Advising North Wales tidal energy lagoon

Environmental and planning advice for a proposed tidal lagoon in the outer Dee Estuary

Mostyn SeaPower, a subsidiary of The Port of Mostyn, has developed proposals for a tidal lagoon in the outer Dee Estuary. The design includes a 6.7 km boundary wall extending from the Port of Mostyn to the Point of Ayr at the estuary mouth.

In developing this proposal, Mostyn SeaPower has recognised its potential to deliver multiple objectives. It will produce enough low-carbon electricity to power 82,000 homes in North Wales. It will create 300 jobs during the construction period as well as permanent jobs during its operational phase. It will also provide flood protection to a hinterland that includes homes and businesses as well as the A548 Coast Road and the North Wales coast railway line.

ABPmer, as a long-standing adviser to the Port of Mostyn, provided environmental and planning advice for this proposal. During the early stages of its development, we prepared a detailed environmental feasibility study and a survey plan. We then consulted with regulators (especially NRW) to develop a survey strategy. This strategy is required to ensure there is a robust evidence-base underpinning the necessary planning and marine licence applications and the detailed impact assessments that will need to accompany them.

The Dee is an area of high nature conservation value. It is important therefore, that detailed information is obtained to describe the baseline ecological conditions and understand the changes that will occur as a result of constructing the proposed lagoon.

To underpin the assessment, ABPmer carried out bespoke survey of the wave and tidal conditions in the Dee Estuary and used the results to develop a high-quality hydrodynamic model of the Dee Estuary. We also carried out two years’ of monthly ornithological surveys to describe how the lagoon area is used by waterbirds.