La Mancha Wetlands (Humedales de la Mancha in Spanish) are situated in the district of Castilla - La Mancha in Spain. The wetlands cover an area of 40 sq. km and consist of 27 wetlands (La Mancha Wetlands Nature 2000 sites), 15 wetlands in the Ruidera Natural Park and one wetland in the Daimiel National Park.
The water of the wetlands partly has drinking water quality, but may also be saline or hyper saline, the electrical conductivity ranges from 500 to 50,000 µS/cm. The wetlands are shallow lakes, with a depth between 1.5 to 2 meters. Only the wetlands in the Ruidera Natural Park are 20 meters deep.
La Mancha Wetlands form a unique habitat for highly specialised flora and fauna. Some endemic species are threatened, such as Helianthemum polygonoides. Many migratory birds winter in the wetlands, such as Eurasian Teal (Anas crecca), Eurasian Wigeon (Anas penelope), Gadwall (Anas strepera), Northern Shoveler (Anas clypeata), White-headed Duck (Oxyura leucocephala), Great Bittern (Botaurus stellaris) and Black-necked Grebe (Podiceps nigricollis).
The wetlands are surrounded by Mediterranean forest, seasonal grasslands and fields (cereal, vineyards and olive trees). These farming activities have the greatest negative impacts on the groundwater and wetland conservation. For the irrigation of the fields, an immense amount of water is withdrawn. Also the use of nitrate and phosphate has very negative impacts on the wetlands biology.
In 1980, the UNESCO has declared the La Mancha Wetlands as Biosphere Reserve, because of its importance for the waterfowl and its rich bio-diversity. This wetland complex is one of the species-richest wetlands in Western Europe.