The hazard potential of the dam needs to be updated over time to take into account changes in the area that might be affected in the event of a dam failure.
Hazards relate to impact of dam failure on:
(1) loss human life
(2) economic cost
(3) damage to the environment
(4) damage to lifelines (roads, rails, bridges, utilities, etc)
If there increased development within the failure area, then the hazard potential will increase. A dam built in an undeveloped area may have low risk when built, only to have significant risk over time.
Factors affecting the change in hazard:
(1) change in population
(2) change in structural and economic development
(3) change in the environment
(4) change in lifelines
(5) structural modification of the dam
(6) change in how the dam is managed, including emergency response