The Port of
Rotterdam Authority is currently examining whether it would be realistic to
expand its new dredging programme in Rotterdam with water injection dredging.
The current study fits within the Port Authority’s PRISMA research programme,
which looks into new dredging methods and how sediment reacts to these
techniques. The purpose of PRISMA is to improve the efficiency of dredging in
the port area and reduce the associated carbon emissions.
Every year, some 5 million cubic metres of dredged material are
removed from the port basins
The Port Authority
is responsible for keeping Rotterdam’s basins and waterways at the required
depths. Every year, some 5 million cubic metres of dredged material are removed
from the port basins – equivalent to around 500 football pitches covered with a
metre-thick layer of spoil.
Water injection dredging most promising to remove clean sediment along
berths and waterways
dredging is seen as the most promising means by which to remove clean sediment
along berths and waterways for maintenance purposes. The technique involves
injecting water into the soil of the project site. This creates a homogeneous
mixture of water and sediment, which then flows in a specific direction under
the influence of gravity and/or currents.
Over the past two
years, the Port Authority has conducted trials with water injection dredging in
Calandkanaal, having set up a sludge repository in the waterway for this
purpose. Injecting the sediment with water once every 6 to 8 weeks rather than
removing it with a trailing suction hopper dredger has cut dredging costs at
the site. In addition, water injection dredging is used at sites in the port
area that are difficult to access, as well as frequently occupied berths. As a
result, port users experience less hinder from shallow berths and dredging
operations that impede freight handling.
PRISMA, PRogramma Innovatie Sediment MAnagement
PRISMA is an
acronym for PRogramma Innovatie Sediment MAnagement. This programme was set up
by the Port of Rotterdam Authority to explore new innovation opportunities
within its dredging programme and increase insight into sediment’s specific
characteristics. The PRISMA studies are performed in partnership with various
research institutes, including Delft University of Technology, Deltares and