Creating the Pond Feature and its Network Connections

The Importance of the Pond Feature Shape

It’s minimal.

We will use an arbitrary shape here rather than a finished 3D pond. Once a Feature, we’ll want to connect the pond to the upstream and downstream networks – so that the software knows where to route the flow.

There is no hydraulic or calculation need for the pond feature’s shape to accurately reflect the pond geometry.  If you have an existing pond or a fixed finished pond, then there may be some value in the shape being “accurate”.  Note that a pond shape coincident with grading features may make seeing the pond and selecting it slightly more difficult.

The Importance of the Pond Feature

The Pond Feature is required as a  data structure to store tables and a Feature to connect to other Features (flow input and output Features).

The pond will need incoming flow from one or more sources (generally, endwalls or outfalls).  It will also need an outlet control structure.  Pond Outlets are a Drainage and Utilities Feature Definition Structure Type with appropriate attributes and Hydraulic Prototypes.

Pond Outlet Structures

Note that workspaces are often set up with  Catch Basins, Endwalls, etc. appearing “straight out of the Standard Drawings” as far as full fine details and perfect geospatial representation.  Pond Outlet Structures are out-of-the-box do not show much 3D detail.  The infinite variations of control structures make representing them accurately very difficult for little benefit.  The hydraulics are never routed though the 3D Structures: it’s all database and math.. 

Generally a rectangular or circular vault with reasonable spatial dimensions is adequate (approximate width, top elevation and bottom elevation).  Top elevations relative to the pond top or berm elevation is useful.  Accurate Inverts of Pipes discharging from the structure are important as flow characteristics are calculated for those pipes.

The Layout > Layout > Place Pond tool

This tool has 1 mandatory outcome:

1.     creating an OpenRoads Pond Feature with a shape attached to it.

It has two structural selection options:

1.     connecting the pond to an upstream discharge

2.     connecting the pond to a “downstream” pond outlet structure.

Finally, like Catchments, you have the option of draping the shape to a surface.  There is little value to this; select <Alt> to leave it as 2D.

The Pick Points method allows you to define the pond shape on-the-fly with your cursor.

You will be prompted to select the structure discharging into the pond and the Pond Outfall Structure controlling its discharge.  You can select the structures or reject (right-click) to define them later.

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Click Layout > Layout > Place Pond

Follow the prompts to create a Pond Feature. Use the shape in the file or use Pick Points to create your own. If you're feeling bold, try the From Terrain Model method.  Not and connect to the inflow and outflow structures (either in the command or via the Utilities Properties dialog).

A mandatory follow up is to provide some stage/storage (Elevation-Area or Elevation-Volume) information.

1. In the Pond feature's Utility Properties, select the Volume Type field, and select Elevation-Area.

This will show the Elevation Area field, which starts with an empty table (a Collection of 0 items),

1. click the  icon:

Connect the Pond Outlet Control Structure to the Pond

1. Select the Pond Outfall Structure and in the Utilities Properties dialog Pond Outlet settings group, click on the Upstream Pond field:
2. 
3. Click <Select Upstream Pond>
4. Select the Pond Feature in the drawing.