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Runoff Volume Formula:
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Runoff volume calculation estimates the amount of water that flows over a surface during rainfall events. It's essential for drainage design, flood control, and stormwater management in civil engineering and environmental planning.
The calculator uses the runoff volume formula:
Where:
Explanation: The formula multiplies rainfall depth by surface area to get total water volume, then applies the runoff coefficient to account for absorption and infiltration losses.
Details: Accurate runoff volume calculation is crucial for designing effective drainage systems, preventing flooding, managing stormwater, and meeting environmental regulations for construction projects.
Tips: Enter rainfall in inches, area in square feet, and runoff coefficient as a decimal between 0-1. All values must be valid positive numbers.
Q1: What are typical runoff coefficient values?
A: Runoff coefficients range from 0.05-0.35 for pervious surfaces like lawns, 0.75-0.95 for impervious surfaces like pavement, and 0.85-0.98 for roofs.
Q2: How is rainfall data obtained?
A: Rainfall data can come from local weather stations, historical records, or design storm specifications for specific return periods.
Q3: What units are used in the calculation?
A: This calculator uses inches for rainfall and square feet for area, resulting in cubic feet volume. Convert to gallons by multiplying by 7.48052.
Q4: When is this calculation most important?
A: This calculation is critical for drainage design, stormwater management systems, flood risk assessment, and environmental impact studies.
Q5: Are there limitations to this simple formula?
A: Yes, this simplified approach doesn't account for rainfall intensity, duration, soil saturation, or complex topography. More sophisticated models may be needed for precise engineering designs.