This study introduces "FloodMetrics," an open-source R-package designed to reconcile the gap between cutting-edge hydrological research and practical flood frequency analysis by incorporating advanced stochastic methods rarely used in real-world applications. Utilizing a Peaks Over Threshold (POT) methodology coupled with Copula Theory, the package aims to refine existing hydrologic design standards, particularly crucial in the face of intensifying climate extremes. By examining readily available streamflow gaging data, the research reveals that traditional Annual Maximum Series (AMS) methods can significantly underestimate design floods, especially due to low peak flow of drought years. FloodMetrics offers a comprehensive assessment by introducing previously unconsidered flood characteristics such as flood volume, time to peak, flood duration, peak flow, and interstorm duration into flood risk evaluations. The package offers greater flexibility in flood analysis, notably beneficial in climate-sensitive regions. Conclusively, FloodMetrics presents an invaluable tool for hydrologists, policymakers, and planners, fortifying hydrologic design standards against the growing uncertainties and variabilities introduced by climate change. The SETX/SWLA region, facing heightened climate extremes and vulnerabilities, served as a critical testbed to validate the FloodMetrics framework and software, thereby spotlighting its utility in enhancing hydrological design resilience in an era of escalating climate challenges.
