What can be a significant result of poor drainage system planning?

The significant result of poor drainage system planning is flooding and damage. Effective drainage systems are essential for managing stormwater and preventing water accumulation, which can lead to flooding. When a drainage system is poorly planned, it might not adequately handle the volume of water during heavy rains or storms. This can result in water pooling in certain areas, leading to surface flooding that can damage properties, roads, and infrastructure.

Additionally, flooding can cause long-term issues such as erosion and waterlogging, which can negatively impact the environment and surrounding ecosystems. It's important to design drainage systems that can efficiently channel water away from populated areas to minimize risk and protect both human activities and natural landscapes.