Swimming

Is it allowed to swim in the water on the terrain?

Yes you can swim in the pond that has Griet Titulair island in it, and in the harbor or at the beach near Engelbart field.

The other ponds are not for swimming because of the terrains irrigation system that is in those ponds (tube's and such)

Be careful when swimming out of the harbor or the Engelbart beach: the canal is a major shipping route, very wide, very cold, very deep and has strong currents. Do NOT overestimate your swimming ability here.