When is a Dam High Hazard?

Abstract Only - one of the most important aspects of a dam safety program or evaluation of a particular dam is the correct assessment of the potential downstream hazard due to a failure of the dam. A high hazard classification is most significant in that it almost always means loss of human life or significant property damage to downstream areas. such a hazard classification is intended to create a level of design, construction and inspection that will provide reasonable protection to the public and flood-prone areas below the dam while trying to maintain the economic feasibility of the dam to the owner.
The determination of criteria or guidelines to be used in assigning hazard classification is not an exact science. Each regulating entity, engineer, etc. must determine the level of protection to be provided and establish criteria accordingly. This paper will present some ideas and topics to be considered in determining when a dam is high hazard. The obvious case of loss of human life will be discussed. In addition, ideas for consideration of determining significant property damage will be presented. Other topics to be considered and discussed include economic damage (dollar amounts, etc.), damage to public utilities (water and sewer lines, power lines, etc.), environmental damage, and damage to public roads and railroads.
In conclusion, a discussion of the importance of making the correct hazard determination will be presented. This will include a brief discussion of available techniques to accurately determine when a dam is high hazard. Applying reasonable criteria or guidelines and available flood routing techniques made easier by the age of personal computers, eliminates much of the guesswork and uncertainty in determining a hazard classification.