I live in an area that is a water shed. Will this grow in a, sometimes, wet soil?
Pampas grass tolerates moist soil but being native to South Africa, it isn't adapted to wet soil. So it will be a matter of how many days it is in wet soil. You should also know that pampas is considered invasive in western Florida, Texas, Louisiana, California and parts of Oregon and Washington. This means it has been found growing where it wasn't intentionally planted and displacing native plants which birds and other native fauna depend on.