lbutler 2 hours ago

Currently the two largest vendors of hydraulic modelling software are Autodesk and Bentley. Both have taken the EPANET engine and created private forks in the 90s/2000s and never contributed back.

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

xnx 11 hours ago

> And epanet-js is a tool that you can run in a browser - full simulations with a WASM-based engine. It’s competing with expensive old-school software that costs $16,000 a year, runs exclusively on Windows, is priced by “pipes”, and uses the same engine, EPANET. This is so much better in comparison. A radical improvement.

I have absolutely no use for epanet-js, but this is so cool. Exactly what free software is supposed to do.

  • jessekv 9 hours ago

    I suppose it's correct to say EPANET competes with expensive commercial offerings, but it's actually available completely free:

    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.

bilekas 6 hours ago

This is really cool and fair play to him/them for doing this..

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?

  • 9dev 4 hours ago

    It grants them a two-year headspace in which licensees are prohibited to create a competing offering based on the open sourced code—so e.g. Amazon can't just take the source code and create a paid offering within AWS without contributing to upstream—at least for two years after officially licensing the software.

    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.

jannes 2 hours ago

So cool! I wonder if I can use this software to plan an irrigation system for my garden.

Does the simulation also work on a smaller scale?

vinnymac an hour ago

Surprised how well this worked on my 8 year old phone despite mobile support being in preview, very well done.

jalk 5 hours ago

I was under the impression that municipalities use GIS systems to contain "everything" (sewers, water and gas pipes, and the electricity,telephone,fiber cables etc) Is that just a pipe dream (no pun intended) or do those lack the simulation part ?

  • lbutler 4 minutes ago

    The GIS system is generally the base for a hydraulic model. You use that data to build a connected graph structure that the hydraulic engine, EPANET, uses to run calculations to figure out the pressure at the nodes and also flow rates in pipes.

    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.

    [0] https://www.epa.gov/water-research/epanet

    [1] https://www.cityofkyle.com/media/69766

  • WouterSpaak 4 hours ago

    I'm no physicist, but I've worked as a software engineer on energy (and drinking water, which EPANET simulates) infrastructure network design tooling for the last six or so years. It has been my understanding that simulating and validating multimodal network designs, which take into account electricity, gas consumption, district heating, is extremely difficult.

    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.

  • p_l 5 hours ago

    Some might in fact contain everything, but the core difference is that this is a simulation engine not a GIS tool.

PoissonVache 3 hours ago

What's the business plan ? Why don't make it like 20$ a month ? Are your working in a company that needs this 16000$ software, so they are just happy to cut the fees and don't care about making it opensource ?

stared 4 hours ago

My first thought - is it possible to use Epanet.JS to create a browser-based SimCity-like game?

  • neurostimulant an hour ago

    Epanet is used to stimulate water flow and pressure loss (head loss) in a pipe network so you can design a pipe network that meets your water flow and pressure requirements. It probably can be used in a city game if that game has water distribution network component.

iachilo 7 hours ago

Never heard of EPANET nor did I know that drinkable water systems had a specialized software. That's a great early hour knowledge.