Can you help me decide between a foundation, slab on grade and crawlspace?
...a risk of highwater tables and if you are building on or near a floodplain. A slab would for sure be the safest route, since crawlspaces also invite the same risks of water infiltration, and they add cost for very little benefit. Here is a page that cover that very topic, have a look -
Crawlspaces or Slab Foundations ...