On 8th February 2021 a pair of beavers were released into a suitable enclosed site in west Dorset by the Wildlife Trust. The Wildlife trusts website says:
Beavers are often referred to as 'ecosystem engineers'. They make changes to their habitats, such as digging canal systems, damming water courses, and coppicing tree and shrub species, which create diverse wetlands. In turn these wetlands can bring enormous benefits to other species, such as otters, water shrews, water voles, birds, invertebrates (especially dragonflies) and breeding fish.
Beavers and the landscapes they generate benefit both people and wildlife because:
They help to reduce downstream flooding - the channels, dams and wetland habitats that beavers create hold back water and release it more slowly after heavy rain
They increase water retention
They clean water
They reduce siltation, which pollutes water
You can see more about the project here https://www.dorsetwildlifetrust.org.uk/BeaverProject
Planet Shaftesbury's contacts in Purbeck have arranged a presentation and Q&A about the project on zoom on Wednesday 24th February. Details accessible from the home page, prior to the event.