Walney Extension Offshore Windfarm and Burbo Bank Extension Offshore Windfarm

When DONG (Danish Oil and Natural Gas) Energy wanted to build two offshore windfarms – one off the coast of Walney in Morecambe Bay, the other at Burbo Bank in Liverpool Bay – OA North was called in to investigate at the sites where the schemes made landfall.

An evaluation along the onshore export cable route of Burbo Bank Extension Offshore Windfarm, which extends inland from the coast of north Wales near Prestatyn to a substation at Bodelwyddan, uncovered pits, ditches, gullies and other evidence of a prehistoric settlement. Burnt material from some of the features were radiocarbon dated to the early to middle Bronze Age. The remnants of field ditches further along the route were of early medieval date and appeared to form part of a system of drainage ditches leading to the River Clwyd.

At the site of an electricity substation for Walney Extension Offshore Windfarm near Heysham, Lancashire, the evaluation uncovered a sequence of peat and marine flood deposits and the potential remains of late prehistoric or Roman settlement. On further investigation, however, these features were shown to be natural elements of a system of palaeochannels associated with the wetland environment.

While the archaeology was not spectacular, our work has improved our understanding of these coastal areas, and allowed DONG Energy to proceed with the construction of its windfarms. It also demonstrated that even offshore schemes have onshore impacts.

Image: David Dixon [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons