The reservoir is an important site for breeding waterbirds such as great crested grebe, gadwall, shoveler, common pochard, tufted duck and common tern. At one stage, the reservoir was second only to Rutland Water for the most breeding pairs of great crested grebe in the UK. Other breeding birds include eight species of warbler. In 2008, the first nesting attempt by great cormorant took place as well as the first nesting attempt by grey heron for several years. Neither attempt was successful, but grey heron have bred successfully since 2017.