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A high-resolution three-dimensional hydrodynamic model (AEM3D) was developed for Lake Taupō using a 200 m grid and forced with hourly meteorology from the New Zealand Reanalysis (NZRA; 1.5 km), for 2001–2004. The model was evaluated against temperature and current measurements and reproduces the observed thermal structure and current variability, including near-inertial oscillations. During stratified periods, results showed a persistent anticlockwise gyre in the central basin, consistent with anticyclonic inertial or Poincaré-type motions at this latitude. In addition, a coherent clockwise nearshore circulation occurred within approximately 4 km of the shoreline, consistent with coastally trapped internal Kelvin wave dynamics, with a characteristic timescale of approximately three days. These physical processes were accompanied by strong vertical and horizontal redistribution of chlorophyll-a, indicating that lake-scale circulation directly influences biological processes. A passive-tracer simulation for the February–March 2004 Tongariro River flood reproduced the observed transient gyre-like sediment-plume structure, indicating a wind-driven, episodic feature shaped by evolving wind stress and shoreline-bathymetry interactions. These results advance understanding of large-scale transport and mixing in Lake Taupō and provide rare insight into Coriolis-influenced dynamics in a large Southern Hemisphere lake.