This thesis details the work completed in order to develop a hydrodynamic and nitrate transport and reaction model for Round Lake, a backwater on UMR Pool 8. This work begins with investigating the fundamentals of nitrogen removal in aquatic ecosystems and reviewing other combined hydrodynamic and nutrient modeling efforts. Field data were gathered to determine model boundary conditions and provide a basis for calibration and validation. Using this data, the flow regime in Round Lake was simulated. CFD applications to model particle residence times and species transport and reaction were used to analyze the effects local hydraulics have on nitrogen removal in the lake. Results demonstrated an ability for CFD to predict spatial variation of nitrate with this ecosystem.