The U.S. Army Corps of Engineers (USACE) Risk Management Center (RMC) developed RMC-BestFit to streamline and strengthen flood frequency analysis (FFA) for flood risk management, planning, and dam and levee safety applications. This freely available software uses Bayesian methods to integrate diverse sources of hydrologic information—such as systematic and historical records, paleoflood data, rainfall-runoff modeling, and expert judgment—into a unified probabilistic framework.

This lecture provides an overview of RMC-BestFit’s core features, including support for both stationary and nonstationary analyses, uncertainty quantification, and incorporation of complex data types such as interval and censored observations. Through a pair of case studies, we demonstrate the practical use of RMC-BestFit in evaluating flood hazard for high-consequence infrastructure. One case study focuses on a traditional stationary analysis using multiple data sources, while the other highlights a nonstationary flood frequency analysis incorporating climate-informed trends. Together, these examples illustrate how RMC-BestFit supports transparent, defensible risk assessments and informs decision-making under uncertainty.