Water is a very important element in Permaculture design. Water systems can achieve greater overall protein production per square metre of water surface than the same area in land systems. Ponds are freshwater ecosystems that can be tremendously useful in permaculture practice.
They can provide food, medicine, water storage, sun reflection (heat and light), filtration for waste, recreation and aesthetic value. A variety of edible species of plants can be grown in and around the margins of a pond, depending on the local climate. Even small ponds can produce a steady supply of edible foods such as watercress, water chestnuts, taro and water spinach (kang kong). However parasites and pathogens also have part of their life cycle in water, so plant stocks must be healthy, and disease free. Ponds attracting wildlife such as frogs are often a good indicator of the quality of a waterway. Many different edible fish species can be raised in a pond. If properly managed, a pond can also produce a great deal of food and materials which can be sold or bartered to create income. An alternative to ponds is the bog garden where a wet area can be developed.