The government has published further guidance on getting and using Conservation Covenants, see link below. Conservation covenants are private, voluntary agreements between landowners and a “responsible” body for the purpose of delivering lasting conservation benefit for the public good. 

Conservation covenants help to achieve this by creating both positive and restrictive obligations in respect of the land. These obligations will then bind all subsequent landowners either until the specified term of the conservation covenant expires or in perpetuity. The idea behind these is to allow the requirement for a 10% Biodiversity Net Gain on all developments to work more easily.