Original Date: September 25, 2025
Presenters: Kristen Chaffin, PE, Senior Project Engineer; and Brandon Ellefson, PE, Modeling Group Manager | OHM Advisors
Credits: 1.0 PDH | 0.1 CEU | Approved for all Envirocert International, Inc. (ECI) Certifications: Approval #PDH-0189
Cost: Free
As communities face more frequent and intense flooding, advanced stormwater modeling is becoming essential for designing resilient infrastructure to manage community risk.
In this Storm Water Awareness Week webinar, OHM Advisors will explore three high-impact projects that demonstrate how project-tailored modeling approaches and advanced simulation techniques can guide infrastructure investments and improve flood mitigation strategies.
Attendees will gain a practical understanding of how recent advances in stormwater modeling tools can help identify management solutions to some of today’s most pressing water infrastructure challenges.
Learning Objectives:
- Learn from three real-world case studies where data-driven modeling informed innovative, high-impact flood mitigation solutions.
- Explain the antecedent moisture model, an alternative approach to applying design storms to stormwater systems.
- Explore different modeling approaches and simulation tools used to address complex stormwater challenges.
About the Presenters
Kristen Chaffin, PE
Senior Project Engineer, Environmental and Water Resources Group, OHM Advisors
Kristen Chaffin is a senior project engineer specializing in hydrologic and hydraulic modeling within OHM Advisors’ Environmental and Water Resources Group. Her expertise lies in modeling the fate and transport of contaminants in both surface water and groundwater systems, leveraging platforms such as Visual MODFLOW Flex, PCSWMM, and HEC-RAS.
Kristen has played a key role in developing tailored modeling tools to support project-specific needs—delivering actionable insights for infrastructure design and environmental remediation. With a BS and MS in Civil and Environmental Engineering from the University of Michigan, her academic focus on pollutant degradation and transport continues to inform her work addressing today’s most complex stormwater challenges.
Brandon Ellefson, PE
Modeling Group Manager, Environmental and Water Resources Group, OHM Advisors
Brandon Ellefson leads OHM Advisors’ modeling team as a project manager in the Environmental and Water Resources Group. With deep expertise in hydrology, hydraulics, and hydrodynamics, Brandon has developed and applied models such as DELFT3D-FM, EFDC, SWMM, and HEC-RAS to guide planning and design for a wide range of projects—from CSO system optimization and green infrastructure to watershed planning and coastal resilience.
His work is grounded in robust data collection, utilizing both real-time and long-term field techniques to inform model accuracy and effectiveness. Brandon brings a forward-thinking, data-driven approach to stormwater modeling that empowers communities to mitigate flood risk and make smarter infrastructure investments.
Produced in Partnership with Storm Water Awareness Week
Course Includes
- 1 Lesson
- 1 Quiz
- Course Certificate
