Swale is a type of low-lying area or depression that can collect water, often found in agricultural landscapes. It is designed to manage water runoff and can help prevent soil erosion. Swales are typically shaped like shallow ditches and can be planted with vegetation to enhance their effectiveness in filtering pollutants. In addition to their environmental benefits, swales can also support biodiversity by providing habitats for various plants and animals. They are often used in sustainable landscaping and are part of permaculture practices, which aim to create self-sustaining ecosystems.