Select a category of Frequently Asked Questions or just search the page for what you want.

Top reasons to use WaterSums
Switching to WaterSums
Comparing with other tools
WaterSums Software
Installation problems
Versions and Upgrades
Customisation or special development

Top reasons to use WaterSums

Why would I choose to use WaterSums?

WaterSums is easy to use, professional, reliable and cheap. Development continues to progress and WaterSums is responsive to customer requirements or requests.

Can I rely on the results I get from WaterSums?

WaterSums network analysis uses the well tested and respected EPANET Toolkit for hydraulic and quality analysis, so the results can be relied upon.

Do I need expensive hardware to run WaterSums?

WaterSums runs on cheap, easily available PC hardware running Windows.

Is WaterSums developed by professionals?

Yes. WaterSums is developed by professional engineers with many years’ experience in developing technical software.

I’m in a hurry? Can WaterSums help?

Yes. WaterSums has a free 30-day trial of the full product, so you can start working with WaterSums immediately – and because of the low purchase price, most customers can complete the final purchase before the 30-day trial expires. If you’re in a hurry, WaterSums is the answer.

I want some special customisation – will WaterSums oblige?

See answer here.

Switching to WaterSums

How do I switch to WaterSums?

Easy: Simply download and install WaterSums, taking advantage of the 30-day free trial. Most software that supports analysis of water supply networks will export network information in EPANET file formats, and WaterSums provides drag’n’drop import of EPANET files to make the changeover simple.

Are there any simple WaterSums features I can try?

Yes. Try the easy user interface with intuitive project tree and search facilities. Try the easy editing facilities which check many of the values you enter to save time. Notice the ‘Auto-Analyse’ feature that shows if the network is invalid at any time during editing; no need to wait until you run the analysis to find that you made a simple mistake. If you use rules, why not try the rule editor with its syntax highlighting and syntax checking?

Try some of the extra tools of WaterSums which help so much with visualising what is really happening in your network:

  • Automatic contour generation – now you know the ground levels and slopes.
  • Pipe flow direction visualisation: it’s so much easier to visualise the flow in the network.
  • Visualisation of the water level in tanks gives you a better feel for where the water goes.

Is there a tutorial?

Yes. WaterSums comes with an introduction for new users, including a simple tutorial which can be viewed from the Downloads page.

Does WaterSums provide help?

Yes. Context-sensitive help is available within WaterSums. The help file is updated with each release of WaterSums to include new and enhanced features and it can be downloaded directly from the Downloads page. WaterSums also performs plenty of checking of data values entered, so that clear explanations can be provided by the application when data is invalid.

Will WaterSums work with my EPANET network files?

Yes. WaterSums imports EPANET network files (.NET) or input files (.INP) through opening the files or simply dropping them on the WaterSums project tree. It couldn’t be easier than that!

Comparing with other tools

What software tools are similar to WaterSums?

There are several other software tools that perform similar analysis to WaterSums. First, there is
EPANET – public domain software developed by the USA EPA’s Water Supply and Water Resources Division. WaterSums uses the analytical engine (the EPANET Toolkit) from this public domain software, so the analytical results should be the same. However, a simple Windows program is also available from the EPA which uses the same engine and provides a useful editing and review interface. EPANET does not provide transient (water hammer) analysis.

Please note that there is no association between WaterSums and any of the software or companies named below. There is no implication of support for WaterSums by any of these companies in the use of their names which are provided solely to assist potential customers of WaterSums. Likewise, WaterSums is not implying any support for these companies by listing them here. The names of companies or products may be trademarks of their respective owners.

Other network analysis software tools are also available with various different characteristics:

  • Some use the EPANET engine, while other software provides its own analysis engine.
  • Some integrate with Autodesk Inc AutoCAD®, or Esri® ArcGIS® software platforms.
  • Some do not include transient (water hammer) analysis, while others make it available as an integrated or standalone option at extra cost.

A list of common network analysis software is shown below. If there is no specific note, you can assume that the software includes water hammer analysis as well as extended time analysis. If any corrections are required, please advise as soon as possible.

WaterSums Software


Does WaterSums run on MacOS X or Linux?

No. WaterSums currently runs only on Microsoft Windows.

Does WaterSums run on 64-bit versions of Windows?

Yes. WaterSums runs on Windows Vista and Windows 7 64-bit versions. On 64-bit operating systems, network analysis is done in full 64-bit mode, but all other operations are still 32-bit due to limitations of Microsoft Silverlight and the Adobe SVG Viewer.

How many pipes can I analyse with WaterSums?

There is no software-imposed limit on the number of nodes or links in a network. Any size limits will come from hardware limits like the amount of memory available.

Can I import my EPANET input files?

Yes. WaterSums can import EPANET input files and turn them into full projects. The only limitations are that if coordinates of nodes have not been given, they will not be able to appear on the network map until they are given coordinates. A WaterSums project can contain more than one network, so you might want to group them together in related areas.

Can I import my EPANET network files?

Yes. WaterSums can import EPANET network files into an existing project or into a new project. WaterSums project can contain more than one network, so you might want to group them together in related areas.

Can I export my networks into EPANET format?

Yes – as network files or as input files – it’s up to you.

Can I use my saved patterns from EPANET?

Yes. The pattern editor has a Load button to load saved EPANET patterns.

Can I use my saved curves from EPANET?

Yes. The curve editor has a Load button to load saved EPANET curves.

Does WaterSums help with editing node/link rules?

Yes. WaterSums provides a rule editor for editing simple and rule-based controls. With auto-completion, syntax highlighting and syntax checking, the task of creating rules has never been easier. What is more, if you refer to a node or link that does not exist, WaterSums gives you a warning immediately. And if you need help, the help is shown directly below where you define the control.

Does WaterSums help me track down network problems?

Yes. Network errors and warnings are displayed in a window with links to allow editing of the node or link causing the problem.


Can I report a bug?

Yes. WaterSums makes it easy to report any bugs you may find. Simply select Help > Report an issue… and enter the details in the WaterSums Issue tracker. Alternatively, you can go directly to the Issue tracker here.


Does WaterSums build on any other software components?

Yes. In the development of WaterSums we are like dwarfs standing on the shoulders of giants. We appreciate the open source and freely available software that has made the development of WaterSums possible – in both the time it has taken and the staff required. In appreciation of these giants, WaterSums has made a commitment to maintaining a very low price – with a particular desire to be helpful in developing countries where the design of water supply networks continues to become more and more important.

From time to time, WaterSums developers make contributions to open source software (normally to fix bugs), and contributions to available knowledge through the WaterSums blog. For example, one of the popular pages on this site is Adobe SVG Viewer and mousewheel zoom (Part I). As we stand on the shoulders of these giants, we thank them for their gifts and try to give as well as take.

The open source or freely available software components used by WaterSums are listed

We believe that all software components are acknowledged appropriately in WaterSums, but if there are any questions about this, please let us know.

Installation problems

My download of WaterSums hangs and eventually times out

If you are using Vista or above and have problems with the download hanging and then timing out, try running the following command as Administrator:

netsh interface tcp set global autotuning=disabled

This slows down the download a little by removing autotuning to optimize speed, but makes it more likely to succeed.

Can I run WaterSums on Windows 8.1 Preview?

Yes, WaterSums can be installed and has been tested a little on Windows 8.1 Preview 32- and 64-bit versions. However, since WaterSums is not signed, Internet Explorer 11 will try to discourage you from running the installer. Look for the extra options you are offered on the dialog and tell Windows to install the software anyway despite the warnings about an unrecognised publisher. WaterSums will work with Windows 8.1 and IE11 as long as one of the default security settings is changed as described below in the process below.

When visiting the WaterSums website with IE11, the downloads page will indicate that:

  • .NET 2.0 is installed. This is not correct, but will be fixed later in the installation process.
  • you need Internet Explorer 6 or newer. There will be no indication regarding the version of IE you have installed because IE11 does not include the MSIE identification string.
  • Silverlight 5 also needs installing (unless you have already installed it). The Microsoft webpage reports that the browser is not fully compatible, but offers the option of installing the plugin anyway. Run the installer. The web page will still report that the plugin is not installed, but this can be ignored.

To install WaterSums 1.2:

  1. Click on the “Install WaterSums!” link.
  2. Select “Save” to save setup.exe when prompted.
  3. A bar at the bottom of the IE window will warn that “Setup.exe is not commonly downloaded and could harm your computer.”
  4. If you are willing to trust WaterSums, press the “Actions” button.
  5. A panel will be displayed: “SmartScreen Filter – Internet Explorer”
  6. Press the “More Options” button and then press the “Run Anyway” button when it is shown.

  7. A panel will be displayed: “Application Install – Security Warning” advising that the “Publisher cannot be verified” and asking “Are you sure you want to install this application?” The software publisher is given as “Unknown Publisher”. Press the “Install” button.
  8. After the download completes, another panel will be displayed: “Open File – Security Warning”
  9. This panel also warns that “The publisher could not be verified. Are you sure you want to run this software?” The publisher is again listed as “Unknown Publisher”.
  10. Remove the tick from the checkbox: “Always ask before opening this file”.
  11. Press the “Run” button.
  12. You will then be advised that the app on your PC requires a Windows feature, the “.NET Framework 3.5 (which includes .NET 2.0 and 3.0)”.
    Press the “Download and install this feature” button.
  13. .NET 3.5 will be installed which includes .NET 2.0 as required by WaterSums.

  14. You will now need to make sure that the Internet Options are set correctly as detailed below.

Once you have installed the software, it should run. However, if you are working with default internet settings in Windows 8.1 and IE11, when you try to display a network map in WaterSums, an error will be displayed telling you “Error: [ScriptObject_InvokeFailed]”. To fix this problem, go to the Windows start screen (press the “Windows” key) and then:

  1. Type “Internet Options”
  2. Select the “Internet Options” entry in the search results
  3. Select the “Security” tab on the Internet Options panel
  4. Select “Internet” in the list of zones.
  5. Make sure the zone is set for the default security level (the level should be set to “Medium-high” and the “Default level” button should be disabled). If it is not, press the “Default level” button to reset the security levels and then “Apply” them.
  6. Press the “Custom level…” button
  7. Under “ActiveX controls and plugins” branch, enable “Initialize and Script ActiveX Controls not marked as safe for scripting (not secure)”.
  8. Apply the changes and close the Internet Options panel.

WaterSums should now run successfully, although it has not been thoroughly tested yet.


Is WaterSums free or open source software?

No. The WaterSums source code is not freely available and a license is required for ongoing use of WaterSums. Purchasing is easy here.

Can I have a free trial of WaterSums?

Yes. The available WaterSums software download allows free usage for 30 days. After the 30 days is complete, a licence must be paid for or you must stop using WaterSums.

Is the WaterSums licence long and impossible to understand?

We have tried to keep it clear and simple. You can read it here.

Does WaterSums require a dongle or hardware lock?

No. However, to run WaterSums after the 30 day trial period, you do need a licence key file provided by WaterSums. This key file identifies the PC running the software. If there is a hardware upgrade, failure or replacement necessary, a replacement key may also be required. Such keys are available on request from WaterSums free of charge to registered users for up to 5 years after the sale of a licence (on a reasonable use basis). After 5 years, WaterSums reserves the right to charge a processing fee to generate replacement keys if required. A paid upgrade restarts the 5 year clock.

Versions and Upgrades

Do I get any free upgrades?

Upgrades within the same minor version are free for 4 months after the purchase of a new licence. See here for details. If you choose to pay for software maintenance, you will not have to pay for any major, minor, incremental or bug fix releases.

Do I have to pay for upgrades?

If you choose not to pay for software maintenance, upgrades to new major and minor versions are always chargeable. Any incremental or bug fix releases within the same minor version are free for the first 4 months and chargeable after that. See here for details.

What about bug fixes?

Bug-fixes included in emergency patches or upgrades in the same minor version are free for the first 4 months after the purchase of a new licence. If you choose to purchase software maintenance, all releases are free during the maintenance period. See here for details.

Do I have to pay annual software support and maintenance fees?

No. WaterSums licences are perpetual licences, but a keyfile is required to run (see Does WaterSums require a dongle or hardware lock?). You may, however, choose to pay for annual software maintenance as this provides access to all bug fixes and upgrades that are released as well as more extensive technical support.

Is software support available?

Yes. Some limited software support is available through the contact form and the issue tracker on this website. If significant software support is required, this is charged on an hourly basis.

Customisation or special development

Is WaterSums open to proposals for specific customisation or modification of development schedules?

We are always open to such proposals, although they always must be balanced against our need to satisfy customers who have made decisions based on published development schedules. If you have specific requirements or desires, and are willing to pay hourly rates for custom development or adjustment of the existing published development schedule, contact us at WaterSums. We always reserve the right to refuse any requests on technical, aesthetic or moral grounds. In general, any customisation must be easily accommodated within the application so that there is no need to maintain multiple code streams.