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Table Of Contents
Calculating Riser Values
531
The following illustration shows the riser values required for designing a riser:
Riser values
To calculate riser values
1
From the Hydrology menu, choose Riser Calculator to display the Riser
Calculator dialog box.
TIP
You can click Load to load an existing riser file, or click New to clear the
calculator of its current values.
NOTE
When you input all of the riser data, the Riser Calculator determines the
optimum riser and pipe diameters based on the defined riser and pipe
diameters that are in tables called rsrdiam.dia and rsrpipe.dia. If you want
to exclude a certain diameter from being used by the calculator, or add a
new diameter, then click the Tables button. For more information, see
"Customizing Riser Diameter and Pipe Diameter Tables" in this chapter.
2
In the Base Flow box, type a base flow value.
3
In the Riser Elev box, type a riser elevation. For more information about this
value and other values in the Riser Calculator, see the preceding illustration on
riser values in the introduction of this topic. You can also click Select, and select
a point in the drawing to specify a riser elevation. For more information, see
Selecting Riser Points from a Drawing in this chapter.
4
In the Invert In box, type an invert in elevation. You can also click Select, and
select a point in the drawing to specify an invert in elevation. For more
information, see Selecting Riser Points from a Drawing in this chapter.
5
In the Invert Out box, type an invert out elevation. You can also click Select,
and select a point in the drawing to specify an invert out elevation.
6
In the Surface Elev box, type a surface elevation. This is the water surface
elevation. You can also click Select, and select a point in the drawing to specify
a surface elevation.
7
In the Spillway Crest box, type a spillway crest elevation. You can also click
Select and select a point in the drawing to specify a spillway crest elevation.
8
In the Pipe Length box, type a pipe length. You can also click Select and select
two points in the drawing to specify a pipe length.
9
In the Mannings n box, type a Mannings n coefficient for the pipe. You can
also click Select to open the Pipe-Mannings n dialog box. Select a Mannings n
value by placing your cursor in the appropriate column, and clicking OK.