1. What is the Water Demand Equation?

The water demand equation calculates the average daily water requirement for a population based on per capita consumption and population size, including a 10% additional factor for losses and variations.

2. How Does the Calculator Work?

The calculator uses the water demand equation:

Where:

• \( ADD \) — Average daily demand (liters/day)
• \( LPCD \) — Liters per capita per day (liters/person/day)
• \( P \) — Population size
• \( 10\% \) — Additional factor for losses and variations

Explanation: The equation accounts for basic water needs plus additional requirements for system losses, commercial uses, and other non-residential demands.

3. Importance of Water Demand Calculation

Details: Accurate water demand estimation is crucial for designing water supply systems, sizing infrastructure components, and ensuring adequate water supply for communities.

4. Using the Calculator

Tips: Enter LPCD value (typically 150-300 liters/person/day in urban areas), population size, and click calculate. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical LPCD value?
A: Urban areas typically use 150-300 LPCD, while rural areas may use 50-100 LPCD depending on water availability and living standards.

Q2: Why include the 10% additional factor?
A: This accounts for system losses, commercial uses, public facilities, and other non-residential water demands not covered by per capita residential use.

Q3: How does water demand vary throughout the day?
A: Daily peak factors of 1.5-2.0 are often applied to the average daily demand to account for hourly variations.

Q4: What affects LPCD values?
A: Climate, living standards, water availability, cost, and conservation measures all influence actual per capita consumption.

Q5: How should this be used for system design?
A: The calculated ADD should be multiplied by appropriate peak factors to determine maximum daily and hourly demands for infrastructure sizing.