Belgian company GEOxyz has been selected by TenneT to carry out geophysical and geotechnical surveys for the export cable route for the Nederwiek 3 Offshore Wind Farm (NW3) in The Netherlands.
The Dutch Ministry of Economic Affairs and Climate and TenneT TSO B.V. (TenneT) are planning an underground high-voltage connection from the Nederwiek OWF in the North Sea to the municipality of Geertruidenberg or Moerdijk.
TenneT awarded GEOxyz the geophysical and geotechnical route survey for the inland section in lake and riverine environments from Stellendam to Geertruidenberg and optionally the offshore section near the Nederwiek OWF and the nearshore realm south of the Port of Rotterdam. As a company having strong inland, nearshore and offshore capabilities, GEOxyz proved to provide the best quality proposal within the client’s budget and time limits.
Over the wide variety of environmental conditions, GEOxyz has mobilized the Geosurveyor VIII and Geosurveyor V for the inland and nearshore sections. For the offshore works, the Geo Ocean III or Geo Ocean VI are scheduled. Ultra shallow waters and land sections will be covered by our Geodrone ASV and aerial UAV team. Operating our specialized fleet of owned survey vessels gives us the flexibility to comply with the survey area complexity, as well as with the required permits for legislation.
Further specific aspects to the project, are the required 10 m penetration depth for geotechnical sampling. We introduced a novel technique in the marine environment to acquire high quality samples. The potential presence of unexploded ordnance, including suspected presence of aluminium sea mines, is a risk aspect our company is highly capable of dealing with through our in-house UXO consultant.
The aim of the surveys is to investigate the suitability of the envisaged cable corridor, establish the topography of the seabed and to identify obstructions in the corridor. Based on the acquired data, a geological model of the cable corridor and a resulting Burial Assessment Study (IBAS) will be supplied. This study shall determine the necessary technical parameters for cable design and installation methodology, thereby minimizing the risk of encountering unforeseen ground conditions during the cable installation process.