Low relief, heavily human-impacted landscapes like those of the Prairies in south-central Canada have received little attention in previous hydrological research. Here, the rainfall-runoff relationship in the context of both a field-based investigation and an empirical model is examined in an effort to provide insight into Prairie hydrology. Rainfall and water level data were collected for nested sub-watersheds of the Catfish Creek watershed, a 642 km2, near-level, mixed land use and engineered Prairie watershed. First, the dataset is examined for runoff controls. Second, the history of the United States Curve Number Method is reviewed and its initial abstraction ratio examined against collected field data to determine the applicability of a single, constant ratio to Prairie landscapes. Overall, the results indicate that Prairie runoff generation processes differ significantly from those of humid, pristine catchments of higher relief and a conceptual model is proposed with that regards.