An artificial wetland is a man-made approximation of a natural wetland habitat. These constructed wetlands are frequently employed as part of programs designed to restore natural wetland habitats and ecosystems. Additionally some artificial wetlands are further engineered so as to serve other purposes, often related to water or sewage filtration and treatment. Such engineered wetlands can often be a viable alternative to more industrial processes of water and waste treatment.
Humans have tended to eliminate wetlands as part of the process of development, a trend that extends back into antiquity. Wetlands are areas where the soil is naturally wet nearly all the time and where surface water is very common. The agricultural revolution in Europe saw a great decrease in the overall acreage of wetlands, as swamps, bogs, and fens were drained and turned into farmland. Similar practices have been widely employed in other regions in more recent years, to the detriment of the environment, and with unforeseen negative consequences for human populations.
Natural wetlands serve a variety of biological functions. They provide habitat for a diverse array of plant and animal species. These ecological niches have been at risk of disappearing entirely for decades. An artificial wetland is designed to mimic many of the characteristics of a natural wetland, and provides a home to many of the same species.
Recent research has shown that wetlands play an important role in ameliorating some types of environmental conditions. Wetlands naturally absorb and hold excess water that might otherwise lead to flooding. Coastal wetlands have been shown to play a crucial role in mitigating the impact of large storms. An artificial wetland can serve these functions in areas where the natural wetland has been reduced in size or eliminated.
An additional property of an artificial wetland is its ability to serve as a giant chemical reactor and filter. Through the careful selection of soils, gravels, and plant species, environmental engineers can tailor an artificial wetland to perform certain useful tasks. In areas where a great deal of fertilizer is used, for example, it can contaminate groundwater supplies. A carefully-planned artificial wetland can be constructed in such a fashion as to remove excess fertilizer from the water supply before it ever reaches a water treatment plant.
Water and sewage treatment plants themselves can be designed as artificial wetlands. Properly-constructed cascades of wetland plants and soils can serve as extremely efficient filtration systems. This type of artificial wetland has a positive impact on the environment both by supplying habitat and by minimizing pollution through non-industrial means.