Flemish is a Germanic language and so related to English, Dutch, German, and Friesian so it's not surprising they use groeve as the word for a mine or excavation. A proto-germanic word for digging will have given rise to the modern english grave, groove, grub (as in to grub out something) and grove in the old sense of a mine, likewise the german verb gruben and this flemish word. Linguistic history lesson over..... ๐
Follow the horses, Johnny my laddie, follow the horses canny lad-oh!