Has anyone else had that old-school professor at Uni talking about how in the early days of hydroinformatics they were developing their own numerical schemes, testing for the performance, running on tools they developed that looked like MS-DOS and spent hours looking at the simulation running (the kind that would take a few minutes today) whilst smoking and drinking coffee?
We came a long way since then: from those early ages, free tools various agencies develop and distribute for free (thank you EPA and USACE and USBR and FHWA) to the very same tools on steroids sold for big bucks.
A recent project in Uganda is a case in point. A water supply system serving over 30,000 people across health centres, schools, and seven villages. Multiple demand nodes, varying topography, a pumping arrangement, and storage tanks sized for various daily demand patterns, depending on the user. The project was initially developed in EPANET with all the advantages and downfalls, which was used as the basis for pipe sizing and final design.
EPANET is the software we all opened at Uni and thought how bad the GUI was. But hey, it was free, fast and it was doing what it was supposed to do (which is perhaps even better for learning purposes). It was last updated in 2020 for version 2.2, and the GUI still has that 90s feel.
Nowadays, pressure systems hydraulic modelling has been dominated by expensive commercial packages where licences run into thousands of dollars annually, not to mention training. And for consultants working on projects, choice is often limited to whichever software their client or compliance-giving authority uses to maintain their “digital twins.”
The irony is that the underlying algorithm most of these commercial packages rely on is EPANET, developed by the US Environmental Protection Agency and released as public domain software.
The modelling capability is free; what you’re paying for is the interface, the support, and the ecosystem built around it.
For development projects, this cost barrier is a fundamental problem. Rural water supply projects in places like Uganda operate on constrained budgets and every dollar spent on consultant software licences is a dollar not spent on pipes, pumps, or training local operators. And many wealthy but budget-conscious clients think the same way.
Open-source tools change these economics. They allow local engineers to use and modify models without proprietary software barriers and let implementing agencies conduct basic hydraulic checks without specialist consultants. And perhaps most importantly, they enable transparency in design assumptions that anyone can verify. Make data public, make models public.
For the Uganda project, we used epanet-js, an open-source web application from Canada that runs the EPANET engine directly in the browser. Built by just three developers, it offers a modern, user-friendly interface with GIS model building, network review tools, and fire flow analysis. Licensing is one-off and there’s no vendor lock-in. We used it for model validation and to check system behaviour under critical conditions: peak demand scenarios, low-flow situations, and pressure distributions across the network. All with GIS background and nice visualisations to pick up critical aspects very quickly if you know what you are looking for.
The business model of subscriptions has taken over so much software; no more paying for one licence for life and having updates for free. Now it’s subscriptions and maintenance fees. Sure, software development costs money, as does marketing and big bonuses for those at the top. But is this sustainable, especially with web cloud services and AI-supported development? Tools like epanet-js represent where engineering software could be heading: accessible, web-based, built on the same proven engines, without the overhead. Whether that future arrives depends on whether the industry supports it.
Open-source tools in engineering are nothing new, especially in academia, but they’re often heavily coded in Python or R or similar and require high-level skills to use. That’s no longer a good excuse.
With AI-backed coding, a user-friendly app or dashboard can be built in minutes.
The Water Supply Project will eventually provide clean water to 30,000 people. The hydraulic model that ensures the system works properly shouldn’t require more expensive software than the communities it serves could ever afford.
