A Windows desktop utility for preprocessing and editing EPA SWMM input files, with a focus on time-step recommendation, discretization review, and artificial spatial discretization of conduits through insertion of dummy nodes. The repository is a public fork of ecotecnologias/ReSWMM, and the visible project page shows that it distributes both source code and a compiled executable together with English and Portuguese manuals.[1]
ReSWMM is not a replacement for SWMM's hydraulic solver. Instead, it appears to be a specialized support tool that helps users inspect a SWMM input file, assess whether additional discretization may be warranted, recommend a routing time step, and automatically modify the network representation when artificial spatial discretization is desired.[1]
The repository's GitHub description states that the software can read and edit a SWMM input file, recommend the time step based on EXTRAN recommendations and Vasconcelos et al. (2018), create artificial spatial discretization by placing dummy nodes between actual nodes, and analyze the input file to determine whether discretization is required.[1] That positions the tool squarely in the part of SWMM practice concerned with numerical stability, representation of rapidly varying flows, and control of discretization effects.[2][3][4]
In SWMM dynamic-wave modeling, routing time step and conduit discretization can strongly affect numerical behavior, stability, and how well rapid hydraulic changes are represented. Public discussions of SWMM time-step selection emphasize that the routing time step should be smaller than the shortest time for a wave to traverse a conduit, and public explanations of conduit lengthening note that SWMM already uses a CFL-style criterion to adjust short conduits when explicit time-step criteria are exceeded.[4][5]
ReSWMM appears to address that modeling challenge by doing two things outside the core SWMM engine: first, it evaluates an existing input file to flag cases where discretization may be advisable; second, it can automatically insert dummy nodes to create a finer spatial representation before the model is run.[1] This makes the repository especially relevant for users dealing with short conduits, rapid transients, mixed-flow conditions, or networks where numerical representation is sensitive to link spacing and time step.[2][6][7][8]
The repository is compact but includes both code and end-user materials.[1]
| Item | Description |
|---|---|
ReSWMM/ |
Main application source folder for the desktop tool.[1] |
ReSWMM.exe |
Precompiled Windows executable distributed directly in the repository.[1] |
ReSWMM Manual_EN_2.pdf |
English user manual for the application.[1] |
ReSWMM Manual_PT_2.pdf |
Portuguese user manual for the application.[1] |
.gitignore |
Standard repository ignore file.[1] |
GitHub reports the codebase as 100% Visual Basic .NET, which indicates the application is a .NET desktop utility rather than a C/C++ extension to SWMM itself.[1]
Based on the repository page, ReSWMM offers four main functions:[1]
- Read and edit SWMM input files — the software can open and modify SWMM
.inpmodel files.[1] - Recommend a time step — the recommendation is based on EXTRAN guidance and Vasconcelos et al. (2018).[1]
- Create artificial spatial discretization — dummy nodes are inserted between actual nodes to subdivide conduits.[1]
- Analyze whether discretization is needed — the input file is evaluated to determine whether discretization is required.[1]
Those capabilities line up with known areas of SWMM numerical practice. Public references note the importance of time-step sensitivity analysis, especially for peak-flow timing and continuity behavior, and published discussions have examined discretized model setups and transient-flow representation in SWMM.[2][9][7][8]
Artificial spatial discretization is a common strategy when a model needs more internal computational points along a conduit than are present in the original network abstraction. In practice, this can help when users want finer representation of hydraulic gradients, pressurization behavior, or rapidly varying flow features than a coarse link-node layout can provide.[2][7][8]
This differs from SWMM's built-in conduit lengthening approach. Public explanations of conduit lengthening show that SWMM can increase short conduit lengths internally to satisfy a time-step criterion while adjusting slope and roughness to preserve full-flow hydraulics, whereas ReSWMM appears to explicitly modify the input-file geometry by inserting intermediate dummy nodes.[4]
Although the repository page does not include a README, the visible description and file contents suggest a practical workflow like this:[1]
- Start with an existing SWMM
.inpfile.[1][10] - Open it in ReSWMM and run the internal analysis to identify conduits or model areas where discretization may be advisable.[1]
- Review the recommended routing time step based on the implemented criteria.[1]
- Apply artificial discretization, which inserts dummy nodes between actual nodes where needed.[1]
- Save the modified input file and run the revised model in SWMM for comparison and sensitivity testing.[1][9]
That kind of preprocessing workflow can be especially helpful when investigating model sensitivity to routing resolution, short links, or rapidly varying hydraulic conditions.[3][6][8]
The GitHub page shows that this is a public fork of ecotecnologias/ReSWMM and that the current branch is up to date with upstream master.[1] The visible metadata shows 14 commits, 1 branch, 0 tags, no releases, and no published packages.[1]
The latest visible commit is about five years old, and the repository includes a compiled executable committed directly into source control.[1] That suggests the project is better viewed as a preserved, ready-to-download research utility than as a currently release-managed software product.[1]
A stronger README for this repository should explain:
- Which versions of SWMM input files are supported.[1][10]
- Whether the tool edits geometry only or also modifies SWMM options and routing parameters.[1]
- How the time-step recommendation is computed in practice, beyond the citation to EXTRAN and Vasconcelos et al. (2018).[1]
- How dummy nodes are inserted and how conduit properties are redistributed after discretization.[1]
- Whether the output is written as a new
.inpfile or overwrites the original file.[1] - Any limitations around pumps, regulators, irregular shapes, or special hydraulic structures; one visible commit message mentions support for irregular shapes under interval-fixed discretization.[1]
Below is a more complete GitHub-facing README draft that could replace the missing repository README:
ReSWMM is a Windows desktop tool for reading, editing, and preprocessing EPA SWMM input files. It focuses on two practical numerical-modeling tasks: recommending an appropriate routing time step and creating artificial spatial discretization by inserting dummy nodes between existing SWMM nodes.[1]
The tool is intended to help SWMM users evaluate whether a model may benefit from additional conduit discretization and to automate input-file edits needed to create a finer spatial representation. It is especially relevant when working with short conduits, rapidly varying flows, or other situations where numerical sensitivity to time step and link spacing may affect results.[1][2][4][8]
- Read and edit SWMM input files.[1]
- Recommend a routing time step based on EXTRAN guidance and Vasconcelos et al. (2018).[1]
- Analyze a model to determine whether discretization is advisable.[1]
- Insert dummy nodes between existing nodes to create artificial conduit discretization.[1]
- Provide documentation in both English and Portuguese through the included manuals.[1]
ReSWMM/— Visual Basic .NET source code for the application.[1]ReSWMM.exe— prebuilt Windows executable.[1]ReSWMM Manual_EN_2.pdf— English manual.[1]ReSWMM Manual_PT_2.pdf— Portuguese manual.[1]
Dynamic-wave SWMM results can be sensitive to routing time step and link representation, especially in systems with short conduits or rapidly varying hydraulic conditions. Public SWMM guidance and related literature emphasize the need to examine time-step sensitivity and discretization effects rather than relying on a single default setup.[9][4][5][8]
ReSWMM supports that workflow by helping users inspect and modify the input model before running SWMM itself. It complements the core SWMM engine rather than replacing it.[1][10]
- This repository appears to target Windows users because it includes a
.exedesktop application and is written in Visual Basic .NET.[1] - The repository is a public fork of
ecotecnologias/ReSWMMand is currently shown as up to date with the upstreammasterbranch.[1] - The project includes manuals but currently has no root
README.md, no tags, and no formal GitHub releases.[1]
The repository would be easier to reuse with explicit instructions covering installation, supported SWMM versions, output-file behavior, and a worked example showing an input file before and after discretization. A short section explaining how the internal time-step recommendation is computed would also make the tool more transparent for advanced SWMM users.[1]