Amongst my ancestors I have a Van de(n) Waterloop family which lived (mainly) in Okegem and also in Pamel.
To the best of my knowledge, this family name no longer exists in Belgium.
In the genealogical records I have seen, one finds the name in the XVIIth and XVIIIth century, and then it disappears. There cannot have been too many branches in the family. Maybe there were too many girls and too many unmarried sons ?
Still, thousands upon thousands of people may descend from that family, just as I do.
Research on Geneanet indicates that the name was known (almost) exclusively in the immediate surroundings of Okegem and in parts of the Nord - Pas de Calais in Northern France, but there it was mostly Waterloop (without Van de).
I do not have the time to try to find the descendancy of the few family heads with that name, but if anyone, anyone at all, does know more about it, I would be pleased to hear about it on firstname.lastname@example.org.