Dryland salinity, as an externality, has an impact on various public assets, including roads, biodiversity and public water supplies. This has been seen as an important justification for government to take action and internalise the pollution. Economic policy instruments have been identified as a potential solution to the problem, as they may achieve environmental goals at least cost to society. This paper presents a spatial and dynamic model which aims to compare economic instruments for land use change to abate the off-site impacts of salinity on public assets. Preliminary research is presented, along with a discussion of the model’s structure.