1. What is Rainwater Volume Calculation?

Rainwater volume calculation estimates the amount of rainwater that can be collected from a specific surface area. It's essential for designing rainwater harvesting systems, drainage systems, and water management planning.

2. How Does the Calculator Work?

The calculator uses the rainwater volume formula:

Where:

• \( RV \) — Rainwater Volume (m³)
• \( A \) — Collection Area (m²)
• \( R \) — Rainfall Depth (mm)
• \( C \) — Runoff Coefficient (0-1)

Explanation: The formula calculates the volume of rainwater by multiplying the collection area by rainfall depth (converted to meters) and the runoff coefficient that accounts for losses.

3. Importance of Rainwater Harvesting

Details: Accurate rainwater volume calculation is crucial for sustainable water management, reducing municipal water consumption, flood control, and designing efficient rainwater collection systems.

4. Using the Calculator

Tips: Enter area in square meters, rainfall in millimeters, and runoff coefficient between 0-1. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the runoff coefficient?
A: The runoff coefficient represents the percentage of rainfall that becomes available runoff. It ranges from 0 (no runoff) to 1 (all rainfall becomes runoff).

Q2: How do I determine the runoff coefficient?
A: Runoff coefficient depends on surface material: concrete (0.8-0.9), asphalt (0.8-0.9), grass (0.1-0.3), gravel (0.3-0.6).

Q3: Why convert rainfall from mm to meters?
A: Since 1 mm rainfall = 1 liter per m², and 1000 liters = 1 m³, we divide rainfall by 1000 to get meters for volume calculation.

Q4: What's a typical collection area?
A: Roof areas are commonly used for rainwater harvesting. Measure length × width of the roof projection.

Q5: How accurate is this calculation?
A: The calculation provides a theoretical maximum. Actual collection may be less due to evaporation, spillage, and first-flush diversion.