Opening an existing project

You can open your existing EPANET models into epanet-js using the standard INP file format. This lets you view, edit, and run simulations right in your browser –no extra software needed.

You can access this option from the Welcome modal or from the Create new… dropdown in the main toolbar.

Click Open INP and select an .inp file.
The network loads onto the map

Tips for a successful import

1. Nodes must have coordinates

All nodes (junctions, reservoirs, tanks) defined in your INP file must have corresponding entries in the [COORDINATES] section to be properly imported and visualized. If coordinates are missing for some nodes, you will receive a warning, and those nodes will not be included in the imported model.

2. Import issues & warnings

<aside> 💡

We're actively developing epanet-js to enhance INP file support and add more features. You can follow progress in our changelog and roadmap.

</aside>

When you import an INP file, epanet-js checks its contents. If it finds sections that aren't supported (e.g. options that differ from the default settings or water quality) it will list them as issues.

These issues appear in a dialog after the import finishes.
They're there to help you understand which parts of your model might not be fully supported or used in epanet-js.
It's a good idea to review them so you’re aware of any differences between your original EPANET model and what’s shown in epanet-js.

When you save the model, epanet-js will ask you to save a copy so your original file stays unchanged.

INP support details

Here's a breakdown of how epanet-js currently handles different sections commonly found in an EPANET INP file:

Section	Support Level	Details & Limitations
Nodes & Links
`[JUNCTIONS]`	Fully supported
`[RESERVOIRS]`	Fully supported
`[TANKS]`	Fully supported
`[PIPES]`	Fully supported
`[PUMPS]`	Fully supported
`[VALVES]`	Fully supported	Supported types include FCV, PRV, PSV, PBV, TCV, GPV and PCV.
Operational Data
`[DEMANDS]`	Fully supported
`[STATUS]`	Fully supported
`[EMITTERS]`	Fully supported
`[PATTERNS]`	Fully supported
`[CURVES]`	Fully supported
`[CONTROLS]`	Fully supported
`[RULES]`	Fully supported
Options & Settings
`[REPORT]`	Fully supported
`[OPTIONS]`	Fully supported	Supported options: `UNITS`, `PRESSURE`, `BACKFLOW ALLOWED`, `HEADLOSS`, `VISCOSITY`, `SPECIFIC GRAVITY`, `TRIALS`, `ACCURACY`, `FLOWCHANGE`, `HEADERROR`, `CHECKFREQ`, `MAXCHECK`, `DAMPLIMIT`, `UNBALANCED`, `DEMAND MODEL`, `MINIMUM PRESSURE`, `REQUIRED PRESSURE`, `PRESSURE EXPONENT`, `PATTERN`, `DEMAND MULTIPLIER`, `EMITTER EXPONENT`, `QUALITY`, `DIFFUSIVITY`, `TOLERANCE`
`[TIMES]`	Fully supported
`[ENERGY]`	Fully supported
`[QUALITY]`	Fully supported
`[REACTIONS]`	Fully supported
`[SOURCES]`	Fully supported
`[MIXING]`	Fully supported
Geographic Data
`[COORDINATES]`	Fully supported	Nodes without valid coordinates will cause warnings and will be omitted.
`[VERTICES]`	Fully supported	Pipe/link vertices with invalid coordinates will cause warnings and will be omitted, affecting link shapes.
Ignored Sections
`[TITLE]`	Ignored	This section is not currently used.
`[BACKDROP]`	Ignored	Backdrop image information is not used.
Unsupported Sections
`[LABELS]`	Not supported	Map labels and their coordinates are not imported. An issue will be flagged.
`[LEAKAGE]`	Not supported	Individual pipes leakage parameters are not imported. An issue will be flagged.
`[TAGS]`	Not supported	Link/Node category tags are not imported. An issue will be flagged.