I am concerned my core is not deep enough. The dam was just done about 4 weeks ago and we have not had any water since then, although it is slowing filling from a spring/underground stream. I want to make sure the spring/underground stream is not going to go under the dam. It would be nice to have an expert look at it before it starts to fill. Although I am not sure if there is any way to do any testing? Or maybe I should just wait and see if it fills all the way up.