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Meeting notes

Committee meeting · February 12, 2026

New officers, a tool-neutral charter, and new task committees on design storms, SWMM testing and teaching tools.

February 12, 2026 Virtual meeting 17 attendees

Summary

The committee welcomed five new members and confirmed new officers: Erica McKenzie (Chair), Michael Gregory (Vice Chair) and Scott Jeffers (Secretary). Members affirmed that this is a tool-neutral committee open to every stormwater modeling platform.

The committee formed a Design Storm National Standard task committee led by Mitch Heineman and agreed to form a task committee on SWMM testing and contributions led by Bryant McDonnell. The Real-Time Systems task committee continues under Robert Dickinson with support from Bryant McDonnell, and the Teaching Tools task committee was renewed under Michael Gregory and Scott Jeffers. Robert Dickinson presented on AI-assisted tool development, and Scott Jeffers gave an update on new SWMM development.

Decisions

Action items

  • Bryant McDonnell — Complete the task committee paperwork for the SWMM testing / contributions task committee and report on the plan and team at the next meeting.
  • Bryant McDonnell — Work with Michael Tryby and Constantine Karos to develop a standard set of tests that any version of SWMM can run to qualify.
  • Mitch Heineman — Lead the new Design Storm National Standard task committee with support from Constantine Karos and Elango Thevar.
  • Scott Jeffers — Coordinate the design storm group by email and host its work product online.
  • Scott Jeffers — Email Robert Dickinson and Bryant McDonnell to coordinate the Real-Time Systems task committee.
  • Erica McKenzie — Share the annual report form for the Real-Time Systems task committee to document continued activity.
  • Scott Jeffers — Discuss with Michael Gregory expanding the OpenSWMM site to host EWRI-branded training materials.
  • Scott Jeffers — Get feedback from Marcus Quigley on an open data task committee as a topic for the next meeting.
  • Robert Dickinson — Prepare a proposal for the legacy committee for discussion at the EWRI Congress in April.
  • Elango Thevar — Present a future Modeler Minute on using an AI assistant to run and discuss SWMM (INP) projects.
  • Scott Jeffers — Post the meeting notes on the website and send them to members, with individual email threads for each interested group.

Discussion

Welcome and new members

Scott Jeffers introduced Elango Thevar, a water resources engineer working on AI and open-source tools for SWMM and EPANET. Shirley Clark introduced her Ph.D. student Omid Razavi, who studies soil compaction and infiltration in SWMM. Also joining were Kody Schouten, a project engineer focused on HEC-RAS and StormCAD; Constantine Karos, a hydraulic modeler interested in the SWMM engine; and Julia Atayi, a student at Morgan State University.

Officer transition

With Dayton Marchese stepping down, Erica McKenzie moved from Vice Chair to Chair, Michael Gregory from Secretary to Vice Chair, and Scott Jeffers joined as Secretary. Erica emphasized that officers organize meetings, while members set the committee’s direction and staff its task committees.

Purpose of the committee

Members discussed the scope of the committee. New members highlighted GPU-accelerated 2D modeling, AI-assisted workflows, and making the SWMM engine more modular and better tested. Scott Jeffers noted that this is the Stormwater Modeling Committee, not a SWMM committee, and the group agreed it is a tool-neutral committee open to HEC-RAS, HydroCAD and every other platform. Mitch Heineman observed that SWMM is the only open-source engine among those discussed.

Task committee expectations

Michael Gregory asked members to commit only to work they are enthusiastic about and can deliver, favoring fewer, achievable task committees. Scott Jeffers offered EWRI/ASCE co-branding as a way to support members’ community projects, as long as the content is educational rather than promotional.

Real-Time Systems

The task committee had been inactive and was considered for sunset. Robert Dickinson volunteered to lead it, citing his SWMM Anywhere prototype that builds SWMM models from OpenStreetMap data, and Bryant McDonnell offered support. Erica McKenzie confirmed the committee continues and will need an annual report.

Teaching Tools

Deliverables to date include YouTube tutorials, a workshop at the 2025 Congress in Alaska, and an open online SWMM manual, which Robert Dickinson has indexed against the engine source. The near-term goal is training material for the new SWMM release ahead of the April workshop. The task committee was renewed.

Design Storm National Standard

Mitch Heineman proposed a task committee on design storm standards: shaping storms that conform to NOAA Atlas depths at all durations and replacing outdated SCS distributions. Shirley Clark reported that preliminary Atlas 15 volumes for the contiguous U.S. are expected in late 2026 to early 2027, with final release in 2027. Mitch will lead, with Constantine Karos as deputy and Elango Thevar contributing.

SWMM testing and contributions

Bryant McDonnell proposed a standard test suite that any SWMM version or fork must pass. Constantine Karos noted that legacy tests are outdated and too simple. Members agreed the benchmarks need judicious version control and should build on the standard INP, OUT and RPT formats, with test models hosted in a public GitHub repository. A task committee will be formed to make contributing to SWMM easier.

ASCE2027

Shirley Clark noted that the committee’s work aligns with ASCE’s resilience themes for the unified ASCE2027 conference in Philadelphia and encouraged members to submit content.

AI-assisted development

Robert Dickinson demonstrated a series of interactive tools built with AI coding assistants, including browser-based WebAssembly builds of the SWMM engine, comparisons across SWMM 3, 4 and 5, and an interactive version of Bill James’s rules for responsible modeling, all published openly on GitHub.

New SWMM development

Scott Jeffers reported that a beta of the new SWMM is approaching external testing, with roughly three-times faster runtimes, a new interface and a path toward 2D modeling. Initial startup activity is funded by an EWRI innovation grant. Bryant McDonnell and Robert Dickinson stressed the importance of an open-source license and community contributions. Michael Tryby clarified that EPA cannot endorse third-party products and that SWMM has historically been source-available rather than formally open source. EPA is expected to make a statement about the future of SWMM at the April meeting.

Attendance

  • Mike Gregory
  • Scott Jeffers
  • Bryant McDonnell
  • Julia Atayi
  • Robert Dickinson
  • Mitchell Heineman
  • Shirley Clark
  • Kody Schouten
  • Erica McKenzie
  • Elango Thevar
  • Omid Razavi
  • Michael Tryby
  • Ben Hodges
  • Ahmad Payab
  • Harry Zhang
  • Bruno Sousa
  • Constantine Karos

These notes were generated from the meeting recording with AI assistance and edited for clarity and length. Contact the secretary with any corrections.