We have a hillside that has a 30-35 degree slope. We have 2 sections, each ~60 feet across by ~40 feet vertical. We have an 8 foot wide concrete drainage swale between the 2 sections. We want to lay pipe in the diagram shown below, but are unsure how to dig the trenches for the vertical runs, horizontal runs, and boring a hole beneath the swale without doing it manually. We've looked at renting a ditch witch, but the smallest one we found is 900lbs, so going vertically up the hill or horizontal ...
