akil gave you good basic advice. I would simply add to be careful where you divert the water to. Most state water codes require that water, when concentrated in a pipe or channel, be taken to a "recognized drainage course". Lawyers get rich on determining what a reconized drainage course is. Try to keep the water going to the same place it went to before your construction took place or you may find yourself in court with a neighbor who discovers that he has more runoff water than before. If you can keep the water in "sheet flow" rather than concentrated, so much the better.