The answer to 'why is my stone walkway drainage problems' is that there are several common causes, including poor initial installation, soil erosion, and clogged drainage systems. Symptoms may include standing water, uneven settling, and moss or algae growth.
To troubleshoot and fix the issue, first check for any cracks or gaps in the stones that could be allowing water to seep through. You may need to re-level or re-set the stones. Next, inspect the drainage system - look for clogged or damaged pipes, and ensure the walkway has proper slope and runoff. If the problem persists, it's best to call in a professional landscaper who can properly diagnose and address the root cause.