There are already many suitable sites capable of sustaining beaver in Wales, and elsewhere in the British Isles.
Territory for a beaver family averages 3.5 kms of riverbank, varying according to abundance of food source.
Beaver prefer living in burrows in banks along slower flowing, unpolluted rivers with good aquatic vegetation and adjacent mixed woodland.
Contrary to popular belief, beaver prefer not to build dams. These are hard work and usually constructed later in the dispersal process when better quality habitat, which does not require damming, is already occupied and remaining waterside habitat is unsuitable for burrows.
Dams may thus not become a landscape feature for some years after reintroduction.
They are created from branches, piled across shallower streams, and usually less than 3 metres in length and up to 1 metre in height.
Such dams are frequently breached by floodwaters and have not been found to create a barrier for anadromous fish species such as sea trout and Atlantic salmon.
Least favourable territory, generally of faster moving streams in upland areas, is the last to be colonized.
“Lodges” are built in the dam ponds to provide shelter.
These consist of a structure of branches heaped up to 8 feet above the surface, with an underwater entrance to the living quarters – generally twin chambers – at its base.