Ashful
Minister of Fire
Most of our pallets 'round here are made of white or red oak. The white oak ones can last quite a while in those conditions. Red oak... not so much.I wouldn't expect your foundation pallets to last too long, sitting right on the ground like that in an area subject to flooding. They will rot pretty quick. I think I would have stuck with the block plan - but it does look good.
If they're pine pallets, you'll be replacing them every third year.