Support
Questions, feedback, or a bug to report? We'd love to hear from you.
Frequently asked
Does HydroSewer work without internet?
Yes, for everything except the optional map background. Opening, editing, simulating and saving a model, and taking field notes and photos, need no connection. The map background shows Google Maps and needs a connection; without one, the network is shown without the map. HydroSewer has no account and no analytics of its own, and your models stay in local files on your device.
How do I put my network on the map?
Open ⋮ → Map background and turn on Show map (the first time, the app shows Google’s notice). Then tap Find your area on the map and tap your town: HydroSewer tries the coordinate systems it knows and, if one puts your network there, proposes it; nothing is applied until you tap Use. A .inp that declares a supported EPSG code in its [TITLE] (Q_VAR_PROJECTION=EPSG:<code>), like the Demo Village sample, is already placed when you open it. You can also set UTM yourself (zone and hemisphere), or, under Advanced, a Transverse Mercator grid (origin, false easting and northing, scale factor, units) or longitude/latitude, copied from your CAD or GIS. If your network is in local coordinates or HydroSewer does not know its grid, use Line up on map: tap a node, then its place on the map, 4–5 times. The preview is free; saving the alignment is part of HydroSewer Pro. The map background works on iPhone, iPad and Android.
The network lands in the wrong place on the map. What should I check?
Most often the units: SWMM files in feet read as meters, or the other way round. Find your area on the map tries meters, feet and US survey feet for you. Then the grid: zone and hemisphere for UTM, or every parameter for a Transverse Mercator grid. If the grid sits on an older datum (not WGS84-compatible), set its ellipsoid and 3-parameter shift under Advanced (datum), using the values from your GIS. HydroSewer warns when the network falls very far from the grid origin or spans more than 200 km.
Can I lay out a new network in the field?
Yes, as a preliminary layout. Open ⋮ → New network, then ⋮ → Map background → Use my location: the map centers where you are and the network gets UTM coordinates in meters for that zone. A dot shows your position as you walk. Add each manhole with the Create tools by tapping its place on the map; it gets the coordinates of that spot. Your location never places or moves anything; you do. The result depends on the map imagery and on where you tap: check positions and elevations before using it for design. It does not replace a survey.
Does HydroSewer use my location?
Only if you allow it, and only while you use the app: to center the map background, show where you are, and tag your field notes with where they were taken. It is read on your device, and HydroSewer never sends the reading to us, to Google or anyone else. When the map is centered on you, Google receives the map area around you. The map position and the “you are here” dot are never saved. A note’s position (latitude, longitude, accuracy and time) is saved in your .hydrosewer project and printed in the notes PDF, and leaves your device only if you share them. Turn it off in Field Notes → ⋮ → Tag notes with my location. See the privacy policy.
What does HydroSewer Pro include?
HydroSewer Pro is an optional one-time in-app purchase. It adds: exporting the network as a standard SWMM .inp file (field notes stay in the project), exporting node and link results to CSV with every time step, the field notes PDF report (with your logo, the photos and map links), and saving the map alignment made with Line up on map. Modeling, simulation, the map background and field notes are free.
What is in the field notes PDF report?
With HydroSewer Pro, Field Notes → the PDF icon → Share PDF builds a report you can send or print: your logo, company name and “Prepared by” at the top (set once in Field Notes → ⋮ → Report logo & company; kept on your device, never inside the project file), a summary and an index, then each element with a line of its model data and its notes with their photos. A note with a position shows where it was taken and a View on map link, which opens Google Maps only if the reader taps it. It holds your open notes; turn on Include resolved to add the resolved ones.
What files can I open?
HydroSewer imports EPA SWMM 5 .inp input files (and reads the coordinate system a file declares with Q_VAR_PROJECTION=EPSG:<code> in [TITLE], for supported codes) and opens and saves native .hydrosewer project files, with Save project and Save as in the menu. With HydroSewer Pro it also exports a standard SWMM .inp and results as CSV.
Does it run the real SWMM engine?
Yes. HydroSewer runs the actual EPA SWMM 5 computational engine on-device, in a background isolate so the interface stays responsive.
Which platforms are supported?
HydroSewer runs on iPhone, iPad and Android phones and tablets. It also runs on Apple silicon Macs.
Can I rely on the results for design?
Results are produced by the EPA SWMM 5 engine and must be reviewed and verified by a qualified, responsible engineer before being used for any design, construction, or permitting. HydroSewer does not replace professional engineering judgment.