The Risk-Based Profiling System (RBPS), developed by the U.S. Bureau of Reclamation in 2000, was a qualitative approach that applied principles of risk for dam safety program management. Use of the RBPS produces a risk index (RI), a product of the potential life loss associated with dam failure and response under static, hydrologic, and seismic loading. While risk methodology and analysis has continued to evolve, the NRCS still considers the RI a useful tool in prioritizing funding for risk reduction and rehabilitation projects for the roughly 12,000 NRCS-built flood detention dams across the country, including making development of a dam’s RI a requirement for specific project funding considerations.
The authors of this paper have performed well over 100 NRCS dam assessments in Texas, including development of individual RIs. We have also applied the more modern and standard risk principles for FERC, USACE, and the U.S. Bureau of Reclamation. This paper will provide an overview of various methodologies, including the FEMA Project Prioritization Tool. It will discuss the methodology for calculating RIs, potential ‘blind spots’ in this methodology and how it compares to more modern portfolio risk analysis frameworks for such as FERC, USACE, and Reclamation. Discussion will include key differences in the NRCS RI development of the risk index value without development of site-specific failure modes and the lack of tolerable risk levels, and potential improvements to the RI methodology.
