The Department of Geoinformatics and Cartography of the University of Wrocław, Poland, is host institution of a project, financed by the National Science Centre in Poland, whose objective is to predict riverflow in real-time. If inundation is predicted, the problem of the verification of the overbank flow prognosis arises. This verification can be attained by utilizing an unmanned aerial vehicle that may be used for remote sensing applications. The unmanned aerial vehicle in question can take sequential photos with the unprecedented resolution of 3 cm/pix. Both the resolution and the opportunity for frequent flights – due to the low cost of the entire operation – allow us to compare prediction maps showing the forecasted overbank flow during an extreme hydrological event with the true observation obtained from the air. Although such verification is site- and event-specific, it can provide us with an objective technique for checking our system in a spatial domain. The main part of the system, known as HydroProg, produces multimodel ensemble hydrograph predictions and compares single-model prognoses; visualizations of them are then published in a web map service. The spatial predictions, along with the aerial orthophoto images, will also be presented online so that the user is able to observe the functioning of the system. Regular research flights have been carried out in Kłodzko County since 2012. The study areas correspond to sites where our Partner, the County Office in Kłodzko (SW Poland) – owner of the Local System for Flood Monitoring in Kłodzko County – has automatic gauges, and thus spatially reflect the hydrologic observation network. The aforementioned aerial module is experimental and will be incorporated into the entire system.