The acquisition of high-resolution elevation data is crucial for accurate townscape modelling, especially for urban areas built upon low-lying subdued terrain. Whilst LiDAR technology is now widely employed to produce townscape digital elevation models (DEMs), it remains a costly product for stakeholders to obtain. It is impractical for these groups to continually procure LiDAR data to capture ever-changing landscapes due to sub-urbanisation. However, the procurement of high-resolution aerial photography remains a routine practice by Australian local government authorities (LGAs) and other relevant management stakeholder groups, and should these datasets be captured correctly, they can potentially be employed to periodically update DEMs when the need arises. Using the low-lying coastal township of Lakes Entrance (Victoria, Australia) as a case-study, this paper proposes an approach which uses existing LiDAR data to initially develop an accurate base elevation model, with subsequent model upgrades being carried out via deployment of digital photogrammetry. This paper also reports a comparison of 3D features extracted via LiDAR-data versus those obtained via photogrammetry-based modelling. The exemplication presented here indicates that synergy of both technologies can result in a cost effective methodology for the construction and maintenance of time-series DEMs, so as to provide the optimal level of spatial decision-support for a range of sustainable development-led activities, such as land use and emergency planning.