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Stormwater Volume Formula:
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The stormwater calculation formula estimates the volume of stormwater runoff from a given area. It is commonly used in civil engineering, urban planning, and environmental management to design drainage systems and manage water resources.
The calculator uses the stormwater volume formula:
Where:
Explanation: The formula calculates the volume of water that runs off from a surface during a rainfall event, accounting for the area size, rainfall intensity, and surface characteristics through the runoff coefficient.
Details: Accurate stormwater volume estimation is crucial for designing effective drainage systems, preventing flooding, managing water quality, and meeting regulatory requirements for stormwater management.
Tips: Enter area in hectares, rainfall in millimeters, and appropriate runoff coefficient. All values must be valid positive numbers (area > 0, rainfall > 0, coefficient between 0-1).
Q1: What is a runoff coefficient?
A: The runoff coefficient represents the fraction of rainfall that becomes surface runoff. It varies based on surface type (e.g., 0.9 for paved areas, 0.3 for lawns).
Q2: Why divide by 360 in the formula?
A: The division by 360 is a conversion factor that accounts for the units used (ha to m², mm to m) to give the result in cubic meters.
Q3: How accurate is this calculation?
A: The formula provides a reasonable estimate but actual runoff can be affected by factors like soil saturation, slope, and rainfall intensity.
Q4: When is this formula typically used?
A: This formula is commonly used for preliminary designs, small catchment areas, and educational purposes. More complex models may be needed for large or complex watersheds.
Q5: Can this be used for commercial projects?
A: While useful for estimates, professional engineering designs typically require more sophisticated modeling that considers additional factors like time of concentration and rainfall distribution.