Projects

A project holds the whole model you work on: the network, its operational data, its zones and customer points, and its simulation settings. The app keeps all of it in one .ejsdb file on your own disk. This is the format the app reads and writes. An EPANET .inp file is an exchange format here. You import one to bring a model in, and you export one to hand it on. See Import and export.

Nothing leaves your machine. The file picker is the browser’s own, and the file goes where you put it. Between saves, the work sits in browser storage on the machine you use. See Storage and recovery for what that means, and for what it does not survive.

This page covers the three file jobs that are common to all three ways of working: starting a project, opening one, and saving.

The File menu

The folder icon at the left of the toolbar opens everything on this page:

Entry	What it does
New project	A submenu: Blank project, From GIS data, From EPANET INP
Open	One picker for both .ejsdb and .inp
Save	Writes the project file
Save as…	Writes it somewhere new
Import	Customer points, zones
Export	EPANET INP, Asset data, Simulation results
Recent	Files you opened or saved here before

Import and Export have pages of their own. See Customer points, Zones and Import and export. From GIS data opens the model builder. See Build a model from GIS.

Starting a blank project

Three commands start a blank project: File > New project > Blank project, Alt+N, and Start project on the welcome dialog. All three open New project. This dialog asks five things and then makes an empty model.

The first question is how the network is positioned, and you answer it with a pair of cards:

• Map-based puts the network on a real map in longitude and latitude. This is the choice for anything that exists on the ground. The app fetches elevations from the terrain service as you draw. See Elevations.
• Simple X-Y Grid is a local coordinate system. It has no background map and no real-world position. This card suits a test network, a textbook example or a schematic. A grid project has no terrain, so the app does not fetch elevations. The location search is disabled too.

The map behind the dialog shows a preview as you switch between the two cards. You can change the choice afterwards. See Projections.

Location takes a place name. When the project opens, the app centers the map on that place. The field reads Search for a location…, and it searches place names, not coordinates. The field is optional. If you leave it empty, you get whatever the map was showing.

The last three questions set the units and the hydraulics of the project: Flow units, Pressure units and Headloss formula. A new project starts at liters per second, the pressure unit that goes with it, and Hazen-Williams. A change to Flow units resets Pressure units to the default for that system, so set the flow unit first. All three are fixed for the life of the project, and the simulation settings dialog shows them read-only. They are worth getting right here.

Create builds the project and moves the map. Cancel puts the map back where it was.

Note

A new project has no file name yet, so the menu bar shows nothing beside the logo until the first save. Save suggests my-project.ejsdb.

A new project replaces what is open. If the current project has unsaved changes, the app asks you first. See Unsaved changes.

Opening a project

File > Open, or Ctrl+O, opens one picker. The picker accepts both .ejsdb and .inp. Open model on the welcome dialog runs the same command. You can also drag a file from your file manager onto the map. There is no separate entry for opening an INP. See Bring in an existing model for what an INP import asks you on the way in.

A project file opens directly. A progress dialog counts through the stages: Opening project file…, Reading assets…, Reading customer points…, Reading settings…, Building model…, and Finalizing…. The map then fits itself to the extent of the network, and a Project opened notice appears. The file carries the model exactly as it was saved, so there is nothing to answer and nothing to make sure of afterwards.

Three problems can stop the open, and each one has its own notice:

• A file written by a newer version of the app than the one you run.
• A file that the app cannot read as a project at all.
• A project whose format the app cannot upgrade to this version.

All three notices name the file version and the app version. If you report one, quote both.

If you pick a file that is neither .ejsdb nor .inp, Failed to open model appears. It gives See demo networks as a way back to the welcome dialog.

Recent files

File > Recent lists the last ten files you opened or saved here, most recent first. An icon shows whether an entry is a project or an INP. If you choose an entry, the file reopens in place, without a picker.

The welcome dialog shows the same list as cards under Recent projects. Each card has a thumbnail of the network as it was when the app wrote the entry. The two demo networks sit alongside them. If you have no recent files, the dialog shows Demo networks instead.

Caution

Recent depends on the File System Access API. At the time of writing, only Chromium browsers have it. In Firefox and Safari, the submenu does not appear, and the welcome dialog never shows Recent projects. Everything else on this page works, but every open starts at the picker.

The list holds a handle to the file rather than a copy of it, so:

• A reopen asks the browser for permission again. If you refuse, you get Permission to access this file was denied. Try opening again.
• A file that was moved, renamed or deleted gives The file could no longer be found. It may have been moved, renamed, or deleted. The app then drops the entry from the list.
• Any other problem gives Could not open the recent file. Try Open model option. The app drops that entry too.

The app never adds a demo network to the list. If you open a demo network and save it, the app adds the file you saved.

Saving

Save writes the project. You can press the toolbar button, choose File > Save, or press Ctrl+S.

The first save in a project opens Your work is now saved as a Project. This dialog explains that the file is the app’s own format. It also explains that File > Export still produces an INP whenever you want one. To hide the dialog in future, tick Don’t show this again. Press Got it, and the file picker follows.

The suggested name is the name of the project, if the project has one. If the model came from an INP, the suggested name is the INP name with the extension swapped. Otherwise the app suggests my-project.ejsdb. The name you give the file becomes the project name in the menu bar.

Later saves write straight to the same file, with no picker and no dialog. A toast reads Saving project… and then Saved.

Save as…, or Ctrl+Shift+S, always asks for a location. The file you choose becomes the file that later saves write to.

These problems can stop a save:

• If you dismiss the picker, you get Canceled saving and nothing is written.
• If you lose write permission on the file, you get Permission to write the file was denied. The project was not saved.
• Any other problem gives Couldn’t save project.

In a browser without the File System Access API, the save arrives as a download instead. The app gets no handle to what it wrote, so it goes on treating the project as unsaved. The dot stays, and the app makes no Recent entry. The next Save downloads another copy rather than overwriting the first.

Unsaved changes

While there are changes that are not in the file, the menu bar shows a dot beside the file name of the project. A project that you never saved always shows the dot.

A command that replaces what is open looks for unsaved changes first. New project, Open and a Recent entry all do. If there are changes, Unsaved changes asks whether to save the changes you made to the current project:

• Save and continue saves the project and then carries on. If the save is canceled or fails, the dialog stays and nothing is replaced.
• Discard changes goes ahead and loses them.
• Cancel stops.

If you close the browser tab with unsaved changes, the browser shows its own “leave site?” prompt. The prompt belongs to the browser, not to the app. Its wording and its buttons are the ones your browser uses.

Caution

A save is the only thing that puts your work somewhere it survives a cleared browser. Save early in a session rather than at the end of it. See Storage and recovery.

What the project file holds

The file holds everything the app models. This includes what an INP has no place for: customer points and their demands, custom attributes, zones, the pipe and pump libraries, native pump controls, and the projection of the network.

The file does not hold anything that is a view of the model rather than the model itself:

• Symbology (the color rules, breaks, labels and node sizes) and the custom layers on the Map tab. Both live in the browser tab and are gone after a reload. Two people who open the same file see the same network with no coloring on it. See Symbology and The map and its layers.
• Where the map was pointing and how far in it was zoomed.
• Simulation results. A reopened project starts again at Ready to run, and a second run reproduces the results.
• Scenarios. They live in the session only and are gone when you close the app. See Scenario work.

The file also carries no language setting. The same project opens the same way in every interface language. See Languages.

Next

• Import and export — getting an INP, asset data or results out.
• Bring in an existing model — what an INP import asks you, and what to check after it.
• Storage and recovery — where the work lives between saves.
• Projections — changing the coordinate system a project was started in.
• Keyboard shortcuts — the file shortcuts in one place.