Some of the tactics considered in PAWN involve raising the water level in two large freshwater lakes (the IJsselmeer and Markermeer) in order to store more fresh water for use in the summer dry period. This volume describes models that PAWN developed and used to estimate the change in safety, as measured by the probability of flooding, which would result from these tactics. Two models, the IJsselmeer Filling Model and the Dike Safety Model, are described and the reliability of the results obtained by using these models are discussed.
