The area was mucky at the time, but once it dries out it becomes almost like concrete. I have little doubt Joran knew it would fill up with water covering the area. The only problem he would have is if it filled up with water too soon after burying Natalee, then the body would float to the surface.
Maybe I have gotten so cynical with all this but I do not believe they will find anything. Either in this lake or in the landfill. I just don't believe she will be found, ever.
On Greta's show tonight, the Aruban lawyer Lincoln said the the pond is in an area of a new park (still under construction). Would Joran or his father know when new concrete was to be poured in that area? Just wondering out loud.