OK guys this is a wash-out from a clogged up rain gutter that happened when this place was being rented out.He has existing railroad ties 2 courses along the lawn there and this corner your looking at is the corner foundation of his deck. He wants some type of retaining wall...But just in the corner not along the whole thing. The water was going where the renter poured that cement and also under the deck and erroding behind the foundation corner. On the other side of the RR ties it goes very steep down the hill. How would you fix this?The rain gutter situation is fixed so water won't be pouring in the corner like it was.