Hydro turbines have complex non-linear dynamics, especially in the presence of large or abrupt load disturbances. In this work, the implementation of a weighted multiple model adaptive control (WMMAC) scheme on a hydro turbine plant was studied. To ensure stability, the system was designed in accordance with the virtual equivalence system and adaptive mixing control criteria. Four candidate linear estimator models were chosen representing 25%, 50%, 75% and 100% load conditions. For each candidate estimator model, a compensator was designed to meet performance requirements under the corresponding candidate load conditions. The performance of three different control structures; the H ∞ , LQG/LTR and PI controllers, used in the WMMAC scheme, were simulated under abruptly changing and smoothly varying load conditions. To account for the transients before reaching synchronous speed, in the first 50 seconds, a no-load compensator was used. From the results, the PI controller produced the best performance.