The commercial tools have made it easier for engineers at consultancies and utilities to build hydraulic models by integrating GIS and providing support for scenarios to compare different states of the model or future developments of a city.
Though as Tom points out, this comes at a huge price.
The US EPA does offer a simple GUI which can be used for smaller systems but without a connection to GIS, its usage has been limited.
These commercial versions have become enterprise monsters, they are very complex and expensive.
We wanted to create the right balance between what the US EPA already gives away for free and what the big vendors offer. We believe that releasing the software as FSL which transitions to MIT gives us the right head start and for the advanced features we're charging about 10% of what Autodesk and Bentley do - and for those that think that's too much, they of course can download and host their own private version too.
For those that are still curious, here are some extra links and context.
https://app.epanetjs.com/ – Try the app, it's local first and registration optional
https://github.com/epanet-js/epanet-js – Here is all the source code
https://github.com/epanet-js/epanet-js-toolkit – See how we converted the C engine to WASM
https://epanetjs.com/ – Read a landing page to see what we're doing and why, also our pricing
https://www.autodesk.com/products/infowater-pro/overview – Autodesk's product $10k/yr/user
https://en.virtuosity.com/openflows-water – Bentley's product $16k/yr/user
I have absolutely no use for epanet-js, but this is so cool. Exactly what free software is supposed to do.
https://www.epa.gov/water-research/epanet
I know someone who uses it to design clean drinking water distribution systems in rural communities in Central America. They would not be able to do what they do if they had to pay for an expensive commercial licence.
Desktop EPANET is still windows-only though, so having a browser version is pretty cool.
One thing I don't understand though is the license.
> Fully open source (MIT) after two years under our Functional Source License (FSL).
What exactly does this mean?
You can read the FSL license text here: https://github.com/getsentry/fsl.software/blob/main/FSL-1.1-...
Sounds like a reasonable tradeoff to ensure companies don't have immediate disadvantages from open sourcing their code.
Does the simulation also work on a smaller scale?
There is also a water quality component where you can calculate the age of water in the system or chemical, such as chlorine, or other by-products you may or may not want in the system.
The US EPA site goes into technical details on what the engine can do [0], but the vast majority of modeling is done as part of a water master plan for a water utility.
A water utility will build a hydraulic model of their network and calculate and model the growth of their city over a 30-year period. The model will highlight areas of concern, generally low pressure, and the water utility can propose new infrastructure like larger pipes, tanks, or pumps, and will schedule future capital works to keep service levels acceptable.
They generally repeat this process every 3–5 years, rebuilding the model and rewriting their master plans. Here is an example of a master plan by the City of Kyle [1].
Generally, a water utility is proposing tens of millions of capital works, if not more. So traditionally, the high price tag has just been accepted. But obviously, this doesn't scale down to smaller utilities, and normally consultants will do the work on their behalf, including holding the right software license.
Municipalities definitely have systems that document where everything already is under the ground (though especially in Europe there are many older cities where the data of old pipes is lacking), but for designing new energy networks, an "everything" simulation and solving model is very, very complex.