Abstract: This paper presents a three-dimensional hydrodynamic model.The bottom friction has used quadratic expression of velocity.In the treatment of vertical turbulent coefficients,the parameterization scheme has been employed with Richardson numbers.A vertical compressed coordinates(σ) was used.With splitting mode technique and alternating direction implicit(ADI)algorithm,the external model is derived by vertically-integrating the momentum equations to solve the change in water surface which feedback the internal model and solve the vertical velocities.Hence this algorithm scheme can save computing time significantly,therefore,this model can be used in deep and small water body,as well as thermocline lakes/reservoirs.Finally,as a example of its application,this model was applied in East Canyon reservoir,Utah,USA.The efficiency of the prediction of thermocline corresponding to the wind forcings and inflow and outflow has been discussed.