What are you trying to accomplish? (i.e. "Why the question?")
Be advised that you are asking about a pretty complicated topic here - not just structural issues, but geotechnical and hydrologic as well. Not an area for the "weekend warrior" or casual designer.
For example, the depth of embedment - and type of material used - for piles may well hinge on the anticipated depth of scour. There are a good many structures in Florida that have suffered significant damage because the designer(s) failed to properly account for scour in their design.
Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora. See faq158-922 for recommendations regarding the question, "How Do You Evaluate Fill Settlement Beneath Structures?"