<p>There is increasing evidence that upstream depressional wetlands (UDWs) play a crucial role in regulating catchment hydrology. However, in cultural landscapes, most UDWs have been drained and converted to agricultural land. They are often overlooked in historical wetland inventories due to their small size and degraded ecological state. Identifying their historical presence could offer opportunities for restoration, improving the hydrological regime of the catchment. This study uses the Topographic Position Index (TPI) and a soil-based wetland map to develop a statistical model for locating these lost, small, drained UDWs. The model effectively predicted wetlands on the soil-based map (AUC &gt; 0.8) and identified many smaller wetlands which were not captured by the soil survey. This study demonstrates the use of TPI as a relevant method to identify overlooked smaller wetlands. This approach is highly transferable and can be applied to other areas with mild topographical variation.</p>