Managing stormwater effectively is essential for sustainable site development and flood prevention. The National Stormwater Calculator (SWC) is a powerful web-based tool developed by the U.S. Environmental Protection Agency (EPA) that estimates runoff, retention, and low-impact development (LID) performance for any location in the U.S. This course provides a step-by-step guide to using the SWC, participants will learn how to assess hydrological conditions, incorporate climate projections, and apply LID controls to enhance site resilience. Whether you are an engineer, planner, or property developer, this course will empower you to make data-driven decisions in stormwater management.  Course Outline Introduction to the National Stormwater Calculator (SWC)

• Purpose and capabilities
• Key updates in Version 3.4.0

Understanding Site Inputs

• Location and climate data
• Soil type and drainage classification
• Land cover and topography considerations

Hydrologic Modeling and LID Controls

• Rainfall and runoff estimation
• Evaluating pre- and post-development conditions
• Applying LID practices: rain gardens, green roofs, infiltration basins, and more

Climate Change Impacts on Stormwater Management

• Using future climate projections in SWC
• Evaluating site vulnerability and adaptation strategies

Interpreting SWC Results

• Rainfall retention frequency and runoff statistics
• Comparing scenarios for decision-making

Practical Applications and Case Studies

• Urban and suburban stormwater management examples
• Applying SWC insights to real-world projects

Stormwater management is critical for maintaining water quality, reducing flooding, and building climate resilience. The National Stormwater Calculator (SWC) is a user-friendly tool that helps professionals estimate stormwater runoff and evaluate the effectiveness of green infrastructure solutions. This course provides a step-by-step guide on how to use the SWC Web App, analyze site data, and implement LID practices to improve stormwater sustainability. This course is ideal for civil engineers, environmental consultants, urban planners, landscape architects, and developers involved in stormwater management, site development, and green infrastructure planning.

Learning Objectives

At the successful conclusion of this course, you’ll be able to identify and discuss:

• Understand the key features and applications of the National Stormwater Calculator.
• Learn how to input site-specific data to generate accurate runoff estimates.
• Analyze the impact of land cover, soil type, and drainage on stormwater behavior.
• Apply Low Impact Development (LID) practices using the calculator’s modeling tools.
• Incorporate climate change projections to assess long-term stormwater risks.
• Interpret estimation results for capital and maintenance planning.
• Compare pre-development, post-development, and LID-optimized scenarios.
• Use SWC-generated insights to support stormwater management strategies.
• Gain hands-on experience applying the tool in urban and rural contexts.