Which aspect is crucial for preventing pool flooding during heavy rains?

Proper drainage systems are essential for preventing pool flooding during heavy rains. These systems play a vital role in managing excess water effectively. When rainfall occurs, a well-designed drainage system directs the water away from the pool area, reducing the risk of overflow and flooding. This includes features like gutters, drains, and grading that help channel water away safely.

While skimmers, pool covers, and increased wall height can contribute to general pool maintenance and safety, they do not directly address the issue of managing heavy rainfall. Skimmers help remove debris and surface contaminants, but they are not designed to handle large volumes of excess water. Pool covers can prevent debris from entering the pool but have limited effectiveness against significant rain accumulation. Increasing wall height may provide some protection against overflow, yet it does not tackle the underlying issue of water drainage and management. Thus, a proper drainage system remains the most effective measure to avoid flooding during heavy rains.