The Site is among the most important freshwater deltas in Norway, and features small lakes including oxbow lakes, channels, newly developing sand islands and river courses, and adjacent mires. The different areas of the Site feature diverse vegetation, from sandbanks with pioneer vegetation, to sloughs with reed vegetation, wet and flooded alder forests, and other deciduous and coniferous forests. There are also smaller areas of agricultural land. The Site is an important inland breeding area for waterbirds such as the spotted crake Porzana porzana, the greater scaup Aythya marila and the water rail Rallus aquaticus, which are all listed as threatened on the Norwegian Red List. It plays a key role for migrating birds, especially as a staging area during spring migration. The numerous river branches are particularly important for ducks, while the swamps and mires are most important for waders. In total 150 bird species have been recorded, while about 20 species of mammals are present, including the Eurasian otter Lutra lutra and the lynx. The area recharges local groundwater reserves through abundant caves and underground rivers. The Site is used for recreation activities such as sport fishing, birdwatching, canoeing and hunting.