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
Where OpenSWMM 6 meets ICM, and where they part ways.
This is the newest of the six topics, and it grows through December 2026. It starts with the Control Section Lab: one reference solver, EPA SWMM 5.2.4 and OpenSWMM 6 compiled to WebAssembly, and the documented ICM 1D rules, which … 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
OpenSWMM 6 from the source code up: new solvers, 2D, plugins and the GUI.
OpenSWMM 6 is the open successor to EPA SWMM5, built by Caleb Buahin and the OpenSWMM team at HydroCouple. I don’t write the engine. I build apps that open it up, run it next to SWMM5 … 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
SWMM ENABLEMENT · TOOLING NOTE
Claude Chat Archive
How the single-file searchable archive of three years of conversations is built and how it works
Robert Dickinson · Build of 14 October 2026 · Document written 18 October 2026
The archive is one HTML file. Open it with a double-click, with … Read the rest
SWMM PDF WIZARD
How It Works
From a SWMM5 or SWMM6 model set to a finished PDF report: the file readers, the report layout, the pdfcraft engine in the browser, and the bridge your other apps use.
App version SWMM PDF Wizard 1.0.0
PDF engine pdfcraft-cli 0.8.0 (commit 9e5b70d, 16 … 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
EPANET Total Head Explorer
A Detailed Summary of the Interactive Educational Tool
https://epanet-total-head-explorer.netlify.app/
The EPANET Total Head Explorer is an interactive, browser-based educational tool designed to demystify how EPANET (the industry-standard water distribution modeling software from the U.S. EPA) calculates total head at every node in a water network. Built … Read the rest
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.
The InfoSewer to ICM InfoWorks — Network Import Process app is an interactive, browser-based guide that documents a Ruby automation for migrating InfoSewer collection-system models (stored as .IEDB folders of DBF files) into Innovyze InfoWorks ICM. It walks an engineer through the full 10-step … Read the rest
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 PoincarĂ© 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
