Import and export
Open SWMM .inp files, build a project from survey schedules, DXF drawings or GIS layers, and export the model, SWMM's .rpt and .out files, CSV time series and DXF drawings.
Open and save SWMM files
- File > Open... (Ctrl+O) opens a SWMM 5 .inp file from your computer. Pick its rainfall or other data files at the same time and they are attached to it. Lines the file names without defining are listed in the Status Report until you run.
- File > Save (Ctrl+S) downloads the project as an .inp file named after the open file. If you set a coordinate system, it is saved as a comment line that SWMM ignores.
- Files are read in the browser and never uploaded.
Build a project from a survey
File > Import Survey..., Tools > Survey Import... or Import a survey... in the Start window opens the Survey Import window. Pick one or more files:
| Source | What it reads |
|---|---|
| Excel or CSV | A manhole schedule (MH No, Easting/Northing or Lat/Long, GL, IL or Depth of MH, Dia) and a pipe schedule (From MH, To MH, Dia (mm), Material, Length, U/S IL, D/S IL, Gradient 1 in), in one workbook or in two files picked together. |
| DXF drawing | Sewer polylines, manhole blocks, points or circles, and text labels such as MH-12, GL 101.25, IL 99.80 and 200 mm. |
| GeoJSON or zipped Shapefile | Sewer lines and manhole points, with their attributes. |
- Pick the files. DrainPilot detects which schedule is which and what each column means; correct any column in the lists. For a DXF, tick which layers hold sewers, manholes and labels; for GIS, which attribute is which.
- With a manhole schedule and no pipe schedule, choose Pipe schedule none: connect manholes and a Flow rule to join them: Nearest lower invert (the default), Nearest lower ground or Schedule row order, with a Max sewer length (m) (150 to start).
- Leave Infer missing inverts ticked to fill blank invert levels, with the Min cover (m) to keep (1 to start). Set the Default dia (mm) (200) and Default material (RCC) for pipes the source does not size.
- For a DXF set the Snap tolerance, Label radius and Drawing units (metres, millimetres or feet). For lat/long data choose Lat/long to: the UTM zone of the data, or a projected system.
- Read the preview: a plan with surveyed manholes, manholes with an inferred invert and outfalls marked; the counts of manholes, sewers, length and outfalls; any problems; and the Inference report.
- Type a Project name and press Create project. The new project replaces the open one, in LPS with dynamic wave routing.
- Inverts are filled walking downstream. Surveyed values are never changed. A gap between two known inverts is filled at a uniform gradient; with nothing known downstream a pipe falls at the CPHEEO minimum slope for its size, or deeper to keep minimum cover; a starting manhole sits at minimum cover; and crowns are matched where a larger sewer leaves a manhole. Every filled value is flagged in the inference report.
- Manning n comes from the pipe material (SM Table 3.11: 0.011 for RCC, 0.010 for HDPE or uPVC, 0.013 for unlined CI or DI); an unrecognised material gets 0.013.
- An outfall taking more than one sewer is kept as a junction draining through a 1 m stub to a new outfall named with _OUT, because SWMM allows an outfall one link.
Export results
File > Export Results is available after a run. Its items:
| Item | File |
|---|---|
| Status Report (.rpt) | SWMM's report of the run, as text, named after the project, for example indian-storm-catchment.rpt. |
| Binary Results (.out) | SWMM's binary output file, for other SWMM tools. |
| Time Series of Selected Object (.csv) | Every result variable of the selected node, link or subcatchment at every reporting period. Select the object first; the item then names it, for example Time Series of J1 (.csv). |
| System Time Series (.csv) | The system-wide results (rainfall, runoff, inflows, flooding, outflow, storage and so on) at every reporting period. |
The CSV files start with Date and Time columns, then one column per variable, and open in Excel. The compliance statements, the cost estimate and the 2D flood map have their own exports: CSV and Excel (Storm drain compliance, Sewer compliance), Excel and PDF (Cost estimate), and PNG, GeoJSON and CSV (Flood 2D).
Export CAD drawings (DXF)
File > Export CAD (DXF)... or Tools > CAD Export (DXF)... writes DXF R12 drawings that open in AutoCAD and other CAD programs.
- Plan. Choose the Scale (1:500 to start) and whether to write GL and IL at manholes, then press Download plan DXF. The plan carries the manholes and sewers with IDs, diameters, lengths, gradients and flow arrows, on layers named DP-PLAN-*.
- Longitudinal sections. Choose the Horizontal (1:1000) and Vertical (1:100) scales. The list starts with the longest path to an outfall; add paths with From, to and Add path, or Remove one. Press Download profiles DXF for one sheet per path.
- Each sheet has the ground, invert and crown lines, the manholes, and a data band of MH No, chainage, GL, IL, depth of cutting, diameter, gradient 1 in X and length. After a run it also draws the HGL, the highest head at each manhole over the run, and adds it to the band.
File > Print opens the browser's print dialog for the workspace as it is on screen.