Dredging project at Randers Harbour has now been completed. The sailing trench’s desired seven metre depth has thus been re-established.
Høj Nordic Marine Contractor commenced the dredging operation at Randers Harbour in July 2022 by surveying the sea bed. The survey revealed that an estimated approx. 180,000M3 would need to be excavated. The actual dredging operation ended up being somewhat larger, requiring a total volume of 220.000 m3 to be moved, as measured in the vessels’ holds.
The project involved dredging the entire harbour, Randers Fjord and the “bar” at the outlet of the fjord to a sailing trench depth of seven metres. Dredging work was also carried out at the same time in three local marinas: Dronningborg, Uggelhuse and Mellerup.
Up to four vessels and a pumping station were deployed
During the period, up to three or four vessels and a pumping station would all be at work at the same time. The pumping station pumped most of the excavated volume into three different onshore flushing fields along the coast of the inner fjord. On the days when multiple vessels were operating simultaneously, volumes of up to approx. 4,500 m³ would be pumped on a daily basis. Approx. 55,000m³ was also moved to take advantage of and fill the fascines along the fjord. The correct placement of the excavated material was ensured in collaboration with the harbour’s employees.
During the project, the material was pumped approx. 3-400 meters inland from the fjord. The material is transported in 50-60 cm diameter pump lines after the pumping station has mixed the material from the sea bed with water into a kind of mud mixture that is fluid enough to be pumped. As the dredging proceeds, the excavation is checked by performing another survey to ensure that the excavations are correct and that what needs to be excavated has actually been excavated. An “outsurvey” is then produced to serve as documentation for the work that has been done, so that the customer can see that the task has been completed.
The harbour is important to the region’s economy and employment
The harbour is of significant importance to the region’s economy and employment in Randers Municipality, as demonstrated in a catchment area analysis carried out by the University of Southern Denmark and the Center for Regional and Tourism Research for Danish Ports (the trade association for Danish commercial ports). The harbour generates an added value of DKK 1,173 million, which corresponds to almost 6% of the total added value in Randers Municipality and as the basis for DKK 366 million in tax revenue (business revenue taxes, VAT etc. to the municipality, i.e. 3.4 percent of Randers Municipality’s total tax revenue).
Randers Harbour undergoes a dredging operation of the harbour and fjord approximately every five years, to maintain the desired sailing trench depth. We are proud to have been part of this process.