Would there have been an underground stream in that area that used to help feed Groat?
But yes, water table and soil composition certainly impact things.
Hydrostatic pressure is a real concern for these kinds of structures/foundations and so additional waterproofing and an enhanced weeping system will be required. Often times if it is sandy, soil infiltration can be a real problem for these systems and reduce their performance by 40-50% which further compounds the problems.