The answer to 'drainage system has weeds' is that weeds growing in your drainage system are a common problem that can indicate issues with your landscape drainage. Weeds may take root in areas where water collects or where there is poor soil drainage, clogging the system and preventing proper water flow.
Some common causes include inadequate slope or grading, damaged or blocked drainage pipes, and buildup of organic matter. Symptoms may include standing water, wet or soggy soil, and visible weed growth. To address this, you'll want to inspect the drainage system, clear any blockages, and consider improving the overall drainage design if needed. In some cases, calling a professional landscaper may be the best solution, especially for more complex drainage issues.