Before the mid 1990s, a few organizations in International Commission on Large Dams (ICOLD) member countries started to practice risk analysis in the context of dam safety programs. Since that time, several methods and frameworks have been introduced into dam safety and risk analysis. The Risk-Based Profiling System is one of the qualitative approaches. Risk index (RI) methods provide a useful way of characterizing dam safety risks in a systematic, qualitative, and relatively simple manner to help evaluate and prioritize safety issues for individual dams and portfolios of dams.
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. RI methods should be tailor-made with due consideration to the local context, including the size and makeup of a country’s portfolio of dams. A recommended approach is to go through the following three steps:
Assign simple preliminary classification, using readily available information.
Assign scores to a set of appropriate indexes for the specific dam or portfolio of dams.