A Reference Hub for EPA SWMM5 and ICM InfoWorks Modeling
EPA SWMM5 is the open-source Storm Water Management Model at the core of urban drainage, sewer, and stormwater simulation worldwide — the engine inside InfoWorks ICM (optional), InfoDrainage, InfoSWMM, PCSWMM, and XPSWMM. Its future is being written now through SWMM5+ and Caleb Buahin's OpenSWMM, the open work pointing toward a true next-generation engine.
Fifty years with the engine, from punch cards to cloud, now turned toward what comes next: interactive SWMM tools, Ruby automation for ICM and InfoDrainage, AEC Collection workflows, and the road to SWMM6.
Who This Site Is For
🏛️ Municipal & Consulting Engineers
Calibrating real collection systems, running design storms, reviewing drainage plans.
🎓 Students & Researchers
Learning hydraulic modeling fundamentals and the numerics behind the engine.
🤖 ICM Power Users
Automating repetitive workflows with Ruby scripting inside InfoWorks ICM.
🔬 SWMM5 Developers
Validating engine behavior, testing edge cases, contributing to SWMM5+.
Why Modelers Use This Site
Searchable archive of real-world SWMM5 and ICM issues with documented fixes.
Ruby scripts for batch imports, network validation, and custom reporting.
"Inside SWMM5" posts explain what the numerical solver is actually doing.
Guidance for moving between EPA SWMM5, InfoSWMM, InfoSewer, PCSWMM, XPSWMM, and ICM.
🚀 The Road to SWMM6
SWMM5 is not the end of the line. Three parallel efforts are shaping the next engine, and this site tracks all of them release by release. I chair the SWMM5+ Technical Advisory Committee and serve on the EPA SWMM TAC, so the coverage here comes from inside the process, not from press releases.
🧪 EPA SWMM 6.0 Alpha & SWMM2D
The first 6.0.0 alpha builds pair the engine with the SWMM2D overland flow solver. Coverage here walks each release: what changed, what broke, and what it means for your existing INP files.
⚙️ SWMM5+ at CIMM
The Center for Infrastructure Modeling and Management (CIMM.org) is rebuilding the hydraulics solver as a parallel, finite-volume engine. TAC updates and test results land here first.
🌊 OpenSWMM & the Open Lineage
Caleb Buahin's open development work points toward component-based, coupled modeling. Understanding this lineage now means fewer surprises when your tools adopt it later.
Not sure where your SWMM5 features land in the next generation? The
SWMM6 Interop Atlas
maps the transition, section by section.
Featured SWMM Apps & Utilities
Free, browser-based tools for EPA SWMM5 and ICM workflows. Single-file apps, vibe coded with Claude. No install, no login, no data leaves your browser.
SWMM5 Report File Reader
Generate 3,000+ informative charts and tables from any SWMM5 RPT file. Visualize continuity errors, flow summaries, node flooding, and conduit performance in seconds.
INP File Visualizer
Upload any SWMM5 INP file and instantly view network statistics and interactive diagrams.
ICM Ruby Script Library
150+ ready-to-use Ruby scripts for ICM InfoWorks automation, from batch imports to network cleanup.
InfoSewer → ICM Converter
Step-by-step guidance and tools for migrating InfoSewer models to ICM InfoWorks.
SWMM5 Runoff Engine Explorer
Watch the runoff engine take a timestep. A Cash-Karp RK5 solver drives the nonlinear reservoir, and every slider maps to the real equation in runoff.c.
ReSWMM CFL Analyzer
See how the CFL condition sets the timestep in a finite-volume engine. Push a network to the stability limit and watch what breaks first.
EPANET ↔ SWMM5 Comparator
The two engines share DNA but not vocabulary. A side-by-side Rosetta Stone for sections, parameters, and solver behavior across both INP formats.
SWMM6 Interop Atlas
Where does each SWMM5 feature land in SWMM5+, OpenSWMM, and SWMM6? A living map of the transition, kept current as the alphas ship.
Browse all 99+ apps in the gallery →
Built by someone who's been there since the beginning
Robert Dickinson has worked on the EPA Storm Water Management Model continuously since the 1970s — spanning every major version from SWMM3 through SWMM5 and the forthcoming SWMM5+.
Current Roles
- 🛠️ Water Technologist, Autodesk (2012-2026), now AEC Custormer at Autodesk — supporting InfoWorks ICM, ICM SWMM, and Ruby automation
- 🎓 Chair, SWMM5+ Technical Advisory Committee at the Center for Infrastructure Modeling & Management (CIMM.org)
- 🏛️ EPA SWMM Technical Advisory Committee member
Prior Impact
- Helped embed the SWMM5 engine into InfoSWMM, InfoSewer, and InfoWorks ICM during 18+ years at Innovyze (now Autodesk)
- Contributed to the SWMM4 → SWMM5 transition and EPA QA/QC test suites
- Long-running contributor to OpenSWMM community discussions
YouTube
X / Twitter
LinkedIn
GitHub
"Nurturing SWMM communities for as long as people have been online." — a colleague
After 20+ years of blogging: 1,729+ articles · 150+ Ruby scripts · 99+ interactive utilities
All free. All searchable.