You should get a base weld. That is really the best way to ensure that water does not get into the wood core, which will quickly destroy your board.
The damage to your base has very little to do with the quality of the construction and a lot to do with sharp rocks being stronger than base materials. That board has a sintered base which in general is a denser, stronger base. Every board will come out of the situation you described with similar damage.
If you really want to avoid having that damage re-occur you will have to stop having fun in the powder and stick to groomers. Personally I think the reward of powder is well worth the risk of base damage.