Awel y Môr Seabed Mobility and Scour Assessment

Working with RWE to improve understanding of the offshore wind farm's seabed mobility and scour potential

Sediment bedforms (such as sandwaves and megaripples) which actively migrate across the seabed have the potential to expose or bury seabed assets, affecting the risk profile for asset failure.

Natural seabed variability may also be exacerbated by localised scour around infrastructure placed on the seabed, potentially reducing the stability of structures if inadequately accounted for at the design stage.

RWE commissioned ABPmer to assess sediment mobility and scour potential at their Awel y Môr wind farm site, located in a highly dynamic area of seabed off the North Welsh coast.

The work was used to help support export cable route selection, as well as inform the ongoing wind turbine foundation, array and export cable design process.

Using a combination of project-specific geophysical data, recent and historic seabed surveys, and oceanographic data from our SEASTATES metocean database, we mapped the behavioural characteristics of the seabed across the wind farm site and export cable corridor.

High resolution hydrodynamic and sediment transport modelling were also used to map out the detail of long-term regional scale sediment transport pathways and linkages.

Detailed statistical analysis of large areas of high-resolution bathymetric data was undertaken to quantitatively assess the spatially varying dimensions of present day bedforms. The resulting maps (at 10m resolution across the whole project area) were used to further quantify potential future bed level variability, and as the basis for maps of the ‘non-mobile reference level’ to inform foundation design and cable burial design and risk assessment.

GIS-based statistical analysis of coastal mapping data (including LiDAR, topographic beach and nearshore bathymetry surveys) was also undertaken to consider the potential for coastal erosion and vertical change in beach levels at the landfall over the lifetime of the project. This information has been used to inform the landfall selection and design process.  

The wind farm is targeted to be fully operational by 2030.

A recognised Development Service Provider offering a wide range of services that support clients throughout renewable project lifecycles, ABPmer has provided input to most of the UK’s offshore wind developments, including technical input to engineering design that satisfies both consenting requirements and international standards.

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