Biferno is the only river that flows entirely in Molise territory. It was formerly called Tifernus. It starts downstream of Fiumara Bridge, crosses Molise region, receives 45 tributaries and runs for 96 Km. Its hydrographic basin area is 1320 sq. Km.
Biferno river (in local dialect lu Bufiern or u’Bfiern) can be defined as torrential regimen, the floods are closely related to the raining regime, condition determined by different elements, such as tributaries coming directly from the valley slopes and poor permeability of the territory. The area includes the lower course of Biferno River characterized by a slow current and a large development of riparian vegetation. The habitat is an island of natural vegetation in a landscape consisting of large monocultures, inhabited centers, roads, landfills, quarries and industrial areas. The most prominent species of flowers is the willows and the poplars which give rise in some places to dense gallery forests, within which find refuge many species of birds. In addition, there are two species of reptiles of Community interest: Turtle of Water and Hermann’s Tortoise.
The area that goes from Cigno confluence to the area before the mouth of Biferno river is considered a Special Protection Zone, an area between river and marine environment, with the vegetational aspects that are the result of this kind of territory. The site, in particular, has a large number of habitat typical of the coastal environment that have a good level of conservation and representativity. It is an area for a considerable ornitofauna and the river environment, and it is also important for the ecology of Emis orbiculari.