Headwall Connectivity and Function in Model

The Headwall element is a jack-of-all-trades and can act as the following:

Culvert entrance/exit
Network outfall
Pond Entrance
Pond Outlet
Open channel cross section to closed channel transition

Headwalls and Conduits

When a headwall is connected to a conduit it represents the transition from an open channel to a closed channel or vice versa. You can use the headwalls to define inlet/exit structures for a culvert as well.

To do so:

On the headwall set the "Inlet Description" to the appropriate set Culvert Inlet Coefficients.
On the connecting Conduit set the "Is Culvert?" flag to true.
Then specify whether or not to set the culvert inlet coefficient set for upstream and downstream inlets either based on the adjacent headwall or to simply specify on the conduit itself.

Headwalls and Channels

When a channel link connects to a headwall you can specify the shape of the cross section at the interface of the open channel and the headwall structure.

To do so:

Set "Has Cross Section?" to true.
Specify the shape parameters of the cross section.

Headwalls and Ponds

A headwall can represent inflow or outflow structure of a pond.

To make a headwall an inflow structure:

Set the "Boundary Condition Type" to "Boundary Element".
In the "Boundary Element" field pick "<Select Boundary Element>" option.
In the drawing pick the pond that receives the inflow from the headwall.

To make a headwall an outlet structure for a pond:

In the "Upstream Pond" field pick the "<Select Upstream Pond>" option.
Then select the pond that outflows to headwall.