(Note: there are other things that are suboptimal about my garage, namely that it was built 100 years ago right on the property line and when it was rebuilt sometime later, it was allowed to stay there despite normally having a 5 foot setback requirement. As a result, this concrete block structure itself actually serves as part of the retaining wall and has moisture seepage issues from the uphill side. I actually think having the neighbor’s outbuilding covering that patch of land and managing the rainwater via my downspout helps the matter, because the ground between them gets no rainfall at all.)