in an area that will not allow basements because of unstable soils. but I would think that gutters and proper over hangs and mound up soil against the foundations will surely help, but I do not think that it will cure it. Soils against the foundation need to be watered in. Meaning adding soil and water or melt it in and add more and do the same. Your home ideally should be built on its own hill of sorts so that the water will drain or "fall" away from the foundation in ALL directions. Overhangs must be a good distance away from the foundation, gutters downspouts should be able to carry the water a good distance from the foundation. So many variables to consider.
What I would be doing as Jay would state, be prepared to document all occurances via camera, written words, visits from the builder and all other coms. I would definately have a pump installed regardless because with Spring rains, all basements leak to an extent. This would just be a wise investment.