SMALL DAMS PETITS BARRAGES

8. GUIDELINES ON EMERGENCY ACTION PLAN (EAP)
8.1 INTRODUCTION
The EAP is a useful tool intended to minimize the consequences of a dam failure or
malfunction, regarding the population living downstream. In the last 30 years, several countries
became aware of the new approach requested by modern society and developed regulations
on this matter, creating a dam classification system according to potential downstream hazard
and establishing the EAP for dams with a high significant risk
Initially the EAP was applied to medium and large dams, and nowadays it is also applied to
small dams as a consequence of the great number of such structures and that 87% of the
victims related to dam failures have been caused by small dams, according to the experience in
the United States - Bureau of Reclamation, along the period from 1970 to 1997. It is interesting
to point out from this experience, that 99% of the victims were situated along the 24 km
downstream of the dams.
The Emergency Action Plan typically falls under the preventive measures to be taken regarding
dams safety. For many years these aspects have been taken into account in different
regulations and more demanding safety criteria has been established for those dams in which
failure or malfunction, even with a very low probability, may cause severe consequences to the
downstream population.
The purpose of this document is to provide findings, recommendations and strategies to
significantly increase the application of Emergency Action Plans to high hazard small dams.
The recommendations and strategies can be implemented by policymakers, state and local
dam safety officials and dam owners, with the collaboration of the state and local emergency
agencies. An EAP is essential for small dam owners and first responders in the event of a dam
failure resulting from a natural event (such as a big storm or earthquake), from an accident or
from a manmade event.
8.2 HOW TO DEVELOP AN EMERGENCY ACTION PLAN
The process of developing an EAP for a small dam generally follows the next steps, as pointed
out by Abadjiev [2]:
Determine the potential inundated area downstream in case of a dam failure. Two scenarios
are to be considered: inundation at maximum probable flood through the spillway without
dam failure, and inundation with dam failure. Different failures according to their reasons and
development are to be considered as overtopping, piping, etc.
Prepare inundation maps clearly indicating the flooded areas and the time at which the wave
will reach the downstream settlement or important area.
Determine and identify the situations and events that could initiate an emergency action and
specify the corresponding actions to be taken and by whom. Develop clear instructions to
explain how the operation staff must react before and during emergency.
Identify all entities, jurisdictions, agencies and individuals, who will be involved in the
emergency actions. Coordinate the development of the EAP with all parties. This interaction
should include the discussion of an emergency operation center and discussion of the
evacuation with destinations, priorities and procedures, post-flood actions (recovery and
cleanup) and all other measures. These discussions must be concise and productive, and
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