Earthquake is a potential hazard for communities in seismically active regions, and fire following earthquake, a cascading multi-hazard event, can cause major social and economic losses. A number of fire ignitions across a community could be expected following an earthquake; however, the key is to prevent fire from spreading and to confine the fire to the location of origin. Previous historical events show that it is often the lack of water pressure and flow that prevents firefighters from suppressing fires. Dependency of water and electric networks is one of the factors that could affect availability of water, while pump stations, wells, and water treatment plants require power to operate. This chapter starts with an overview of existing tools and models on fire following earthquake and identifies the knowledge gap, in properly modeling the water availability for firefighting purposes, in existing tools. The chapter describes a methodology, based on network analysis, to quantify water flow and pressure following an earthquake while including the dependency of components to power. It is shown that ignoring explicit dependence of the electric network on the water network may provide inaccurate and unconservative predictions of available water pressure at fire hydrants.