We studied the effect of potential future climate change on floods, flood protection, and electricity infrastructure in the Conasauga River watershed in the US using ensemble hydrodynamic modeling. We used a GPU-accelerated Two-dimensional Runoff Inundation Toolkit for Operational Needs (TRITON) hydrodynamic model to simulate floods. Overall, this study demonstrates how a fast hydrodynamic model can enhance flood frequency maps and vulnerability assessment under changing climatic conditions.