Hollandsch Diep

Creating a dredging spoil disposal site with 20 years of storage capacity

Our client
The Dutch rivers Rhine and Meuse contain polluted soil. This is the result of illegal dumping by people and businesses over the course of many years. The Dutch Department of Public Works wants to dredge the soil and store it in a safe place. To this end, it awards a contract for the creation of a dredging storage depot in the river Hollandsch Diep to the Sassenplaat Consortium, of which Van Oord is a member.

Our work
The consortium began working on the design for the dredging spoil disposal site in December 2005. The partners spent the next two and a half years digging the site - which is 1,300 m long and 500 m wide - next to Sassenplaat Island, a nature reserve. They also constructed levees and grounds for facilities. In addition to the site construction, the project involved expanding the Sassenplaat nature reserve, replenishing the Hoogezandsche Gorzen mud flats and covering 590 ha of polluted bed. Van Oord was responsible for half of all the activities including dredging, coastal and shore protection and dry earth movement.

Our results
The Department of Public Works can now store polluted dredging spoil from the lower reaches of the rivers at the site. With a depth of about 45 m below seas level, the site can store approximately 10.2 million m³ of spoil, which will take 20 years. Once the site is full, it will be covered with clean soil and turned into a nature area.