This paper presents a dam safety decision-makers, and owners, perspective of the emerging and arguably juvenile discipline of dam risk management using formal, analytically based methods of risk analysis. It is founded on almost ten-years of detailed investigations into all aspects of risk analysis as applied to dams including several experimental applications of proposed approaches by BC Hydro. The paper provides a basis for concluding that while formal analytically based dam risk management can be expected to endure in the long term, its form will continue to evolve and necessarily will be somewhat different to what was (and still is by some) envisaged in the early to mid-1990's.
This paper focuses on water retaining embankment dams in keeping with the geotechnical theme of the conference. Although some of the principles discussed regarding dam risk management will equally apply to tailings impoundments and concrete dams. According to the world register of dams there are about 30,000 significant water retaining embankment dams throughout the world. Collectively these dams have provided tremendous benefit to the development of civilization, and continue to provide for our improving standard of living. The earliest known dams from about 4000 B.C. until well into the 1800's A.D. were used primarily for irrigation and water supply. Some of the ‘ancient’ dams are still in use today, a testament to potential longevity of embankments if well designed, sited, constructed and maintained. It was not until about the first millennium A.D. that dams exceeded 10 m in height. Near the end of the 19th century, both numbers and heights of dams began to increase, reaching heights of more than 20 m, and with the later introduction of concrete dams the trend to increasing height became marked. The 1920's saw the increasing construction of large dams for hydroelectric power.