We have a deck built over the top of our garage and the previous owners built a wall to make part of the deck indoors. The deck has a roof over the complete deck. The ground next to the wall that splits the inside and outside deck is soaking wet. I am not sure where the water is coming from. It seems the water on the outside of the deck is seeping under the wall into the house. How can I stop this without taking down the wall?

How deep is the soil on the outside of that wall?

The leak is coming from the top of the garage into the house. It is not from the ground. We live on a granite hill and the house is tiered into the hill. The garage is on ground level then the house is on the next level up into the mountain with the floor of the front of the house sitting on top of the garage. That is where the water is coming from.