Street, Bridge and Culvert Flow Street discharge is simulated as flow in a shallow rectangular channel. Streets may intersect and are delineated with a width and curb height. Bridge and culvert flow on the grid system can be simulated by user specified relationships between the discharge and headwater depth. Levee Simulation and Failure Levees can be simulated by specifying flow directions and crest elevations. Levee failure can occur by overtopping or by inundation at a levee elevation for a specified time period.
Levee failure is simulated on a grid element by grid element basis.
A portion or the entire grid element can be removed from potential inundation. Similarly, the flow transfer between grid elements can be partially or entirely obstructed. Multiple Channel Overland Flow Overland flow can be concentrated in small rills and gullies. When specific grid elements are assigned multiple channels, discharge between those elements occurs as concentrated flow in small, rectangular channels and not as overland sheet flow. Rainfall on the overland portion of each grid element is routed into the element rill or gully.