Weir Data Fields (InfoWorks)

Weirs are used for overflow structures and for outlets to storage ponds. Weir controls have the same characteristics for both flow directions. Weir data can be edited on either the Weir Grid Window of the Links Grid or the Weir Property Sheet.

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

This table describes all the weir specific data which can be used to define a weir. For details of results fields, see the Link Results Data Fields topic.

Common Data Fields

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

Weir Data

Database Table Name: hw_weir

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

US Node ID

Type in a node reference or choose an existing node reference from the drop down list. This makes up the first part of the link reference.

us_node_id

Text

DS Node ID

Type in a node reference, or choose an existing node reference from the drop down list.

ds_node_id

Text

Link suffix

A single character between A and Z or 0 and 9 which completes the link reference. This allows a node to have up to 36 downstream links. The suffix is automatically allocated by the software.

link_suffix

Text

Link type

The sub-type for this weir. Select from the dropdown list.

Database Value	Description
WEIR	Weir
VCWEIR	Variable crest level weir	Only applicable for RTC Simulations
VWWEIR	Variable width weir	Only applicable for RTC Simulations
COWEIR	Contracted weir
VNWEIR	V-Notch weir
TRWEIR	Trapezoidal (Cipolletti) weir
BRWEIR	Round nosed broad-crested weir
GTWIER	Gated weir	Only applicable for RTC Simulations

link_type

Text

WEIR

System type

Choose the System Type from the dropdown list. See System Type for more information.

Database Value	Description	Help Text
STORM	Storm	Rainfall collection system
FOUL	Foul	Wastewater collection system (UK terminology)
SANITARY	Sanitary	Wastewater collection system (US terminology)
COMBINED	Combined	Rainfall and wastewater collection system
OVERLAND	Overland	Overland floodwater collection system
OTHER	Other	Other system type

system_type

Text

Other

Asset ID

For reference only. Designed as a reference to an asset database, but could be used for anything.

asset_id

Text

Sewer reference

An optional reference to identify the sewer of which this conduit is a part.

sewer_reference

Text

Branch ID

Numeric field used to identify to which long section the link is associated.

Can be set manually or automatically (see Defining Branches topic for more information).

branch_id

Long Integer

InfoAsset unique ID

Unique ID associated with the corresponding object in an InfoAsset Manager database. When importing from InfoAsset Manager, the InfoAsset ID can be copied from the InfoAsset database in order to maintain links between the two networks.

asset_uid

GUID

InfoAsset ID

Used to store the ID of the corresponding InfoAsset object when Importing from a Collection Network.

infonet_id

Text

DS settlement efficiency (%)

See Upstream Settlement Efficiency.

ds_settlement_eff

Long Integer

100

US settlement efficiency (%)

The Settlement Efficiency fields allow you to set the effectiveness of an overflow for trapping out sediment. The overflow is a link (normally a pipe) attached to a node acting as a storage tank (storage node or manhole).

Normally the upstream end of the link will be attached to the node and act as the overflow. The Upstream Settlement Efficiency determines the efficiency for the overflow.

In some circumstances the link may be reversed (storage tank at the downstream end) and the Downstream Settlement Efficiency will be used.

In many cases an overflow will attach to an outfall from the system.

It would be very unusual to have both Upstream Settlement Efficiency and Downstream Settlement Efficiency set to non-zero values.

The valid range is 0-100%. 0% means the overflow acts as a normal continuation link. 100% means that the overflow traps out as much sediment as possible.

us_settlement_eff

Long Integer

100

Crest

The level at which the weir first comes into operation. For vee and trapezoidal notch weirs, and contracted rectangular weirs, this is the height of the base of the notch. For a gated weir this is the height of the sill.

InfoWorks ICM uses this as the initial value for a Variable Crest Weir or a gated weir unless overridden by the data entered on the Regulator Page.

crest

Double

-9999

9999

6000

Width

The width of the rectangular weir. InfoWorks ICM uses this value as the initial value for a Gated Weir or a Variable Width Weir unless overridden by the data entered on the Regulator Page.

width

Double

Roof height

Roof Height for the weir (optional, more for pipes than open channel). If you enter a value here, the weir behaves as a sluice gate when the water level is above the roof height. If you do not give a value here, it is assumed that the weir does not have a roof.

Applies only to WEIR, VCWEIR, and VWWEIR types of weir.

height

Double

Length

The distance across the flat part of the top of the weir measured parallel to the direction of flow. The distance does not include the round noses of the weir

Broad Crested Weir only.

length

Double

Discharge coefficient

The coefficient for the weir flow equations.

A default value of 0.85 corresponds to a weir of width equal to that of the approach channel for the Standard Rectangular Weir types WEIR, VCWEIR and VWWEIR only. Values typically range between 0.2 and 3.0.

For gated weirs (GTWEIR), a default of 1 is used.

discharge_coeff

Double

0.01

Secondary discharge coefficient

This applies when the depth of water is greater than the roof or gate height, and orifice/sluice gate equations apply.

The default is either the primary discharge coefficient (for Standard Rectangular Weir types WEIR, VCWEIR or VWWEIR) or 1 for gated weirs (GTWEIR).

secondary_discharge_coeff

Double

0.01

Reverse discharge coefficient

Discharge coefficient for reverse gate for a gated weir (GTWEIR).

The default is 1.

reverse_gate_discharge_coeff

Double

0.01

Notch height

The vertical distance from the base (apex) of the notch to the top of the weir plate.

Vee and Trapezoidal Notch Weirs only.

notch_height

Double

0.06

Notch angle

The angle at the base (apex) of the notch in degrees. This means the full angle, not the angle of side slope.

Vee Notch Weir only.

Note: This angle is calculated automatically when importing data from SWMM5.

notch_angle

Double

ANGLE

100

Notch width

For Contracted Rectangular Weirs, this is the width of the single notch.

For Trapezoidal Notch Weirs this is the width of the base of one notch. The weir may have more than one notch. The side slope of all notches is assumed to be 14 degrees.

Contracted Rectangular and Trapezoidal Notch Weirs only.

notch_width

Double

0.000001

Number Of notches

You can have more than one vee or trapezoidal shaped notch in a weir. Enter the number here. All the notches are identical.

Vee and Trapezoidal Notch Weirs only.

number_of_notches

Long Integer

Modular limit

Modular limit for a gated weir.

modular_limit

Double

0.7

0.01

Gate height

The height of gate (dimension from bottom to top of gate).

gate_height

Double

Orientation

The direction of the gate can be set to Forward or Reverse.

orientation

Text

FORWARD

Minimum opening

The minimum opening height for a gated weir. This value must not exceed the specified Gate height.

minimum_opening

Double

Maximum opening

The maximum opening height for a gated weir.

maximum_opening

Double

Initial opening

The initial opening height for the gated weir.

initial_opening

Double

Minimum width

The minimum width for a variable weir.

Applies to a variable width weir (VWWEIR) or, if the Minimum crest field is not set, then this parameter will also apply to variable crest level weir (VCWEIR).

minimum_width

Double

Maximum width

The maximum width for a variable weir.

Applies to a variable width weir (VWWEIR) or, if the Maximum crest field is not set, then this parameter will also apply to variable crest level weir (VCWEIR).

maximum_width

Double

999

Minimum crest

The minimum elevation for a variable crest level weir.

If not set, the specified Minimum width will be used instead.

minimum_elevation

Double

Maximum crest

The maximum elevation for a variable crest level weir.

If not set, the specified Maximum width will be used instead.

maximum_elevation

Double

999

Positive change

The rate at which the width increases or the crest rises. The value must be greater than zero.

positive_speed

Double

0.000001

Negative change

The rate at which the width decreases or the crest falls. The value must be greater than zero.

negative_speed

Double

0.000001

Threshold

The minimum change in width (VWWEIR) or crest level (VCWEIR and GTWEIR) that the software will implement. Any smaller change will be ignored. This prevents oscillation.

threshold

Double

Points

This field defines the geometry of the link. The underlying data consists of a series of (x,y) pairs defining the vertices of the link. Each link is made up of a series of straight lines between the defined (x,y) points.

This data is not displayed on the grid or property sheet.

Link Vertice Export

Link vertices are included when you export link data to CSV files. There are two options available for exporting link vertices. These are selected on the Select CSV Export Options Dialog using the Coordinate Arrays Format dropdown list. The options are:

Packed - The data is exported as a series of x,y pairs.

Separately - the data is appended to the end of the row containing the link data. Each x and y value is in a separate (comma separated) field.

point_array

Array

Weir Controls

Links Grid

Property Sheets