The Stairs and the Lift
Ephemeralization, checking and hand-thinking for SWMM5, SWMM6 and models in general
SWMM Enablement · 2026-10-31 · companion to the SWMM App Complexity Meter v1.4 (meter-core 1.2.0, baseline HC-2026-10-31-c)
This tab starts from a short essay Bob shared. It makes one argument in three moves. Here … Read the rest
How to use AI to run, check and compare engines without fooling yourself.
Over the past year I have built hundreds of apps with AI. The lesson that matters: AI makes comparisons cheap, so the checks have to be strict.
My rules for any comparison: the same input file, .out … Read the rest
The same network in two engines, with the Ruby scripts and apps that compare them.
I spent 18 years as Product Sector Leader for InfoSWMM and InfoSewer at Innovyze, and I have written more than 440 Ruby scripts for InfoWorks ICM. This page shows how SWMM5 and ICM differ on … Read the rest
How EPA SWMM 5.2.4 computes runoff, routing and everything between, one app at a time.
Each app here opens one part of EPA SWMM 5.2.4: the source file, the equation and the numbers it produces. Many of them run the real engine, compiled to WebAssembly, in your browser.
The oldest … Read the rest
The engines from 1971 to now, rebuilt and running in your browser.
SWMM began in 1969 to 1971 as an EPA project with Metcalf & Eddy, the University of Florida and Water Resources Engineers. I went to Florida in 1973 to work on it, and I have worked on SWMM … Read the rest
More than fifty years of SWMM, organized six ways. Pick the question you have. Each topic page gives you posts to read, apps to try, an example to work through and the code behind it.
The order runs from where SWMM came from, through the inside of SWMM5, to ICM, … Read the rest
Fixing EPA SWMM 5.2.4, One Proven Defect at a Time
The rounded-bottom bug, how far it reaches, and a fixed 5.2.4 built from the HydroCouple code review
Prepared for Robert (Bob) Dickinson · October 19, 2026
In October 2026 Caleb Buahin set an AI agent on EPA SWMM 5.2.4 and … Read the rest
The Water Decides
Told in the manner of Isaac Asimov’s science essays
Robert (Bob) Dickinson · SWMM Enablement
App version 1.1 · 17 October 2026
Engines: EPA SWMM 5.2.4 and OpenSWMM 6.0.0-alpha.4 (swmm6_rel 64d517f), both compiled to WebAssembly
Units: US customary (ft, s, cfs)
This is an app i made from a optimizer i saw on X called Nesterov gradient optimizer. I has a SWMM5 and SWMM6 engine, is connected to thousands of SWMM models and allows you to calibrate the model. Calibration is key for modeling as models have a lot of parameters.Two
A Harvard study warned that AI intensifies work. Here’s what that looks like when the work is stormwater modeling and the worker has half a century of hydraulic knowledge to unleash.
Updated July 2026.
I’ve been exploring an unusual intersection: hyperbolic geometry and hydrological modeling. The result is a web-based tool that generates subcatchment tessellations for EPA SWMM5 using Möbius transformations on the Poincaré disc. It looks visually interesting, the exported work as test models … Read the rest
The problem with using 50 year old simple models or even test models that started out as real models as we did in the SWMM5 redevelopment project are they are too nice for the most (with exceptions). This app uses strange attractors to make complex visually interesting models that look … Read the rest
Helping across the full stormwater spectrum: SWMM (50+ yrs), InfoSWMM/ESRI (20 yrs), InfoWorks ICM (15 yrs), & Autodesk AEC Collection (5 yrs) Grandpa (10 yrs)
December 14, 2025
There is quite … Read the rest
Helping across the full stormwater spectrum: SWMM (50+ yrs), InfoSWMM/ESRI (20 yrs), InfoWorks ICM (15 yrs), & Autodesk AEC Collection (5 yrs) Grandpa (10 yrs)
December 6, 2025
This is an app that I always wanted to make … Read the rest
](https://www.linkedin.com/in/robertdickinson/)
Helping across the full stormwater spectrum: SWMM (50+ yrs), InfoSWMM/ESRI (20 yrs), InfoWorks ICM (15 yrs), & Autodesk AEC Collection (5 yrs) Grandpa (10 yrs)
December 6, 2025
This is a simple yet … Read the rest
](https://www.linkedin.com/in/robertdickinson/)
Helping across the full stormwater spectrum: SWMM (50+ yrs), InfoSWMM/ESRI (20 yrs), InfoWorks ICM (15 yrs), & Autodesk AEC Collection (5 yrs) Grandpa (10 yrs)
November 30, … Read the rest
](https://www.linkedin.com/in/robertdickinson/)
Helping across the full stormwater spectrum: SWMM (50+ yrs), InfoSWMM/ESRI (20 yrs), InfoWorks ICM (15 yrs), & Autodesk AEC Collection (5 yrs) Grandpa (10 yrs)
August 8, 2025
Introduction
As … Read the rest
](https://www.linkedin.com/in/robertdickinson/)
Helping across the full stormwater spectrum: SWMM (50+ yrs), InfoSWMM/ESRI (20 yrs), InfoWorks ICM (15 yrs), & Autodesk AEC Collection (5 yrs) Grandpa (10 yrs)
July 28, 2025
Are you a … Read the rest
](https://www.linkedin.com/in/robertdickinson/)
Helping across the full stormwater spectrum: SWMM (50+ yrs), InfoSWMM/ESRI (20 yrs), InfoWorks ICM (15 yrs), & Autodesk AEC Collection (5 yrs) Grandpa (10 yrs)
May 13, 2025
Introduction
Bridging Decades with AI … Read the rest