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Table Of Contents
Chapter 5 Working with Hydrology Commands
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To specify the tailwater depth
1 In the Culvert Design dialog box, click the Select button next to the Tailwater
box to display the Tailwater Editor dialog box.
2 Do one of the following to specify the tailwater:
n
Select Tailwater Only to specify a fixed number for the depth of flow at the
tailwater, then enter the depth in the box. Note that this number is a relative
depth above the outlet invert and elevation is not considered.
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Select Downstream Channel to specify the tailwater depth by solving for the
Depth of Flow in the Advanced Channel Calculator dialog box. Click Select
to open the calculator. Here you enter data to approximate the shape of the
channel at the culvert outlet. The culvert calculator then uses the flowrate
and the channel properties to determine the depth of flow at the outlet. For
more information, see Calculating Channel Values With User-Defined Left
and Right Radii and Slopes in this chapter.
n
Select Tailwater Curve to base the tailwater depth on data from a rating curve
file that you specify. When you calculate channel values using a channel
calculator, you can save the results to a rating curve file. This is a data file
that contains depths versus flowrates. This data file can be created using any
of the channel calculators. After a Tailwater curve is specified, the culvert
calculator uses the flowrate specified and the Tailwater curve to determine
the depth at the outlet.Type the path to the data file in the edit box, or click
Select to select the file from a standard file load dialog box.
3 Click OK to return to the Culvert Design dialog box.
Specifying the Culvert Length
You can specify a culvert length from the Culvert Design dialog box by
selecting a beginning and ending point from your drawing.
To specify a culvert length
1 In the Culvert Design dialog box, click the Select button next to the Length
box. The Culvert Design dialog box closes temporarily and the following
prompt is displayed:
Culvert length – First point (or Entity):
2 Select the first point from the drawing.
The following prompt is displayed:
Length – Second point: