*WINNER* Development of HEC-HMS Model for the Cane Creek Watershed

Abstract

Cane Creek Watershed project was aimed at developing a Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS) model for the Cane Creek Watershed to understand its hydrological characteristics and then to simulate 10-yr, 50-yr, 100-yr, and 500-yr storm events. Discharges from past events were converted from depth gauge data and used as observed flow to calibrate the model. Flows used include that of October 23rd, 2017, May 31st, 2018, June 26th, 2018, and July 21st, 2018, since these events represented different flow regimes between 2017 and 2018. Data used in constructing the HEC-HMS model including land-use/land-cover data (LULC), digital elevation models (DEM), and precipitation depth data. Once the model was calibrated and validated Soil Conservation Service (SCS) design storms were simulated and their peak flows were obtained. The performance of the model was evaluated using the statistical techniques Nash–Sutcliffe Efficiency (NSE), Root Mean Square Error (RMSE), Percent Bias (PBIAS), Coefficient of determination (R2), and Ratio of the RMSE to Standard Deviation (RSR). When run with 10-yr, 50-yr, 100-yr, and 500-yr storm events the calibrated and validated model yielded a discharge of 2538-cfs, 3942-cfs, 4744-cfs, and 6285-cfs respectively. While plausible, these discharges’ reliability are called into question by statistical analyses, which were mixed in affirming the model's accuracy. This may be as a result of the model's exclusion of the Cane Creek Reservoir and the changing geomorphology of creek crossing 1(where the observed flow data was collected).