Possible retaining wall? Need some help with an issue in my backyard. Because of the slope, I get significant amounts of rain runoff from the neighbor into my yard where I drew the arrow. I’m thinking of building a retaining wall to help that and this area right here is kind of a disaster anyhow. Any recommendations on what to do to improve this? Originally by u/jittery-joe on Reddit: https://tinyurl.com/2cw96wok