At the Lakes Entrance township (located in East Gippsland, Victoria, Australia, and situated on the shores of an extensive coastal lagoon system known as the Gippsland Lakes), it has been established that during catchment flood events, initial property inundation and damage by floodwaters at certain locations is caused by backflow of estuarine waters via the stormwater pipe network. At such times, a failure of the stormwater discharge system during heavy, extended rainfall is certain. Thus, among interested parties (including insurance companies, their policy holders and land-use planners), scope to claim uncertainty refers to: i.) the initial cause of flooding and property damage at certain locations, and ii.) the relative apportioning of blame to stormwaters or floodwaters for inundation damages. This issue is extremely problematic for all stakeholders. It is demonstrated that, using integrated inundation modelling with reference to a high-resolution DEM and the stormwater pipe network model, sections of the Lakes Entrance townscape at risk of initial inundation via stormwater pipe networks (before coastal floodwaters can overtop seawalls and shorelines) can be visualised with land parcel resolution. Using the same data, and deploying Flash-based visualisation, user-defined flood event scenarios can be visualised. It is argued that this modelling approach provides stakeholders with information regarding the nature of inundation risk via the stormwater network with hitherto unrivalled detail and accessibility. Additionally, this approach provides detailed baseline data and information for any future planning/engineering deliberations regarding amelioration of this inundation risk.