Many glacial lakes in the Himalayas are held in place by natural sediment dams, which are prone to collapse, causing a glacial lake outburst flood (GLOF). This study models a GLOF as a process chain, in which an avalanche enters the lake, creates a large wave that erodes the sediment dam, and produces a flood downstream. Results indicate that Imja Tsho presents little hazard for the next 30 years, but the model is replicable and should be used at other lakes that may present greater hazard.