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.

Good beaver territory.This patch has been used continuously for 30 years -
note the big trees, notably the conifers, left untouched. There are normally
no dams in such habitat.[Photo courtesy Duncan Halley]

Beaver prefer living in burrows in banks along slower flowing, unpolluted rivers with good aquatic vegetation and adjacent mixed woodland.

Good territory for food supply, but with faster water. It is thus colonised later
on, though only the banks are used. Note the buildings in the background -
beaver adapt to neo-urban living.[Photo courtesy Duncan Halley]

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.

Quite good territory, but requires damming so it is occupied later still.
[Photo courtesy Duncan Halley]

Least favourable territory, generally of faster moving streams in upland areas, is the last to be colonized.

Lower priority territory - shallow, steep streams with high velocity. In more
Northerly latitudes it is frequently iced over in winter.
[Photo courtesy Duncan Halley]

"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.

Beaver lodge photo by Brad Harrison