Physical Alternative for Catch Basins

The physical alternative editor for catch basins is used to create various data sets for the physical characteristics of catch basins. The following columns are available:

Column	Description
ID	Displays the unique identifier for each element in the alternative.
Label	Displays the label for each element in the alternative.
Inflow Capture Curve	Clicking the Ellipsis (…) button in this field opens the Inflow Capture Curve editor, allowing you to define the inflow capture curve for each element in the alternative that uses the Inflow Capture Curve Inlet Type.
Flow (Maximum in)	Lets you define the maximum inflow for catch basins of the Maximum Inflow Inlet Type.
Inlet Type	Indicates whether the catch basin is Rating Curve or Maximum Inflow type. Clicking a field activates a list box allowing you to switch between the two.
Width	Displays the width of each box catch basin in the alternative.
Length	Displays the length of each box catch basin in the alternative.
Diameter	Displays the diameter of each circular catch basin in the alternative.
Structure Shape Type	Indicates whether the catch basin is circular or box shaped. Clicking a field activates a list box that allows you to switch between the two.
Surface Depth Area Curve	Clicking the Ellipsis (…) button in this field opens the Surface Depth-Area Curve editor, allowing you to define the surface depth area curve for each element in the alternative that uses the Surface Depth-Area Curve Surface Storage Type.
Area (Constant Surface)	Lets you define the area in which ponding occurs at the currently selected element. It is available only when the Surface Storage Type attribute is set to Ponded Area.
Surface Storage Type	Contains a drop-down list box that allow you to specify whether the manhole uses the Default Storage Equation or a Surface Depth-Area Curve.
Elevation (Rim)	—Lets you define the top elevation of a catch basin structure. This elevation is typically flush with the ground surface. In some cases, the rim elevation may be slightly below the ground surface elevation (sunk) or slightly above the ground surface elevation (raised).
Set Rim to Ground Elevation	Enables or disables a data entry shortcut. If the box is checked, the catch basin rim elevation is set equal to the ground elevation automatically.