capacity (Peak):2371875 L/hour
Treatment Plant Size:34.65 million L/day

Recommendations: Tank capacity = 2× max daily demand, treatment = max daily demand

Typical Water Usage Breakdown

Residential (60%)

  • • Toilet flushing (24%)
  • • Showers/bathing (17%)
  • • Laundry (16%)
  • • Faucets (19%)
  • • Leaks (12%)
  • • Other (12%)

Commercial (25%)

  • • Office buildings
  • • Restaurants
  • • Hotels
  • • Retail stores
  • • Public facilities

Industrial (15%)

  • • Manufacturing
  • • Cooling systems
  • • Process water
  • • Food processing
  • • Energy production

Global Water Usage Comparison

High Usage Regions

United States:500 L/capita/day
Australia:340 L/capita/day
Italy:250 L/capita/day
Spain:230 L/capita/day

Efficient Regions

Denmark:120 L/capita/day
Netherlands:130 L/capita/day
Germany:140 L/capita/day
Estonia:110 L/capita/day
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