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Routing Ponds
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7 Click Save to save the file.
The file is saved with an .scc file extension in the c:\Land Projects R2\<project
name>\hd folder, and you are returned to the Stage-Storage Display dialog box.
8 You can also output the data to a text or .wk1 file, change the graph settings,
and plot the graph by using the following guidelines:
If you want to} Then click}
output the data to a text or .wk1 file Output.
change the graph settings Settings.
plot the graph Plot.
9 Click Close to close the Stage-Storage Curve Display dialog box.
Routing Ponds
One of the most common requirements for post-development stormwater
management is that the post-development discharges do not exceed the pre-
development discharges for one or more storm frequencies. The detention basin
is generally the least expensive and most reliable measure for controlling post
development peak discharges.
When the runoff enters a detention pond, the flow is attenuated, meaning that
the peak rate of inflow is "detained. The water flowing out of the pond,
therefore, exits at a slower rate. This attenuation of flow is a main goal of
stormwater management.
To begin the process of designing a detention pond, you start by calculating the
post-development runoff using one of the runoff calculation methods. The
hydrograph of the post-development runoff flow is referred to as the inflow
hydrograph because it represents the peak flow of water entering the detention
pond.
Using this inflow hydrograph (and other runoff data), you can calculate the
required storage volume for a pond. In addition, you can generate the outflow
hydrograph that represents the rate of discharge of the water flowing out of the
detention pond.
This process of calculating the outflow hydrograph for a detention basin based
on the inflow is called routing.
Autodesk Civil Design provides two commands you can use to calculate routing
data. You can use the Detention Basin Storage command to calculate the
required storage volume for a pond, and you can use the Storage Indication
Method command to calculate a routed hydrograph.