The answer to 'drainage system not growing' is that a non-functioning drainage system can be caused by several factors, including soil compaction, clogged pipes, or lack of maintenance. Symptoms may include standing water, poor plant growth, and even foundation issues.
To address this problem, you'll first want to inspect the drainage system for any obvious clogs or blockages. Try flushing the pipes with a hose to clear out debris. If that doesn't work, you may need to use a plumber's snake or have the pipes professionally cleaned. Improving soil aeration and adding organic matter can also help promote better drainage and plant growth. However, if the issue persists or you suspect a more serious problem with the drainage system, it's best to call in a professional landscaper or drainage specialist to diagnose and repair the issue.