Storm Drain

The entire storm drain model is developed from the storm drain and optional drainage coverages. The storm drain coverage is used to define the pipe network system and the attributes associated with each node. The storm drain coverage can be connected to a surface drainage coverage in order to pass the computed hydrograph (or the use the defined rational method parameters) to the linked nodes.

Storm Drain Line Types

All lines (arcs) in the storm drain coverage are considered to be pipes, and the attributes of the pipes can be defined for each individual pipe segment. When not specifically defined the pipe attributes are inherited from the global definition for pipes defined in the storm drain Job Control dialog. The attributes for pipes include:

A pipe type can be specified from a drop-down list showing typical pipe materials. When the type is selected a default Manning's n typical for that material is updated automatically. The color of the line will also change to reflect the pipe type.

Storm Drain Node Types

The nodes in storm drain coverages can be manholes, pipe junctions, outfalls, or reservoirs and they control the hydraulic computations as a storm drain network computation is performed. The default type is junction. The only required parameter for a junction type node is the angle. A manhole node requires the angle, but in addition requires input for the width and the bench type. There should only be one outfall node and along with the outfall node a tailwater elevation should be entered for computation of the hydraulic grade line within the pipe network. Finally a node can be specified as a reservoir node. A reservoir node can be used to route water from the pipe network through a detention basin facility. A simple volumetric reservoir can be defined, or a complete storage routing performed with stage/storage and stage/discharge rating curves defined.

Related Topics:
Storm Drain Modeling
Drainage Coverage