Topics

Explore by subject

Find your way to the model

Six starting points for exploring urban drainage modeling: how water moves, where it comes from, how engines compare, how networks are built, how model files connect, and how we teach the ideas behind them.

These topic hubs organize articles, interactive tools, code, and worked examples around a modeling question—not simply the date something was published. Choose the subject closest to the problem you are trying to solve.

01 · How water moves

Hydraulics

Explore flow through pipes, channels, junctions, storage, and hydraulic structures. Start with the physical behavior, then connect it to the equations, numerical methods, and results that appear in a drainage model.

Dynamic-wave routing · Backwater · Surcharge · Flooding · Force mains · Pumps and controls · Time steps and stability

02 · Where the water comes from

Hydrology & RDII

Follow rainfall through the catchment and into the drainage system. Explore runoff generation, infiltration, and rainfall-derived infiltration and inflow (RDII), with attention to the assumptions and parameters that shape the resulting hydrograph.

Rainfall inputs · Subcatchments · Infiltration · RTK unit hydrographs · LID · Water quality · Wet-weather response · Calibration

03 · Check the solver

Engine Comparisons

Compare modeling engines, versions, and builds using explicit assumptions and reproducible tests. Look beyond whether two curves appear similar: inspect inputs, routing options, continuity, time steps, and the numerical differences behind the results.

SWMM generations · Solver behavior · Native and browser builds · Regression testing · Benchmarks · Verification evidence

04 · Build a useful test model

Network Generators

Create networks for learning, experimentation, and software testing. Use controlled layouts and repeatable parameters to isolate a hydraulic question, investigate model scale, or construct a benchmark without drawing every node and link by hand.

Synthetic networks · Parametric layouts · Test cases · Connectivity checks · Model export · Repeatable experiments

05 · Open the file, keep the model

File Formats

Understand how model information is stored, extracted, and transferred. Explore readers, converters, and scripting workflows with attention to what survives a transfer, what changes meaning, and what must be checked before the converted model is run.

SWMM input files · ICM formats · Data extraction · Ruby workflows · Crosswalks · Conversion ledgers

06 · Make the behavior visible

Teaching

Build intuition through worked examples, interactive explanations, and small models with a clear purpose. Connect a parameter change to a physical response, a solver decision, and an output that can be explained—not merely accepted.

Interactive demonstrations · Worked examples · Modeling fundamentals · Visual explanations · Exercises · Model review

One purpose: SWMM enablement

These six topics share a practical goal: remove the obstacles between an engineer and a working, understandable model. Sometimes that means explaining an equation. Sometimes it means opening an unfamiliar file, automating a repetitive task, or checking a result that deserves a closer look.

Start with your question. Follow the evidence. Reach the hydraulics faster.