Tsunamis happen every year in the seas and the oceans throughout the world. These tidal waves propagate at high speeds and in various directions and, if they reach the shoreline, tremendous damage can occur to these areas as well as their structures and facilities. Therefore, understanding this complex phenomenon and predicting its behavior can mitigate such damages. In the present study, the Lattice-Boltzmann method (LBM) is utilized to simulate the phenomenon of wave formation in a tank. Considering seawater as viscous flow, the governing Navier-Stokes equations for shallow water along with the LBM is used to simulate water level. Wave generation is also created by simulating a tank that flushes its left wall and does it once again. The obtained results show small waves at early times which become more intense over time. Besides, the pressure at the end of the tank is at maximum and it consequently decreases as moves upwards. This reveals that hydrostatic pressure variations are due to fluid’s height. In addition, the effect of shaking sidewall angles on the waves is investigated. The simulation results demonstrate a significant rising trend in wave height attributable to angularization of the sidewall. Moreover, by 30o oblique, wave production amplifies but no change is observed in the wave height at distant points from the slope.