Until 2015, The Crown Estate's offshore wind customers were required to provide onshore survey data relating to their offshore Lease areas. Onshore survey data includes any surveys that exclusively collect data related to the landward area of the project, for example the onshore cable corridor.

Whilst The Crown Estate no longer require customers to provide their survey data relating to onshore survey works, offshore developers are still collecting extensive amounts of data to understand the impact of onshore cables and substations on the environment and local communities.

Onshore surveys typically include visual impact assessments relating to the onshore infrastructure, surveys to understand habitats and species, and occasional geophysical and geotechnical studies.

Relating to onshore survey data that the MDE holds prior to 2015, most of the survey data relates to sensitive species, such as great crested newt, and as a result cannot be published.