The runoff curve number (CN) is an non-dimensional empirical parameter
that characterizes the drainage area surface conditions. Landcover types
with higher imperviousness and less infiltration are assigned higher CN values.
Total area of the contributing drainage area (square feet)
Time of concentration (Tc) represents the time it takes for surface runoff
to traverse the entire watershed starting from the most hydraulically
The depth of the storm (inches) falling on this sub drainage area. Adjust this value
if different from the storm depth applied to the rest of the system set in the Point
of Analysis node.
The total depth of the storm (inches) applied to each drainage area. Note: adjusting this overwrites any custom rainfall depth set on sub drainage areas.
Total surface area of the stormwater management practice (square feet)
Depth of the stormwater management practice (feet). This depth must be larger than the height of the overflow weir.
Void space of the storage media in the stormwater management practice. For example, stone storage
typically can be assumed to be 40%.
Diameter of the stormwater management practice outlet orifice (inches)
Elevation of the stormwater management practice outlet orifice (feet)
Elevation of the stormwater management practice overflow weir (feet)
Rate of infitration in the stormwater management practice (inches per hour). This rate is applied
to the basin footprint to determine the rate of water lost to infiltration in the basin.
No data. Please run the model first.
Refer to Figure B-2 of TR-55 for geographic boundaries of NRSC rainfall distributions
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