Whirlpool in the reservoir in the vicinity of the dam.
A whirlpool is the most serious condition that can be observed because it is caused by
flow through a large channel in or under the dam that will likely enlarge until the dam is
breached. Initiation of the Emergency Action Plan (EAP) to begin evacuation should be
undertaken immediately. The reservoir should be lowered as rapidly as possible.
Attempt to plug the entrance of the whirlpool with riprap or large stone. If the plug
attempt decreases the flow, add progressively smaller material such as gravel, sand, etc.
Locate the exit point downstream and attempt to construct a ring dike or filter berm to
retard the removal of material.