1. What is Rain Catchment Calculation?

Rain catchment calculation estimates the amount of rainwater that can be collected from a specific surface area. It helps in designing rainwater harvesting systems and water conservation planning.

2. How Does the Calculator Work?

The calculator uses the rain catchment equation:

Where:

• \( RC \) — Rain catchment (gallons)
• \( A \) — Collection area (square feet)
• \( R \) — Rainfall (inches)
• \( 0.623 \) — Conversion factor (gallons per square foot per inch of rain)

Explanation: The equation calculates the volume of rainwater that can be collected from a given surface area during a specific rainfall event.

3. Importance of Rain Catchment Calculation

Details: Accurate rain catchment estimation is crucial for designing efficient rainwater harvesting systems, water conservation planning, and sustainable water management practices.

4. Using the Calculator

Tips: Enter collection area in square feet and rainfall in inches. All values must be valid (area > 0, rainfall > 0).

5. Frequently Asked Questions (FAQ)

Q1: Why is the conversion factor 0.623?
A: 0.623 represents the number of gallons collected per square foot per inch of rainfall (1 sq ft × 1 inch = 0.623 gallons).

Q2: What is a typical collection efficiency?
A: Most systems achieve 80-90% efficiency due to evaporation, splash loss, and first flush diversion.

Q3: How does roof material affect collection?
A: Smooth, impervious surfaces (metal, tile) have higher efficiency than porous surfaces (thatched, gravel).

Q4: Can this be used for large-scale planning?
A: Yes, the same calculation applies for large areas by scaling up the inputs accordingly.

Q5: How accurate is this calculation?
A: It provides a theoretical maximum. Actual collection may be 10-20% less due to system inefficiencies and losses.