It has something to do with bump mapping. Looks like it's not implemented correctly in 10th Anniversary Mod. It's the effect that makes Arokh and water in-game look beautiful. Turn bump mapping off in Riot Engine options and the glitches will go away but turning off stock effects really defeats the purpose of a graphical mod.
"Once a profound truth has been seen, it cannot be 'unseen'. There's no 'going back' to the person you were. Even if such a possibility did exist... why would you want to?" - Dave Sim