This model simulates a failure of a dam embankment when the water level remains above a specified level for more than a defined amount of time. If the water level is not above that level for more than the time limit, then it is not considered a failure. This is done using an Integrator element that keeps track of the cumulative time the embankment is submerged. Once the water level drops back below that threshold level, the timer is reset to zero again. Note that the event triggers use the trigger type called "At Stock Test" which causes GoldSim to insert an unscheduled time step at exactly the moment the event happens.
When you run this model, make sure you enable the ability to include unscheduled updates (see Advanced Time Settings). Viewing the "Failure History" plot as seen below, you will see that a failure is only triggered if the water level rises above the limit and stays at that level for more than the time limit of 2 hours.