Channel Capacity Calculator

Fetching design rainfall…

Calculation Name

I know my rainfall intensity

Enter a value you already have (in/hr).

Calculate from ZIP (pick my own duration + ARI)

We’ll look up the PFDS table using your ZIP, but you choose duration & frequency.

Calculate from ZIP (suggested by site type)

We’ll use site type to suggest duration & frequency; you can still edit later.

Enter the square footage for each surface type. You can also tweak the rainfall intensity if needed.

Rainfall Intensity (in/hr)

Asphalt/Concrete (sq. ft) Brick (sq. ft)

Roofs (sq. ft) Lawns - Sandy Soil (sq. ft)

Lawns - Heavy Soil (sq. ft)

We’ll use these to compute velocities and match channels.

Article Number

Required Material Required Load Class

Line Length (ft) Longitudinal Slope Number of Outlets

“Note: *The hydraulic calculation is calculated based on the last trench drain in the system, taking into account the slope and full line capacity.

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