The Role of Wetlands during Low Frequency Flooding Events in the Red River Basin

Abstract

Research studies have identified the functions and the numerous and wide ranging benefits that wetlands offer to society. The role that wetlands play in low frequency flooding events, however, is one function for which further research is necessary. Through the use of a case study this paper investigates the role of wetlands in low frequency floods, using the Rat River watershed in southeastern Manitoba as a representative watershed of the Red River basin. This investigation was accomplished through the use of the Hydrologic Engineering Centre’s Hydrologic Modelling System (HEC-HMS). Three scenarios, with increasing wetland areas, were run using data from 1997, and comparisons were made. Based on the results of this case study it was found that a reduction in total flood volume could be accomplished with an increase in wetland area. The results clearly show, however, that given a low frequency flooding event, this reduction in water volume is minimal, and that a reduction in the flood peak is non-existent.