A common problem in basements in the western part of The Netherlands, is that when the underground water level rises, your basement is flooded. What to do? You can buy a water pump but you can also seal it…. There are companies specialized in this procedure. They drill holes in a grid pattern in the ground and on the walls up to 1 meter high, and then they fill the holes with a special jelly product which will prevent the water to infiltrate your basement.