Product(s):	WaterGEMS, WaterCAD, HAMMER, StormCAD, SewerCAD, SewerGEMS, CivilStorm
Version(s):	All
Area:	Modeling

Problem

How can I create custom fields (attributes), in addition to the default properties and results seen for each element?

Background

Sometimes a need arises to add custom fields (metadata) to your model elements, either input for reference purposes, or new output/results. Examples:

Notes about existing pipes and new pipes in the water network for identification purpose, which you can color code and visualize any time in the water network.
Date when the feature was last inspected
YES or NO Boolean field for certain properties of elements, or pipe condition.

For this purpose, User Data Extensions (UDX) can be created with data type of either text, Boolean, date/time or "real" (number with units). Once created, User Data Extensions work in the properties, Flextables and other places just like other default element attributes. For example you can annotate and color code on User Data Extensions.

Note: when adding UDX fields to a Flextable, consider adding them to a Hydraulic Model Flextable (View > Flextables > "Tables - Hydraulic Model"), since the predefined tables (from the Flextable dropdown menu) will be available in all models, whereas your UDX fields may only be available in one particular model. See more here.

User Data Extension Data Types

The following are the available Data Types that you can use when creating a UDX and typical applications:

Integer —Any positive ornegative whole number.
Text —Any string (text)value up to 255 characters long. Useful for short descriptions/labels.
Long Text —Any string (text) up to 65,526 characters long. Useful for lengthy notes.
Date/Time —A date + time. The current date appears by default in the format month/day/year. Click the down arrow to change the default date.
Boolean —True or False.
Enumerated —When you select this datatype, an Ellipses button appears in the Default Value field. Click the Ellipses(...) button to display the Enumeration Editor dialog box, where you can add enumerated members and their associated values. The enumeration "value" is an ID field used for example when performing operations such as a query. (which needs to refer to this ID, not the actual label) To change or add more options, you can edit an existing enumerated UDX and re-open the Enumeration Editor with the "..." button in the "Default Value" field. For more information, see Enumeration Editor Dialog Box. This can be useful for example if you want to identify conduits in a model of a new subdivision by one of the following states: Existing, Proposed, Abandoned, Removed, and Retired.
Real —Any fractional decimal number (for example, 3.14). It can also be unitized with the provided options (so that it can appear in the same graph axis as other fields with the same unit type). Note: Starting with the 2026 release of the OpenFlows products, the display precision will be allowed out to 15 decimal places, as opposed to 6 for earlier releases.
Real (Formula) —A unitized decimal number whose value is calculated based on a formula. See more here.
Text (Formula) - A text results field whose text value is derived based on a formula (available in version 2026 and higher) See more here.

Creating a User Data Extension

To create your UDX, first close any open Flextables, then go to Tools > User Data Extensions.

Select the desired element type, then click the New button to create the UDX.

Name: internal label
Label: visible label of the UDX (seen in other places like properties and flextables)
Category: the Properties category that the field display in, when viewed in the Property Grid.
- To create a new Category, simply type the desired name in the field next to Category and it will be created when you click OK.
Field order Index: used to adjust the order that the field appears within the selected Category in the Property Grid
Field Description: this is where you can type in a longer description of the field or explanation. This is seen at the bottom of the Property Grid when selecting the attribute.
Alternative: choose which alternative the data is stored in. See: Scenario and Alternative Management
Data Type: the type of field - see list further above
(other fields depend on the selected data type)

Lastly, click OK to create the User Data Extension.

Note: once the UDX is created, the Label and Data Type cannot be changed.

Video Example

As an example, let's take the example of distinguishing new vs. existing network.

You can create a custom "text" type user data extension for pipes and create prototypes for pipes with the default values of pipe diameter, roughness coefficient and text UDX - NEW PIPE etc.

So, you can specify the old water network by creating a selection set of that and specify user defined field as 'OLD PIPES' for example or simply 'E' for existing network and then create prototypes for new pipes to be laid out. So, whenever you will lay out any new pipes it will automatically be categorized under new water pipe network.

Once custom UDX field is created, you can edit that field through pipe properties or pipe flex table to differentiate between new and existing network.

Then, a prototype can be created which will assign this custom field of NEW for new pipes, whenever you lay out any new pipe in the network which will save your time and confusion to differentiate between new and existing pipes.

Also you can then color code the pipe network to distinguish existing and new network visually for reporting purpose as shown below.

A Tip on adding User Data Extensions to Flextables

When adding UDX fields to a Flextable, consider adding them to a Hydraulic Model Flextable (View > Flextables > "Tables - Hydraulic Model"), since the predefined tables (from the Flextable dropdown menu) will be available in all models, whereas your UDX fields may only be available in one particular model. See more here.

How can I create a new Category for my UDX?

If you want your UDX to appear in a new custom-named Category in the Property Grid, simply type the desired category name next to the Category field in the UDX properties:

Once you click OK/Apply, the new category will be created and will appear in alphabetical order in the Properties.

If you want to change the order of the Category, consider adding an underscore prefix.

Can we share Formula-based UDX between element types?

The answer is 'No'. Formula-based UDX cannot be shared, since they will reference properties or results that are only available for a given element. The other types can be shared across elements. As for added value, it can help with duplication of effort, if there is some user-defined property that you want to include for multiple elements. This allows a user to create a UDX once and share it, rather than create the same UDX over and over again. UDX is created for certain element types for eg. a text field for a Pipe can be shared for use in other elements. Please note that I will share filed definition only and not the actual value it holds in the UDX.

Can I share User Data Extensions with other users or models?

UDX are stored inside the model file.

There is the option to export an XML file, and that XML file can be manually imported into another model in order to have the UDX fields available:

You may consider setting up a seed file with all of the Company standards like UDX, symbology, catalogs, Flextables, etc.

How to create custom fields using User Data Extensions