This study developed a new snowdrift model to evaluate the snowdrift height around a snow fence, often installed along a road in a snowy and windy environment. The model consisted of the conventional computational fluid dynamics (CFD) solver by the Lattice Boltzmann method (LBM) and a module for snow particles’ motion and accumulation. The calculation domain was a half channel with a flat free-slip boundary on the top and a non-slip boundary on the bottom, imposing an inflow with artificially generated turbulence from one side to the other outlet side. Besides the reference experiment with no fence, the experiment was set up with a two-dimensional and a three-dimensional fences normal to the dominant wind direction in the channel center. The estimated wind flow over the two-dimensional fence was characterized by a swirling eddy in the cross-section, whereas the wind flow in the three-dimensional fence experiment was horizontally diffluent with a dipole vortex pair in the leeward of the fence. As a result, almost all of snowdrift was formed in the windward of the two-dimensional and three-dimensional fences, but it was also formed as the split streak in the leeward of the three-dimensional fence. The result suggested that the fence should be as long as possible to avoid the snowdrift on roads.