Romania's water resources, being formed of surface waters – inland rivers, lakes and reservoirs, the Danube River – and groundwater are relatively poor and unequally distributed in time and space.
The Danube Delta, where the river flows into the Black Sea, is an ecological system unique in Europe. Its ecological value is inestimable.
It covers an area of about 550,000 hectares of Romanian territory, with a hydrological network including main branches, secondary branches, channels and lakes. It contains a wide variety of species of plants, fish and birds, most of which are migratory.
Because of this biodiversity the whole zone has been declared a protected area and a World Natural Heritage Site.