Åkersvika consists of the deltas of the rivers Svartelva and Flakstadelva and the adjacent shallow basin forming their joint outlet into Lake Mjøsa. It is one of the largest and best developed classic freshwater delta systems in Norway, and its rivers upstream remain relatively unmodified. The reserve is one of the most important staging sites for wetland birds following inland migration routes in Norway; and a total of 226 bird species have been recorded. 15 species of fish also occur, including local forms of trout, grayling and lamprey which all spawn in the rivers.
Following the Ramsar Advisory Mission, new areas were added to compensate for areas excluded due to a road enlargement.