I searched previous threads and did not see anything that was exactly similar to my situation.
I am going to do my best to paint the picture here.
We have a cabin that is cement pillar and beam construction built on a slope. The land slopes down towards the lake. We just had the open crawl space area under the house enclosed to provide additonal storage. There was an existing retaining wall on the lakeside (downslope side) of the house. it was falling apart. We replaced it with a much more substantial retaining wall made of 6X6 green treated timber. It runs about 35 feet in length. The top surface of the wall on the left end it is probably about two feet above grade and on the right end it is about 4.5 feet above grade (the land also slopes left to right). The wall is level all the way across. It is about 4 feet from the house to the front edge of the wall. This retaining wall sits right below a deck attached to the house directly above. We had some very substantial rains last weekend and I noticed that the water is now ponding in the dirt behind the wall. We had probably about 3 inches of standing water at one time. It seems to dissipate quickly but I am not comfortable with that much water.
I'd like to install a french drain the entire length of the reataining wall but have never done anything like this. I am envisioning sloping it from left to right to follow the contour of the land. So it would be capped on the left end and then i would basically cut a hole in the 4.5 foot end (right end) of the wall and have the pipe stick out that hole and drain tat that end.
I would love to get some pointers if you have any suggestions? How deep should the drain tile be? I can only go down about 2 feet on the left end. Is a 4 inch tile proper? This cabin is in the middle of the woods so drilling a hole in one end of the timber wall is fine as no one will ever see it. What is the best way to drill this hole? Hole saw?
I am probably not asking the right questions but would appreciate any help or tips.