Contamination of a public water supply distribution system would have far-raging public health and 
economic effects.  Emergency response decision-makers need a tool for quickly calculating resources 
requirement in the aftermath of a contamination incident.
A model is needed to describe the potable water distribution system itself and the cascading effects of 
a disruption of that distribution system on other public institutions such as hospitals, transportation 
networks, etc.   In this paper we present a system dynamics model describing a potable water 
distribution system that serves an urban area.  This model is a component of the Critical Infrastructure 
Protection Decision Support System (CIP-DSS) project, which models the dynamics of a set of coupled 
individual infrastructures.  We investigate the interdependencies of potable water distribution systems 
on other critical infrastructures merging our model with other infrastructure models developed under 
the CIP-DSS project.  The main focus of this work is to study the consequences of a disruption on a 
potable water distribution system.  For this purpose we analyze the effects on public health and the 
economic consequences resulting from contamination of a public water supply.