Table 3: Classification of dams in terms of incremental consequences of dam failure

Incremental consequence categories A. incremental consequences of failure from floods >IDF Incremental consequences of failure from other causes
Incremental Hazeard-to-Humans Index, IhtHI (plus suggested corresp. IDF) Economic, social & environmental consideration Life safety consideration Economic, social & environmental Consideration
Very High >100 (IDF: 100,000-yr/PMF) Extreme damage Large number of lives lost Extreme damage
High 1 to100 (IDF: 1000-to100,000-yr/PMF) Large damage Some lives lost Large damage
Low <1 (IDF: <1000-year) Moderate damage Less than one life lost Moderate damage
Very low 0 Minor damage beyond owners property No life lost Minor damage