This paper describes a discrete event simulation model of post-earthquake restoration for the Los Angeles Department of Water and Power water supply system. It mimics the real-life process in detail, simulating the movement of different types of crews as they inspect, reroute around, isolate, and repair system damage. For any given earthquake, the model provides restoration curves with uncertainty bounds, maps showing the spatial distribution of outages over time, and crew and repair material usage information. Results for the 1994 Northridge earthquake suggest the model is capable of accurately estimating the time and spatial sequence of the restoration. It can be useful for loss estimation and resilience assessment, evaluating the effectiveness of hypothetical restoration strategies, and improving understanding of the restoration process and its key determinants. This is the first application of discrete event simulation to post-disaster water supply restoration, and one of the first for any infrastructure system.