For drainage and stormwater engineers
DrainPilot: EPA SWMM storm drain and sewer modelling in your browser
See which streets flood in the design storm, and the drains that cause it.
DrainPilot runs the EPA SWMM 5.2.4 engine in a web browser. It opens and saves SWMM .inp files and adds 2D surface flooding, design checks, sewer auto-design and cost estimates.
DrainPilot Pro is $79 a month or $790 a year per person. Paid plans only.
- Engine
- EPA SWMM 5.2.4
- Files
- SWMM .inp, in and out
- Flooding
- 1D network plus 2D surface
- Install
- None. It runs in the browser
What you can do in DrainPilot
Each card is a guide in the DrainPilot documentation.
Getting started
Open a sample storm drain model, run it on the EPA SWMM 5.2.4 engine, read the results and save your work, in about five minutes.
Read the guideThe workspace
The menus, toolbar, Project Browser, Study Area Map, Property Editor, status bar and child windows, laid out like EPA SWMM 5.2.
Read the guideBuilding a network
Start a project, draw rain gages, subcatchments, junctions, outfalls, storage units, conduits, pumps and flow regulators, and set their properties.
Read the guideRainfall and design storms
Give subcatchments rain: rain gages, rainfall time series and data files, and a design storm built from your city's IDF curve by the alternating block method.
Read the guideRunning a simulation
Set the simulation options, attach rainfall and other data files, run SWMM with progress and cancel, and read the status report and continuity errors.
Read the guideViewing results
Colour the map by any result, step and animate through the run, plot time series and the profile of a sewer, query the map, and find SWMM's summary tables.
Read the guideFrom the blog
Methods and file formats behind DrainPilot, written up in full.
Design Storms in EPA SWMM: SCS Type II and Alternating Block
How to turn an NRCS Type II distribution or an IDF curve into a SWMM rain gage and time series, with the unit and timing rules that catch people out.
Tutorial1D-2D Flood Modelling in SWMM: Mesh, Coupling and Hazard
How a 2D surface mesh of junctions and wide open conduits couples to a SWMM sewer, how to build it from a DEM, size the cells and read flood depth and hazard.
TutorialHow to Calibrate an EPA SWMM Model Against Flow Data
Which SWMM parameters to adjust and in what order, how to read NSE, RMSE, peak, volume and timing errors, and the published targets a calibration should meet.
TutorialLID Controls in EPA SWMM: Modelling Green Infrastructure
The eight SWMM LID types and their layers, how LID units are placed in subcatchments, and how to read the LID Performance Summary in the status report.
TutorialShapefile to SWMM: Build a Model from GIS or CAD Data
Turn a shapefile, DXF drawing or manhole schedule into an EPA SWMM .inp file: the attributes you need, how inverts become offsets, and the errors to expect.
GuideHow to Run EPANET and EPA SWMM on a Mac, Linux or Chromebook
The EPA desktop programs for EPANET and SWMM install only on Windows. Five ways to run them on a Mac, Linux PC or Chromebook, and which one suits you.