What's New in HAMMER 2026 (version 26.00.00.508)


Products: HAMMER
Version(s) 26.00.00.508
Area: Installation
Released on: 2026-May-7

Overview

A new version of OpenFlows Water 2026, which consists of WaterGEMS, WaterCAD, and HAMMER, has been released. This article provides an overview of the new features and updates in this release, specifically for HAMMER.

For information on What's new in WaterCAD and WaterGEMS 2026, see: What's New in OpenFlows Water 2026 (version 26.00.00.508)

Table of Contents

 

Expanded Coordinate System support

With this release, you can now specify the coordinate system of external data and the software will automatically reproject as needed, to align with the model's coordinate system:

This enables you to seamlessly align external data with your hydraulic model without the need for GIS integration. Additionally, you can now easily fix a model's coordinate system without relying on external workflows to reproject, by changing the model's coordinate system in the Options dialog and choosing the option to reproject.

Lastly, the coordinate system selection dialog now displays a map when selecting a coordinate system, highlighting the covered area. This helps you verify that the coordinate system is correct:

 

More information on using coordinate system in the standalone version of the OpenFlows products can be found at the following link: Working with coordinate systems in the OpenFlows standalone platform.

Air valve Enhancements

This release introduces several enhancements for air valves in HAMMER:

Ability to treat an air valve as a junction in a transient simulation

This new air valve property enables you to specify whether or not to treat the air valve as a junction (as if it is not there) during a transient simulation,  so no air inflow or outflow is modeled. Not to be confused with the steady state/EPS-focused "Treat as Junction (Steady State/EPS".

This option is helpful when you want to set up another scenario where the air valve is not present, such as "no protection" scenarios. You no longer need to use active topology to accomplish that.

To use this new option, open the Properties grid for the air valve and set “Treat as Junction? (Transient)” to True:

Information on this has been included in the following article: Modeling Reference – Air Valves

New Air Valve Air Flow calculation Method

The Wylie-Streeter method of calculating the air flow for air valves has been added to HAMMER.

Prior to version 2026, HAMMER always used the Comolet method described, which calculated maximum air velocity and uses a pressure ratio to calculate air flow rate. Some users prefer to use the newer, "Wylie-Streeter" method which uses a different formular and is based on subsonic or critical conditions and air flow direction.

Bentley generally recommends using the new default Wylie-Streeter method but it is ultimately up to your engineering judgement and/or local requirements. Review the details in the below article to help you decide which method to use for your situation. This option also enables you to better match results with other transient modeling software which may use one method versus another.

To switch between the Comolet method and the Wiley Streeter method, open the transient calculation options in the Properties grid and set the Air Flow Calculation Method:

New models will use the Wylie-Streeter method as the default. Models created before version 26.00.00.xxx will use the Comolet method to maintain continuity of results.

Information on this has been included in the following article: Modeling Reference – Air Valves

Improved air direction results for Air Valves

The air flow direction results for air valves have been improved to better follow the air flow curves, whether you are using orifice diameter or an air flow curve. Air pressure is now used to determine air flow direction and air pressure is more accurately calculated, which impacts air inflow and outflow rate. Additionally, the calculations no longer use water inflow rate as the air outflow rate.

Information on this has been included in the following article: Modeling Reference – Air Valves

New Air Valve Orifice Diameter calculator 

This enables you to easily use data from the manufacturer rating curve to calculate the equivalent diameter, so that you can then simply enter that diameter. This can be easier than defining the entire rating curve (which is always still an option, by selecting "Air flow curve" for the "Air flow calculation method")

This calculator is available either from the "..." button next to the inflow and outflow orifice diameter fields in the air valve properties, or from the Tools Menu > More > Air Valve Orifice Diameter Calculator

  

See this link for more information: Entering Air Valve Orifice Diameter Based on Manufacturer Data

Support for Air Valve Opening Delay

A new field has been added to air valves to enable you to enter a delay in the time it takes for an air valve to open, after the pressure drops below zero. In the air valve properties, find the property “Valve Open Delay (Air Inflow)”. The default value is zero, meaning the air valve opens as soon as negative pressure is calculated at the air valve.

Note: this open delay feature currently only works when the calculation option "Run Extended CAV" is set to false.

Information on this has been included in the following article: Modeling Reference – Air Valves

Transient Reporting enhancements

This release introduces several enhancements to transient reporting in HAMMER:

Export Multiple Transient Profiles to Excel

An Export feature has been added in the Profiles tab of the Transient Results Viewer where you can export multiple profiles from multiple scenarios to Excel.

In the Profiles tab of the Transient Results Viewer, click the Export button next to the Profile pulldown menu.

This will open a new dialog where you can choose a scenario, the time that you want to export the results, and the name of the profile.

There is a Preview button that you can see what numerical results will be displayed before you click the Export button to save the data to a CSV file, which can be opened in Excel.

This only supports profiles with animation data at this time. To generate animation data in transient profiles, open the transient calculation options and set “Generate Animation Data?” to True.

See this link for more information on this: Export HAMMER Transient Profile Data to CSV

Improved Appearance of Transient Profile Labels

The handling of element labels at the bottom of the transient profile has been improved. When you zoom in on a profile, the label size now remains the same (GIS style). That means that the labels in the profile will be more legible when zooming in on part of the profile.

The placement of the label is based on the location of the element along the profile. Where there are very short pipes, you may still see some overlapping.

See more information in this article: How can you change the appearance of the profile in the Transient Results Viewer?

List of elements in Time History and Extended Node Data sort in ascending order

The elements in the Time History and Extended Node Data tabs for the Transient Results Viewer are now sorted alphabetically in ascending order. This makes it easier to find elements in the pulldown menu, particularly when there are many reporting elements. 

Updated labeling for gauge and absolute pressure results

Labeling for gauge and absolute pressure results have been updated so that it is clear which value type of pressure results are displayed in the transient profiles, Time History graphs, and Extended Node Data graphs. Note the vertical axis label on the left side of the graph below.



Improved Handling of Pipes with Zero Initial Flow

When a pipe has an initial flow of zero or very close to zero (less than the Flow Tolerance transient calculation option) but it's Hazen-Williams C coefficient is 170 or higher, HAMMER now uses a more appropriate value for that pipe's Darcy-Weisbach friction factor, to avoid situations where a zero friction factor would otherwise be used.

See more in this article: What equation does HAMMER use to compute the Darcy-Weisbach friction factor (f)?

Other Enhancements

This release also introduces many other enhancements not specifically related to transient simulations (and also available in WaterCAD and WaterGEMS 2026).

Set annotations for specific scenarios in Element Symbology

You can now set a specific scenario when using annotations in Element Symbology. This enables you to easily compare results between two scenarios in a single drawing. When you create or edit an annotation in Element Symbology, there is an option to select a scenario.

If you create another annotation for the same property field, you can select another scenario to display the results. In the screenshot below, you can see the flow results at a pipe for two different scenarios. Prefixes were used to help differentiate between the results.



Text Output for Formula-derived User Data Extensions

It is now possible to create a formula-derived User Data Extension (UDX) that outputs text. Previously, only numeric output was supported, via the "Real (Formula)" data type.

For example, you could use the IIF (if-then) function to give a "pass" or "fail" value. It is also possible to edit existing text values using different text-based functions.

In the User Data Extensions manager, create a new UDX and set the Data Type to Text (Formula). Click the Formula cell and click the ellipsis (…) button.

The properties for the element you selected will be displayed on the left. The available functions will display on the right. You will be able to build your formula using these.

Note: when using enumerated fields (dropdown list) in the list on the left side as part of your formula, you can hover your mouse over them for a tooltip preview of the numeric ID values corresponding to each choice, which you would use in the formula. This provides a quick reference so that you do not need to exit your formula editor to go check the available enumerated values.

See more here: Creating Formula-Based User Data Extensions

 

Bentley Copilot

Bentley Copilot is a new conversational artificial intelligence (AI) assistant that provides contextual intelligence, guides users through workflows, searches relevant documents, makes changes to model inputs, and analyzes data inputs and outputs through natural language conversation. By enabling users to "talk" to their hydraulic models and removing the need to memorize tool locations or complex query syntax, Bentley Copilot empowers users and accelerates project delivery, reducing the learning curve and enabling users to focus on engineering decisions.

To access Bentley Copilot, click on the Bentley Copilot item in the Home tab of the Ribbon interface. This will open a dialog where you can start the chat with Copilot.

Note: If you do not wish to install Bentley Copilot, it can be disabled during or after installation. See details in the article below.

 

Prompts can include asking for general information about the model (“how many pipes are there with a diameter greater than 12 in?), model functionality (“compute the active scenario”), how-to type questions (“how can I model a connection to an existing water main?), and more.

With this release, Bentley Copilot is offered as a Technology Preview, which means that it is still under development and may not represent the full functionality intended for a future (non-tech preview) release. Therefore, please use this feature for evaluation purposes. Please be aware that at some point, you may receive notice from Bentley that such use must cease or this Technology Preview will become unavailable to you. As we receive feedback, this Technology Preview may also be enhanced, updated or also discontinued without notice. As a Technology Preview, it is provided to you "as-is" without the benefit of any Bentley warranty, indemnity or support obligation.

More details can be found here: [Tech Preview] Using Bentley Copilot in OpenFlows Products

iModel Connector

This version introduces an iModel Connector, to synchronize a hydraulic model to Bentley's Infrastructure Cloud. iModel Connectors provide a bridge to transform data into the standard iModel format, which can be viewed in Bentley Infrastructure Cloud (BIC). This can help with a number of workflows such as performing clash detection across different programs (like OpenFlows Water and OpenFlows Sewer), as well as provide a method a model to be viewed without the need to own the OpenFlows product.

Note: results are currently only exported for the current timestep of the initial conditions, as time-series (EPS) results are not yet supported in the iModel format. You can also use statistical transient results such as the maximum and minimum HGL, pressure, etc.

Details on using this workflow can be found here: Using iModel Connector in the OpenFlows products

Example of an iModel as viewed in Bentley Infrastructure Cloud:



Graphical Editor Performance Improvements

Performance of the graphical editor has been improved and optimized. Mouse-based operations such as panning, zooming and dragging selected objects should feel faster and more responsive especially in large models.

These improvements do not introduce visual or functional differences compared to previous versions.

Improved support for FlexTable filters in Custom Reports

A Filter option has been included in the FlexTable section for Custom Reports. This will improve the use of filters for FlexTables in Custom Reports. There are options to use the current filter, a custom filter, or no filter.

Information on using Custom Reports can be found here: Creating Custom Reports

Export elements decoration lines (dashed lines) as shapefiles

An export option has been included that will export the decoration lines that show the dashed line links between elements into shapefiles. This is available in both the Standalone and ArcGIS Pro platforms. To access this, click on File and then choose Export > Decorations.

These decoration links include the dashed lines between catchments and outflow nodes or isolation valves and pipes, among others.

Additional information on this can be found here: How to Export Element Decoration Lines as Shapefiles

Additional functionality, such as Zoom To and Export, added to Alternatives

Zoom To and Export functionality has been included for Alternatives. These features are available in other places in the program, like FlexTables. Including this in the Alternatives manager gives you additional options for viewing and editing elements and element data.

To export data to a shapefile, text file, or CSV file, click the Export to File button in the upper left of a given alternative.

The Zoom To functionality works like it does in FlexTables or User Notifications. You can right-click on a row and choose Zoom To, which will highlight that element in the drawing.

Export to Word feature added to Graph and FlexTables

A new Export to Word feature has been included for Graphs and FlexTables. When you open a graph or FlexTable, you will find an Export to Word feature. This will export the graph or FlexTable to a new Word document.

Note: for Graphs, the export to Word feature is currently only available for EPS graphs in HAMMER (initial conditions). Exporting Time History graphs from the Transient Results Viewer is not yet supported but may be in a future release.

This functionality streamlines the process of creating reports and sharing model results, as you can now seamlessly integrate tabular data and graphical plots into your project documentation.

Furthermore, you can customize the appearance of the exported content using Chart and Table Templates. For graphs, the underlying data remains accessible in the Word document and can be edited via Excel, offering greater flexibility for reporting and presentation.

For graphs, you can also edit the data source by right-clicking on the graph in Word and choosing Edit Data, which will open the numerical data in Excel. For example, you could adjust the column header to display differently in the Word document compared to the graph in the OpenFlows product.

See this link for more information: How to Export FlexTables and Graphs to Microsoft Word

Improvements to Report Output

Several improvements have been made reporting, to improve the quality and clarity of report output. These improvements primarily focus on the reports seen when clicking the Report button from places like Flextables, the Report menu, and printouts of the plan view.

Google Maps replacing Bing Maps background layer

Google Maps tiles are replacing the Bing Maps background layer, because Bing Maps is being deprecated by Microsoft:

The overall use and functionality are otherwise the same and the feature is now simply referred to as "Background Map".

No conversion or extra steps are needed for existing models that previously used Bing Maps.

Updated Installation file with Deployment Image Support

This release uses the standard Bentley installation technology, which supports the creation of a deployment image for mass/silent deployment. This is done using the /layout switch when running the installation executable, to configure and create a .lyt file with your deployment preferences. See more details here:

Compatible Platforms and Operation Systems

Compatible Operating Systems:

Supported Platforms:

ProjectWise integration:

Support for ProjectWise 2025, 2024, 2023 and CONNECT Edition

See: Platform Compatibility

Model Compatibility 

Older models can be opened in this version of HAMMER.

See: Model backward / forward compatibility

Stability enhancements and fixes to reported issues

As with all new versions, this release includes fixes to various user-reported issues from the previous release, providing an overall more stable experience.

See Also

HAMMER TechNotes and FAQs

Downloading OpenFlows / Hydraulics and Hydrology Software