Dave,
Thanks, you bring up some good points, I've herd horror stories about foundation issues here. Our house is a 2000 build, no automatic foundation watering system but we do keep driper hoses along the foundation and try to monitor the soil throughout the dry times. I haven't herd or seen of any settling issues in the neighborhood but that doesn't mean that they aren't there. A risk of messing with the foundation of our home isn't worth one hugel bed so we will adjust our plans, thanks again.