Subcatchment SUDS Controls Grid

This grid contains a series of records defining the SUDS controls structure parameters for the subcatchment, and is displayed by clicking on the button located to the right of the SUDS controls field in the Subcatchment properties.

The fields which comprise the grid are described in the following table.

Database Table Name: hw_sub_suds

Show Columns

Database Names

Size, Type and Units

Defaults and Error Limits

Field Name

Description

Database Field

Data Type

Size

Units

Default

Error Lower Limit

Error Upper Limit

Warning Lower Limit

Warning Upper Limit

SUDS structure ID

 A name which identifies this SUDS structure. id Text            

 

SUDS control ID

The identifier for the SUDS control object, which applies to this structure, can be selected from the dropdown list.

SUDS control objects are defined on the SUDS control tab of the Subcatchment Grid.

Note that a new SUDS control can also be added using the button, located to the left of the subcatchment SUDS controls field, which displays the Insert New SUDS control Object option, allowing you to add the new object.

 suds_structure Text            

 

Control type

 A read-only field which displays the type of SUDS control object. control_type Text            

 

Area

The area of the SUDS structure.

 area Double     0        

Number of units

 The number of SUDS structures of the selected type within this subcatchment. num_units Integer     1      

 

Area of subcatchment

 A read-only field which displays the area of the subcatchment affected by the number of units. This field is automatically updated when the Area or Number of units fields are edited. area_subcatchment_pct Double            

 

Unit surface width

 The width of the outflow face of each SUDS structure. This parameter applies to Green roof, Infiltration trench, Permeable pavement, Rooftop disconnection and Vegetative swale types of that use overland flow to convey surface runoff off from the unit. It is disabled for Bio-retention cell, Rain garden and Rain barrel types of SUDS controls. unit_surface_width Double   L 0      

 

Initial saturation

For Bio-retention cells, Rain gardens, and Green roofs this is the degree to which the unit's soil is initially filled with water (0 % saturation corresponds to the wilting point moisture content, 100 % saturation has the moisture content equal to the porosity). The storage zone beneath the soil zone of the cell is assumed to be completely dry.

For other types of SUDS controls, it corresponds to the degree to which their storage zone is initially filled with water.

 initial_saturation_pct Doube     0      

 

Impervious area treated

 The percent of the impervious portion of the subcatchment's non-SUDS structure's area whose runoff is treated by the SUDS practice. (E.g., if rain barrels are used to capture roof runoff and roofs represent 60% of the impervious area, then the impervious area treated is 60%). If the SUDS unit treats only direct rainfall, such as with a green roof or roof disconnection, then this value should be 0. If the SUDS structure takes up the entire subcatchment then this field is ignored. impervious_area_treated_pct Double     0      

 

Pervious area treated

 The percent of the pervious portion of the subcatchment's non-SUD structure's area whose runoff is treated by the SUD practice. pervious_area_treated_pct Double     0 0 100  

 

Outflow to

 The outflow from the SUDS structure can be set to either Outlet, Pervious or Impervious by selecting the appropriate option from the drop-down list. outflow_to Text     Outlet      

 

Drain to subcatchment

 The subcatchment to which the selected SUDS structure is to drain can be selected from a drop-down list. drain_to_subcatchment Text            

 
Drain to node The node to which the selected SUDS structure is to drain can be selected from a drop-down list. drain_to_node Text            

 
Surface

A surface or a surface type, on which a SUDS control is located, can be selected from a drop down list.

This is required to enable InfoWorks ICM to determine if the subcatchment's runoff surface area needs to be adjusted to account for the SUDS control located in it.

The choices are:

  • All (default)
  • All impervious
  • All pervious
  • Surface 1 - Surface 12

If set to All, the SUDS control will apply to all surfaces within the subcatchment, and will be split between all the surfaces proportionally according to their area. No area adjustment will be applied.

For All impervious and All pervious, the SUDS control will be split between those surfaces proportionally according to their area. Runoff from the other type of surface will be unaffected by the SUDS control.

For each surface (Surface 1 - Surface 12), the SUDS control will be applied to the specified surface only, and the runoff from all other surfaces will be unaffected by the SUDS control. These runoff surfaces are defined in the Runoff Surface Grid Window in the Subcatchments Grid.

Area adjustments are shown in the log file as a list of adjusted areas for the surfaces at each subcatchment. These are the adjusted areas that are passed to the EPA SWMM5 code, which then reduces every surface’s area by the total SUDS area divided by the surface’s area. (It assumes that the SUDS structures are split across all surfaces.) The resulting area for each surface is the surface’s area minus the area of any SUDS controls located on the surface. Simulations that use an existing pre-processor generated file do not show the area adjustments.

 surface Text     All      

 
Note

If both the Drain to Subcatchment and Drain to node fields are blank, then the drain flow goes to the outflow specified in the Outflow to field.

 

Subcatchments Data Fields

SUDS Controls

SUDS Control Types

Property Sheets