2026 ACECNJ Fall Conference

This session presents a case study on the use of two-dimensional (2D) hydraulic modeling to evaluate urban flooding conditions and assess off site impacts which may extend beyond traditional regulatory frameworks. It highlights how system-wide analysis can improve culvert and stormwater design decisions and promote more resilient infrastructure in highly developed watersheds.

Learning Objectives:
Participants will be able to understand how two-dimensional hydraulic modeling can be applied to better represent urban floodplain behavior, including overland flow paths, flood extents, and downstream impacts that are not fully captured in one-dimensional analyses. Participants will also be able to recognize the importance of assessing system-wide and off site impacts which surpass traditional regulatory guidance when designing hydraulic structures.

Audience:
This session is intended for civil and environmental engineers, stormwater and floodplain professionals, transportation planners, and regulatory agency staff involved in the design, review, and management of urban drainage and hydraulic systems. It addresses challenges in aging and undersized stormwater infrastructure in highly developed watersheds, where constrained conveyance systems and changing rainfall patterns increase flooding and downstream impacts. The focus is on engineering design and regulatory decision-making, particularly the use of two-dimensional (2D) hydraulic modeling to evaluate retrofit alternatives, system-wide performance, and floodplain compliance.Key subject areas include urban stormwater management, flood risk and floodplain analysis, culvert and conveyance design, infrastructure retrofit, and downstream impact assessment. Keywords: 2D hydraulic modeling, urban flooding, stormwater infrastructure, flood risk, FHACA compliance, overland flow, and climate resilience.