Yes, outdoor plumbing fixtures can be affected by soil erosion or shifting. Soil erosion, caused by factors such as heavy rainfall or improper grading, can expose and damage underground pipes, leading to leaks or breakages. Additionally, soil shifting due to settling or ground movement can put pressure on plumbing fixtures, causing them to shift or become misaligned. Regular inspection of outdoor plumbing systems, along with proper landscaping and drainage solutions, can help mitigate the risks associated with soil erosion and shifting.