StormSewer keeps a small preferences file per user:
%APPDATA%\StormSewer\app_prefs.json on Windows,
~/Library/Application Support/StormSewer/app_prefs.json on
macOS, $XDG_CONFIG_HOME/stormsewer/app_prefs.json (or
~/.config/stormsewer/) on Linux. It is JSON with defaults
for every key, so deleting it resets everything and an older file still
loads. Nothing about a model is stored in it.
| Setting | Where you set it | Key |
|---|---|---|
| Theme — Dark, Light, or the system's | View → Dark theme / Light theme | theme |
| SWMM layer settings — per-kind visibility, labels, symbol size and colour, arrows, grid, underlay opacity, results overlay | Layers tab (chapter 7) | swmm_layers |
| Snap grid spacing for the storm-sewer plan | storm-sewer workspace | snap_grid_ft |
| Analyse automatically after an edit (storm-sewer workspace) | storm-sewer workspace | auto_analyze |
| Show the quick-start on launch; the interactive tutorial's "Don't show on startup" | Help → Interactive Tutorial | show_quick_start, tutorial_done |
| Draw zero-area catchments (storm-sewer workspace) | storm-sewer workspace | draw_zero_area |
| The support reminder's opt-out and last-shown time | the reminder | coffee_optout, coffee_last_epoch |
The SWMM workspace's grid-snap spacing, object snap and the View-menu toggles (labels, arrows, grid) are per session and start from their defaults each launch; the Layers tab's copies of arrows and grid are the persisted ones.
Beside it: recent.json (storm-sewer projects) and
recent-inp.json (SWMM models), eight entries each, most
recent first.
| Variable | Effect |
|---|---|
STORMSEWER_SWMM_ENGINE_DIR |
A folder searched first for runswmm (§1.2). |
STORMSEWER_ALR_SCRIPT,
STORMSEWER_ALR_PYTHON |
Where ALR's run_headless_swmm.py is, and which
interpreter runs it (§9.5). |
STORMSEWER_SOFTWARE_GL=1 |
Windows: skip the hardware renderers and start on the bundled Mesa software OpenGL. |
StormSewer [file] open a .inp, .ssproj, .stm, .xml (LandXML) or .dxf
StormSewer --check-renderer start, draw one frame, report the renderer, exit
StormSewer --version
StormSewer --helpA .inp opens in the SWMM workspace; the others open in
the storm-sewer workspace.