Portfolio Risk Assessment Using Risk Index

This Technical Note provides detailed information on the Brazilian risk classification system using the RI approach and the Indian RI system for the initial risk screening of a large portfolio of existing dams. Annex A provides basic information about the RI approach used in Quebec, Canada, for its dam classification system. These RIs are used for prioritization of required remedial works and other safety requirements. It should be noted, however, that RI is also a basic tool for preliminary level risk analyses for portfolios of dams and initial screening of risky dams, which may need to be supplemented by more advanced methods, depending on the type and potential risk of the dams. Because RI largely relies on visual inspection of the dams’ conditions, some critical failure modes could be missed. underestimated, or overestimated. In the higher risk cases, or whenever deemed appropriate, more detailed risk analyses, such as potential failure mode analysis (PFMA), can fill some of the gaps.