Understanding Catchment Area
The catchment area calculator helps you determine the surface area needed to collect a specific amount of rainwater. This is essential for designing rainwater harvesting systems for irrigation, water conservation, or sustainable building projects.
The Catchment Area Formula
The formula for calculating catchment area is:
[
\text{Catchment Area} = \frac{\text{Harvested Water}}{\text{Rainfall Depth} \times 0.623}
]
Where:
- Harvested Water is measured in gallons
- Rainfall Depth is measured in inches
- 0.623 is the conversion factor for ft²
Example Calculation
Let's calculate the catchment area needed to harvest 50 gallons from 4 inches of rainfall:
- Harvested Water: 50 gallons
- Rainfall Depth: 4 inches
- Calculate: 50 / (4 × 0.623) = 50 / 2.492 = 20.09 ft²
Common Catchment Areas
Here are typical catchment areas for different scenarios:
| Harvested Water | Rainfall | Catchment Area |
|---|---|---|
| 100 gallons | 2 inches | 80.26 ft² |
| 50 gallons | 4 inches | 20.09 ft² |
| 200 gallons | 3 inches | 107.01 ft² |
| 150 gallons | 5 inches | 48.15 ft² |
Practical Applications
- Residential rainwater harvesting: Design roof collection systems for home water supply
- Irrigation planning: Determine catchment needs for garden and landscape watering
- Sustainable construction: Size rainwater collection systems for green building projects
- Water conservation: Calculate potential water savings from existing roof areas