Proper Foundation Drainage

"Footing-drain problems are expensive to fix.  Building codes require perimeter drains around the outside of basement footings. They are not difficult to install properly before the foundation has been back-filled, but they are costly and disruptive to put in after the fact.  As long as you're going to protect the bottom of the foundation of a house from water, it's worth doing right." http://www.greenbuildingadvisor.com/green-basics/foundation-drains-0