Changelog for TUFLOW FV 2026.0.0

Release date: 27 Mar 2026

Build: 2026.0.0

General Notes
Backwards Compatibility
New Features and Enhancements

General Notes

The 2026 TUFLOW FV release includes a range of software updates. These include enhancements to the Destratification Unit Structure Type, Additional Diagnostic Outputs, Updates to Output Units in CSV files and TUFLOW FV Build Process Updates for both CPU and GPU builds.

The release also includes updates to installation and supporting tools. A new Windows installer option has been introduced and Linux installation packages have been updated, including revised .rpm and .deb support for modern Linux distributions. In addition, the Get Tools package within the TUFLOW FV Python Toolbox environment has been updated to improve workflows and increase compatibility with global and regional atmospheric, tidal and ocean models.

This release also includes the new online TUFLOW FV User Manual and supporting New eLearning Courses. Together, these expand the range of free supporting content available for new and existing users. A suite of Hydraulic Structures Example Models has also been added to the TUFLOW FV Wiki to further support learning and model development.

The release notes that have previously accompanied each TUFLOW FV release have now been superseded by this changelog. Each major and minor TUFLOW FV release will also have an accompanying TUFLOW FV User Manual.

Backwards Compatibility

The 2026.0.0 release includes TUFLOW FV Build Process Updates and minor changes in results may occur when upgrading from previous releases. Testing to date has shown negligible changes. However, users should complete independent upgrade testing and compare results between the old and new versions when migrating an established model.

If upgrading from previous releases, users should be aware of the Updates to Output Units that have been applied across the Advection Dispersion (AD), Sediment Transport (ST) and Water Quality (WQ) modules. These changes will affect the interpretation of modelled output values and users should refer to the relevant tables in the Updates to Output Units section for more information.

New Features and Enhancements

New TUFLOW FV User Manual

The new TUFLOW FV User Manual is now delivered in an online format. It includes interactive features such as searchable tables, linked content and navigation tools. Before using the new manual, users are encouraged to review the How to use this manual section.

TUFLOW FV Build Process Updates

The TUFLOW FV 2026.0.0 release has been built using the current Intel oneAPI Fortran compiler (ifx), replacing the legacy ifort compiler to maintain ongoing support and compatibility with modern systems. This is a build system update only and does not change model configuration or workflows. Testing confirms that results remain consistent with previous releases within normal numerical precision, so changes in model outputs as a result of this upgrade are not expected.

The TUFLOW FV GPU module build process has been updated from CUDA 11.8 to CUDA 12.9. This maintains compatibility with current NVIDIA hardware while continuing support for GPUs supported in the TUFLOW FV 2025 releases. GPU users may need to upgrade their NVIDIA drivers to meet the minimum driver requirements for CUDA 12.9.

The Windows build has been tested on Windows 10 and Windows 11. The Linux build has been tested on Ubuntu 22.04 and Rocky Linux 9, with both .deb and .rpm installation packages available, as well as a .tar.gz tarball. The .rpm package is built for modern RHEL 9-compatible distributions and will not run on legacy variants such as RHEL 7 or CentOS 7. Similarly, the .deb package targets modern glibc 2.35+ environments and is not compatible with legacy distributions such as Ubuntu 18.04 or Debian 10.

Windows Installer

In addition to the portable distribution in .zip format, TUFLOW FV is now distributed as a .msi Windows Installer package. Use of the installer should be familiar to Windows users. The installer is available for download via TUFLOW Downloads.

The installer allows customisation of the installation location, but it is recommended to use the default location.

The installer offers to install TUFLOW FV either for all users on the computer (‘Everyone’), which requires elevation as local administrator, or for a single user (‘Just for me’). When installed for all users, the default location for TUFLOW FV 2026.0.0 will be in the standard ‘Program Files’ e.g. C:\Program Files\TUFLOW\TUFLOW FV 2026.0. When installed for a single user, the location will be inside the user’s profile e.g. C:\Users\tuflow.user\AppData\Local\Programs\TUFLOW\TUFLOW FV 2026.0\. In either case, a shortcut to this location will be added to the Windows Start Menu, together with shortcuts to the manual and the licence agreement.

If there are patches for the TUFLOW FV release, i.e. TUFLOW FV 2026.0.1 etc., they will automatically replace the installed version. Patches generally do not affect outputs and are intended to fix bugs. New releases will not replace the previous installed versions. For example, the TUFLOW FV 2026.1.0 will not replace TUFLOW FV 2026.0.x; users can use 2026.0 and 2026.1 side-by-side. The same applies to major upgrades like 2027.0.

The interactive installer requires the user to read and agree to the End User Licence Agreement (EULA). However, if an organisation wants to distribute the application through a software portal or install in an automated fashion, administrators can use the standard msiexec to ‘silently’ install and provide consent after reading the EULA, as well as uninstall:

msiexec /i tuflowfv-2026.0-2026.0.0-1.msi /qn IAGREE=Yes
msiexec /x tuflowfv-2026.0-2026.0.0-1.msi /qn

Or for the current user without elevation:

msiexec /i tuflowfv-2026.0-2026.0.0-1.msi /qn IAGREE=Yes MSIINSTALLPERUSER=1 ALLUSERS=2
msiexec /x tuflowfv-2026.0-2026.0.0-1.msi /qn

Note: add /l*v install.log for troubleshooting installation with msiexec.

Note: the .msi, as well as all the binaries that are installed, have been digitally signed with a certificate from a trusted CA (GlobalSign), allowing security suites to include exceptions for its thumbprint.

Linux Installation Package Updates

Linux installation packages have been updated to use a revised directory structure. TUFLOW FV binaries and libraries are now installed under /opt/tuflow/<version>/bin and /opt/tuflow/<version>/lib, with a launcher script placed in /usr/bin.

This replaces the previous /usr/local/bin/<version> and /usr/local/lib/<version> layout, with the launcher script also previously stored under /usr/local/bin. The updated structure improves support for versioned installations and aligns more closely with standard Linux packaging conventions for TUFLOW FV .rpm and .deb distributions.

Refer to the Linux Installation Guide for installation instructions and additional detail.

Enhancement of Destratification Unit Structure Type

Airflow rate for bubble plume destratification devices can now be applied at atmospheric pressure or at plume nozzle pressure. Destratification units can also be operationally controlled to temporally vary airflow rate. See the TUFLOW FV Manual for details.

The general arrangement of the bubble plume.

Outputs from the TUFLOW FV bubbler calculations are written to the structflux output block.

Updates to Output Units

Updates to the polyline flux, structure flux, mass and bubble plume output units have been applied across the Advection Dispersion (AD), Sediment Transport (ST) and Water Quality (WQ) modules.

The following tables summarise the previous and new units for polyline flux (Table 1), structure flux (Table 2), mass (Table 3) and bubble plume (Table 4) output types. Users should be aware that these updates will change the modelled output values.

Table 1: Polyline (Flux) output units

Polyline (Flux)
Variable	Previous units	New Units
Salinity	PSU m³/s	tonnes/s
Temperature	degrees Celsius m³/s	no change
Tracer	Units m³/s	tonnes/s
Suspended sediment	mg/L m³/s	tonnes/s
Bedload sediment	mg/L m³/s	tonnes/s
Constituents simulated in mg/m³	Concentration m³/s	kg/s
Constituents simulated in g/m³	Concentration m³/s	tonnes/s
Constituents simulated in 10⁴CFU/m³	Concentration m³/s	Tera CFU/s

Table 2: Structure output units

Structure
Variable	Previous units	New Units
Salinity	PSU m³/s	tonnes/s
Temperature	degrees Celsius m³/s	no change
Tracer	Units m³/s	tonnes/s
Suspended sediment	mg/L m³/s	tonnes/s
Constituents simulated in mg/m³	Concentration m³/s	kg/s
Constituents simulated in g/m³	Concentration m³/s	tonnes/s
Constituents simulated in 10⁴CFU/m³	Concentration m³/s	Tera CFU/s

Table 3: Mass output units

Mass
Variable	Previous units	New Units
Salinity	psu m³	tonnes
Temperature	degrees Celsius m³	no change
Tracer	Units m³	tonnes
Suspended sediment	mg/L m³	tonnes
Constituents simulated in mg/m³	Concentration m³	kg/s
Constituents simulated in g/m³	Concentration m³	tonnes/s
Constituents simulated in 10⁴CFU/m³	Concentration m³	Tera CFU/s

Table 4: Bubble plume output units

Bubble Plumes
Variable	Previous units	New Units
Flow	Not reported	m³/s
Salinity	Not reported	tonnes/s
Temperature	Not reported	degrees Celsius m³/s
Tracer	Not reported	tonnes/s
Suspended sediment	Not reported	tonnes/s
Constituents simulated in mg/m³	Not reported	kg/s
Constituents simulated in g/m³	Not reported	tonnes/s
Constituents simulated in 10⁴CFU/m³	Not reported	Tera CFU/s

Additional Diagnostic Outputs

The following additional diagnostic outputs are available:

Water mass timeseries (tonnes), in mass output type
Potential energy timeseries (GJ), in mass output type
Water volume entrainment rate per bubble plume diffuser structure timeseries (m³/s), in structflux output type
Mass entrainment rate of every simulated constituent per bubble plume diffuser structure timeseries, in structflux output type. Units are presented in Table 2

Auto Terminate Feature

The Auto Terminate feature automatically stops a simulation once a specified water level threshold is reached at a user-defined monitoring location. This can be used to save time and computational resources by ending simulations once the target condition is met, such as a flood event reaching a critical level or a water level rising above a certain threshold.

Write XMDF Files Using HDF5 Library

TUFLOW FV now writes XMDF outputs by utilising the HDF5 library directly rather than the intermediary XMDF library. This allows the use of the most up-to-date HDF5 library while still producing equivalent output files.

Cell Wet/Dry Depths Syntax Update

To standardise with TUFLOW HPC/Classic, support for Cell Dry/Wet Depth and Cell Dry/Wet Depths has been removed. These were previously accepted as alternative syntax for Cell Wet/Dry Depth and Cell Wet/Dry Depths, but are no longer supported.

The following commands are supported: Cell Wet/Dry Depths, Cell Wet\Dry Depths, Cell Wet/Dry Depth and Cell Wet\Dry Depth.

The recommended syntax is:

Cell Wet/Dry Depths == h_dry, h_wet

For example:

Cell Wet/Dry Depths == 0.001, 0.02 ! {1.e-5} Dry depth (m or ft), {1.e-2} Wet depth (m or ft)

Get Tool Updates

The Get Tools package within the TUFLOW FV Python Toolbox environment has been updated to help modellers download and format boundary condition data commonly used in TUFLOW FV.

The latest updates and enhancements to Get Tools include:

Get Tide, Get Atmos and Get Ocean have been merged into a new package tfv-get-tools.
Get Tide supports the global tide models FES 2014 and FES 2022b from the Finite Element Solution Global Tide model (FES) distributed by AVISO.
Get Ocean has been expanded to include an additional ocean model from Copernicus Marine.
Get Atmos has been updated from the BARRA atmospheric model to BARRA2 produced by the Bureau of Meteorology.

This release of Get Tools is accompanied by a new suite of TUFLOW FV Wiki tutorials demonstrating how to use the latest tfv-get-tools package:

Visit the TUFLOW FV Get Tools Update and Installation Wiki for instructions on how to install or update the latest tfv-get-tools package.

New eLearning Courses

Our eLearning courses now include:

The foundational courses TT000(E): TUFLOW Product Suite - Software Setup and TT001(E): TUFLOW Product Suite - QGIS Introduction have been updated to cover the software setup and QGIS introduction skills required for the TUFLOW Product Suite.
TT200(E): TUFLOW FV - 2D Model Build introduces the key skills required to create a TUFLOW FV 2D hydrodynamic model
TT201(E): TUFLOW FV - Meshing Introduction provides foundational skills in mesh building.

To access the full range of eLearning content, visit the Training Course Catalogue.

New Example Hydraulic Structures Models

An additional suite of example models demonstrating the configuration of hydraulic structures has been added to the Example Models page on the TUFLOW FV Wiki. To access these models, visit the Example Hydraulic Structures Model section.

The examples include:

Hydraulic structures (e.g. weir, culvert) with multiple connection types (nodestring, linked nodestring and linked zones).
Temporally variable bathymetry with multiple control types (trigger, timeseries, sample rule, target rule).
Flux function with multiple control types using nodestring.