Well, you can always treat this as a high-poly model, then bake the normal map onto a low poly model, that's how it's usually done unless you use a sculpting solution. That way you get rid of all the excess polygons and minute detail geometry AND you don't get to spend two years UV mapping every little quad on the high-poly version. And the look remains pretty much the same.
P.S. Not sure what adding holes in piers has to do with bump-mapping, can you elaborate?