The phrase "ancient flood protection" refers to methods that people in the past used to prevent or mitigate flood damage. Synonyms for "ancient flood protection" include historical flood prevention, traditional flood control, vintage flood defense, and historic flood mitigation. These phrases describe methods that were used before modern flood control methods were developed. Examples of ancient flood protection include building levees, diverting water, constructing drainage systems, and creating artificial water channels. While some of these methods may no longer be effective in modern times, they provide a glimpse into how people have tried to manage and overcome one of nature's most destructive forces for centuries.