Weir Curve Data Fields (SWMM)

A weir curve in a SWMM network is used to define the relationship between the head difference and the discharge coefficient for the weir.

Information relating to a weir curve can be viewed and edited on the Weir Curve Grid Window of the Links Grids or on the Weir Curve Property Sheet.

Most data can be edited on the grid, but some fields cannot be displayed in the grid format.

To view and edit all weir curve data, use the Property Sheet.

The table below describes all the data which can be used to define a weir curve. For details of results fields for links, see the Link Results Data Fields (SWMM) topic.

Common Data Fields

Fields that are common to the majority of objects can be found in the Common Fields topic.

Weir Curve Data

Database Table Name: sw_curve_weir

Field Name

Help Text

Database Field

Data Type

Size

Units

Precision

Default

Error Lower Limit

Error Upper Limit

Warning Lower Limit

Warning Upper Limit

Weir curve ID

The unique name for the weir curve, up to 254 letters, numbers and underscore characters. Upper and lower case letters are treated as being the same.

This name cannot be used by any other curve in the SWMM network.

Text

254

Weir curve type

The type of weir that this curve applies to. The following options are available:

Weir - for Transverse, Roadway, V-notch, or Trapezoidal types of weirs
Sideflow - for sideflow types of weirs

Weir array

Displayed when Weir curve type is set to Weir

This field contains a series of records defining the data for a Weir type of weir curve. These are entered on the Curve Editor which is displayed by clicking on the button.

Database Table Name: sw_curve_weir_data

Show Columns	Database Names
	Size, Type and Units
	Defaults and Error Limits

Field Name	Help Text	Database Field	Data Type	Size	Units	Precision	Default	Error Lower Limit	Error Upper Limit	Warning Lower Limit	Warning Upper Limit
Head difference	The head difference across the weir.	head	Double		Y	3
Discharge coefficient	The corresponding coefficient for flow through the central part of the weir.	coefficient	Double		SW_WEIRCOEF	3

data

Structure

Sideflow array

Displayed only when Weir curve type is set to Sideflow.

This field contains a series of records defining the data for a Sideflow type of weir curve. These are entered on the Curves Editor which is displayed by clicking on the button.

Database Table Name: sw_curve_roadway_data

Show Columns	Database Names
	Size, Type and Units
	Defaults and Error Limits

Field Name	Help Text	Database Field	Data Type	Size	Units	Precision	Default	Error Lower Limit	Error Upper Limit	Warning Lower Limit	Warning Upper Limit
Head difference	The head difference across the sideflow weir.	head	Double		Y	3
Discharge coefficient	The corresponding coefficient for flow over sideflow weirs.	coefficient	Double		SW_SWEIRCOEF	3

data

Structure

Curves (SWMM)

Curve Editor (SWMM)

Weir Data Fields (SWMM)

Property Sheets

Links Grids