Groundwater-dependent ecosystems (GDEs) include valuable ecosystems such as springs, wetlands, rivers, lakes and lagoons. GDEs and associated aquatic ecosystems are important to protect as they provide many ecosystem services. A few GDEs such as some wetlands, are important as habitats for migratory birds or rare plant and invertebrate species, and are protected by international, local agreements and legislation. 

GDE comprise a large variety of ecosystems that are found in different hydrogeological, climatic and geographical settings from headwaters to coastal lagoons. Groundwater flow paths differ between the systems; some receive recent water whereas others are fed by water with a long transit time or even sea water, influencing geochemistry and temperature variations in water. 

Human activities threaten GDEs by disturbing habitats, depleting groundwater reserves, as well as altering groundwater regime. Globally, GDEs are being threatened by groundwater depletion due to increasing water demands from growing populations and increased industrial demand. Human activities have impacted GDE habitats through vegetation clearing, filling or draining of wetlands and alteration of surface water courses.