Technical data

Grading the Surface for a Detention Pond

You can use the detention pond design features of Autodesk Civil

Design to design retention and/or detention ponds for controlling

peak flow rate amounts from watersheds.

Before you begin the grading plan for the detention pond, determine

the design criteria for the pond, such as the volume of water that the

pond has to store. To do this you can use the Autodesk Civil Design

Hydrology commands. You can use the Graphical Peak Discharge,

Rational, or Tabular Hydrograph Methods, or you can determine this

information from inflow hydrograph and outflow hydrographs. For

more information about calculating pond storage volume, see

Chapter 3, ”Performing Hydrologic Studies.”

Key Concepts

■

You can define pond perimeters from polylines or contours.

■

You can import existing pre-defined pond shapes into the drawing.

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You can shape a pond by applying a template to the pond, by

defining single or multiple slopes for the pond, or by defining what

the final pond volume should be.

■

A pond template is a cross-sectional view of the pond perimeter.

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You can use daylighting to match the pond side slopes into the

existing ground surface model.

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Refer to the SCS (Soil Conservation Service) TR-55 manual for more

information regarding detention pond design.

To design a detention pond

Steps

Use

to look up

1 Determine the specific watershed characteristics

and design criteria, including the peak flow rate

volume to store.

2 Draw the pond perimeter polyline.

Draw a Pond Perimeter

3 From the Grading menu, choose Define

Pond

➤

By Polyline to define the pond

perimeter polyline.

Define a Pond Perimeter

from a Polyline