Factsheet – Creating a High Resolution Hydrologic Model for Simulating and Forecasting Floods in the Wabash River Basin

Indiana is one of the most flood-prone states in the country, experiencing major floods in different parts of the state almost every year from both excessive rain and rapid snowmelt. From February to April 2018, more than 20 counties in Indiana experienced extreme flooding and were declared disaster areas by the Governor’s Office. The impacts of climate change and land development and urbanization is expected to exacerbate both the severity and frequency of extreme flooding in the region. This project has developed a large-scale hydrologic and hydraulic model capable of providing detailed flood information across the Wabash River Basin. Comparison of model results with FEMA generated flood maps demonstrates the model’s ability to generate dynamic flood maps which can be used for both flood warning and long-term planning. The model performance has been validated against USGS gage measurements. The overall performance of the model is reasonable considering its scale. Additionally, two smaller models were created for the Upper Wabash Basin and the White River Basin encompassing the city of Indianapolis to explore techniques for further improving model performance. Flood simulations from the smaller models have demonstrated the effectiveness of the developed framework in creating locally relevant large-scale flood models capable of providing street level flooding information.