What This Tutorial Covers

This tutorial serves as a hands-on guide for professionals using GeoSWMM, with a focus on the practical application of Low Impact Development (LID) modeling for stormwater runoff reduction and water quality control. It is intended for users who already have a working knowledge of hydrology, hydraulics, stormwater management modeling, model input data in ArcGIS Pro and the use of EPA SWMM elements and flow routing methods for representing drainage systems.

The tutorial walks users through the modeling of two LID control alternatives: Filter Strips (FS) and Infiltration Trenches (IT). It emphasizes how these controls function as hydrologic source controls that operate at a smaller scale than conventional subdivision-level drainage structures. Unlike the detention pond presented in Tutorial 03, which serves as a larger-scale control measure, the LIDs in this tutorial rely on infiltration and distributed small-scale storage to reduce runoff volume and improve stormwater quality. These skills are especially relevant for engineers and planners seeking sustainable and decentralized approaches to stormwater management.

Users will learn how to represent Filter Strips and Infiltration Trenches in GeoSWMM, understand their role in reducing overall watershed runoff, and evaluate how small-scale infiltration-based controls can contribute to both runoff quantity management and water quality improvement. This tutorial complements the GeoSWMM User’s Manual by offering a structured, example-driven walkthrough of real-world modeling scenarios.

The following section begins a step-by-step demonstration of the worked example project, guiding users through each stage of setting up and evaluating Filter Strips and Infiltration Trenches in GeoSWMM.