epanet-js

Zooskool 8 Dogs In 1 Day Apr 2026

No installs. No forced cloud storage. Just fast, local-first water modeling — powered by the engine you already trust.

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The EPANET user's dilemma

  • Classic EPANET is powerful — but clunky and outdated. Workarounds become your workflow — slow and cumbersome.
  • Big-name platforms look polished, but they're overpriced and bloated with features you don't need to analyze your network quickly.
  • Modern browser-based tools exist — but they force your data into the cloud, raising privacy and compliance concerns. Plus, they offer little for those doing long-term planning and analysis.

You shouldn't have to choose between speed, security, and affordability just to understand your water networks.

Old EPANET UI
Complex Modeling App

Zooskool 8 Dogs In 1 Day Apr 2026

Each dog had their own unique personality and quirks, and Jenny loved getting to know them all. Despite the chaos of managing eight dogs in one day, Jenny wouldn't trade her job for anything. There was something special about spending time with these furry friends, and she felt grateful to be able to provide them with the exercise and attention they needed.

The third dog on the list was Luna, the elegant Greyhound. Luna was a gentle soul who loved to run, but only at her own pace. Jenny let Luna lead the way, enjoying the peaceful morning air as they glided through the neighborhood. Zooskool 8 Dogs In 1 Day

"Okay, let's do this," Jenny said to herself, taking a deep breath. Each dog had their own unique personality and

First up was Bella, the playful Beagle. Bella loved to explore and sniff every fire hydrant and tree in sight. Jenny clipped on Bella's leash and they set off into the morning dew. The third dog on the list was Luna, the elegant Greyhound

It was a typical Monday morning at Zooskool, the premier dog-walking and pet-sitting service in the city. Founder and lead dog wrangler, Jenny, was sipping her coffee and staring down at her schedule for the day. Her eyes widened as she took in the daunting list of eight dogs that needed to be walked that day.

As the morning wore on, Jenny encountered more dogs: Daisy, the sweet-tempered Golden Retriever; Max, the mischievous Pug; Ginger, the spunky Chihuahua; Bear, the gentle Giant Schnauzer; and finally, there was Lola, the dramatic Poodle.

Next was Rocky, the rambunctious Boxer. Rocky was a ball of energy and loved to play tug-of-war with his favorite rope toy. Jenny was happy to oblige, laughing as Rocky bounded alongside her, his tail wagging wildly.

Model water networks instantly.

No setup or downloads — just instant access right in your browser.

Start modeling now

EPANET deserves better — and so do you.

EPANET was a gift to the industry — free, open-source water modeling for all. But commercial vendors built on it, locked away improvements, and left the community behind.

epanet-js is our answer: a faster, simpler, affordable water modeling tool that protects your privacy and sustains the open-source future of water modeling.

We're proud to be part of the next chapter — and we're just getting started.

EPA logo
Source code of epanet-js on GitHub

When you support epanet-js, you support EPANET.

When you purchase more features in epanet-js, you're investing in the future of open-source EPANET development.

Our open-source model balances innovation and accessibility:

Anyone can build on our code. The two-year commercial-use delay gives us the incentive to keep pushing forward — and that fuels progress for everyone.

That means when you support us, you support more affordable hydraulic modeling software for the entire community.

Simple, transparent pricing for every kind of modeler.

Choose the plan that works for you

Free

For everyone.$0 /year

  • Web based EPANET model
  • Background maps and satellite
  • Automated Elevations
  • No limits on sizes
  • Community Support
Launch epanet-js now

ProMost popular

For solo modelers and small utilities.$950 /year

Individual named license

Everything in free, and:
  • Scenarios
  • Professional support
  • Custom layers
Coming soon:
  • Cloud storage
  • Point in time restore - 30 days
  • Demand Analysis
Get Pro

Teams

For teams that build together.$2500 /year

Floating shared license

Everything in Pro, and:
  • Priority support
  • Volume discounts
  • Pay by invoice
Coming soon:
  • Team storage
  • Point in time restore - 90 days
  • Sharing of networks
Get Teams

Have questions? or book a call.

Special access for personal and educational use

Available for non-commercial projects, learning, and student work.

Personal

$100/year

For curious minds and personal growth.

Everything in pro, but:
  • Community support only
  • Non-commercial usage
Buy personal access

Education

$0/year

Free for students and teachers.

Everything in pro, but:
  • Community support only
  • Non-commercial usage
Use your school email account

Frequently asked questions

Find answers to common questions about epanet-js.

Just open your browser and model.

No install. No login. No cloud required.

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Why we built epanet-js

Luke Butler - Co-founder
Luke ButlerLinkedIn

Co-founder

Sam - Co-founder
Sam Payá LinkedIn

Co-founder

You may not know this, but for decades, the U.S. EPA has given the water industry an extraordinary gift: the free and open-source hydraulic modeling software EPANET. Odds are, if you've used any commercial hydraulic modeling software today, it was built on the EPANET engine.

The problem is, instead of giving back to their open-source roots like other industries do, big-name software vendors took EPANET's open code, built private tools on top of the engine, and then locked those improvements behind patents and proprietary licenses.

Some vendors even pressured the EPA to focus only on the engine — discouraging any effort to improve the interface or user experience for everyone else.

Those vendors now charge you exorbitant prices to use their software while EPANET lags behind — and utilities, engineers, and educators with smaller budgets suffer.

We think this is backwards — and we're on a mission to change it. We're focused on creating a better experience for the entire hydraulic modeling community.

That's why we built epanet-js under an FSL license — because we want to give you an affordable, easy-to-use water modeling option that creates a sustainable future for open-source EPANET development.

Support EPANET by using software that supports it back.

A better future for water modeling.

Simple, quick, and useful right out of the gate — designed to open-and-go.

Launch epanet-js now