Background
Race Bank offshore wind farm is an internationally financed project off the Norfolk coast in the UK. Consisting of 91 turbines, the wind farm can generate 573 MW of green electricity, powering almost half a million homes. It is a positive step towards delivering the UK’s decarbonised energy system of the future.
To link the wind farm to an onshore substation, two offshore export cables were laid across salt marsh in The Wash. Salt marshes are home to rare and valuable species. They are vital global carbon sinks and protect coastal areas from erosion. The Wash is one of the largest protected estuarine sites in the country, internationally and nationally designated as a site of great importance. It is a Special Area of Conservation, a Site of Special Scientific Interest, a Special Protection Area and a Ramsar site.
Scope of services
To facilitate installing cables, we designed pre- and post-construction monitoring surveys and restoration proposals. The multifaceted work included
- annual botanical monitoring: surveying the vegetation and structure of the salt marsh in strategic locations along the cable routes, using quadrat sampling along transects. Our botanists conducted monitoring and national vegetation classification surveys, which we designed in consultation with Natural England, following the JNCC Common Standards Monitoring approach.
- developing proposals for mudflat and salt marsh restoration.
The restoration proposals were designed by our botanical experts, who collaborated with our habitat creation specialists in RSK Habitat Management to implement the plans. The proposals detailed the methods for restoration of the impacted areas. This included creating silt-traps, reducing water-pooling and planting locally sourced plant plugs. These are now helping to re-establish natural vegetation in the areas of bare mud created by the works and helped to reduce the size of one impacted area by more than half in a single year. The results from a range of experimental measures are being used to inform further remediation.
“RSK’s ability to provide a turnkey approach was of huge value on this sensitive restoration project. The work was carried out efficiently, effectively and safely. There were no complaints from the regulator or local stakeholders. We look forward to these effects helping to successfully restore the salt marsh.”