Does an engine route a sewer network the same way as SWMM 5.2.4?
Every engine runs this EPA SWMM 5 input file unchanged. Open it in EPA SWMM 5, or in any engine that reads the format, and you are running exactly what was scored.
On the map: click any element to see its line in the file and every engine's result there over time, or colour the network by how far each engine is from the reference.
The classic EXTRAN example: a branching sewer with surcharge and three inflow hydrographs, routed for 8 hours.
SWMM results are used for permits and designs; a different engine must reproduce them.
In rank order: by each model's percent difference from the right answer, the largest over the test's accuracy checks (lower is better; results within 10 % of each other share a rank). Mass error, timing and NSE are shown beside it, not folded in. Each model runs the same inputs.
| Rank | Model | Difference | Largest difference in | Run time |
|---|---|---|---|---|
| 1= | SWMM 5.1.15 previous release | <0.01 % | Peak depths | – |
| 1= | OpenSWMM 6 vs SWMM 5.2.4 | <0.01 % | Peak depths | – |
| 3 | Hydra urban drainage | 4.5 % | Volumes | – |
| 4 | OpenSWMM 6 finite volume | 88 % | Peak depths | – |
Settings: swmm5 (swmm-toolkit 0.10.0)
Scored with method 3.0 · Score card: EPA SWMM 5.1.15
The badge always shows the latest published result.
Settings: openswmm (v6 engine, SWMM binary output)
Scored with method 3.0 · Score card: OpenSWMM Engine 6.0.0a4.dev1
The badge always shows the latest published result.
Settings: hydra CLI 4.1.1 (uds engine, SWMM-format binary output)
Scored with method 3.0 · Score card: Hydra 17.0.0 urban drainage
The badge always shows the latest published result.
Settings: openswmm (v6 engine, FLOW_ROUTING FV, SWMM binary output)
Scored with method 3.0 · Score card: OpenSWMM Engine v6 finite volume (6.0.0a4.dev1)
The badge always shows the latest published result.
Candidate. To become frozen it needs: maintainer review recorded.
| Check | Difference measured as a percentage of | Latest | Difference | Why this check |
|---|---|---|---|---|
| peak_depth relative_peak of h · in the score | already a percentage | – | Peak depth within ±1 % of SWMM 5.2.4 at every node. | |
| volume relative_volume of Q · in the score | already a percentage | – | Conveyed volume within ±1 % of SWMM 5.2.4 in every link. |
Second build of the reference. The official EPA SWMM 5.2.4 official win64 binaries, run on this input and scored against the reference: pass (Peak depths 0 %; Volumes 0 %). Both builds agree, so the reference does not depend on the compiler.
SWMM 5.2.4, run on the test's own input.
Only frozen tests have fixed inputs and answers. This list is computed from the manifest and the published score cards; the rules are in the method.
| File | Role | Format | SHA-256 | Get it |
|---|---|---|---|---|
inputs/network.inp | network | inp | 739391331b14… | Download |
The first example of the EXTRAN user's manual (Roesner, Aldrich and Dickinson, 1988), as carried in the OWA/EPA SWMM 5 regression models: a dendritic sewer network with surcharge, driven by three inflow hydrographs and routed by dynamic wave for 8 hours.
The reference is EPA SWMM 5.2.4 (swmm-toolkit build; the official Windows binaries are checked against it in CI). A candidate passes when
every node's peak depth and every link's conveyed volume are within 1 % of the reference.
Source: HydroCouple openswmm.engine.benchmarks, owa-extran/extran1, commit 63eb8bc5b4e741c82195ed65c4d7d146b86da1cc. Regenerate the reference with
python scripts/make_reference.py B-EXTRAN-001.
A Track B fail shows a difference from SWMM 5.2.4, not a physics error.
Test B-EXTRAN-001_extran_parity · version 2.0.0 · data licence Unlicense