The Port of Rotterdam is the dominant maritime gateway of the North Sea region and has repeatedly expanded seaward to accommodate increasing maritime, industrial, and logistical demand. Following large-scale developments such as Maasvlakte 2, the Port of Rotterdam is now assessing new spatial expansion options. One option is a direct seaward extension of Maasvlakte 2, referred to as a Seaward Port Expansion (SPE). Five design alternatives have been developed for this concept, denoted A1, A2, B1, B2, and C, representing progressively larger seaward extensions.

An important concern for the Port of Rotterdam is the potential effect that a future seaward expansion may have on fine sediment dynamics and, consequently, on maintenance dredging. The Port of Rotterdam depends on continuous dredging to maintain nautical depths in its access channels and port basins. After the construction of Maasvlakte 2, annual maintenance dredging volumes increased substantially in subsequent years. This raises the question of whether a future SPE could trigger an increase in siltation and dredging demand. The central hypothesis is that the modified coastal geometry may alter flow patterns, mobilise offshore fine sediment, increase fine sediment import through the Maasmond, and thereby increase sediment accumulation within the port.

This research addresses the following research question: How do alternative SPE designs affect maintenance dredging demand in the Port of Rotterdam through changes in hydrodynamics and fine sediment transport? To answer this question, a process-based framework is combined with numerical modelling using Delft3D-FLOW and DELWAQ. The framework tracks the response of fine sediment to the SPE designs from the offshore domain, through the Maasmond transect, and into the port basins.

The model results show that the SPE designs strengthen tidal flow contraction around the seaward expansion, increasing flow velocities and bed shear stresses near the curvature of the designs. Clay and fine silt remain largely in suspension offshore and show only limited sensitivity to these hydrodynamic changes. Coarse silt/micro floc responds more clearly, with reduced bed mass in the scour area and increased accumulation potential in adjacent low-energy zones.

At the Maasmond transect, the SPE designs do not increase fine sediment import into the port. Designs B2 and C reduce the net import of coarse silt/micro floc by 4% and 9%, respectively, mainly due to lower near-bed sediment availability caused by increased offshore retention. Consistent with this, the SPE designs do not lead to a systematic increase in fine sediment accumulation within the port. Within the applied model set-up, and excluding storm events, morphodynamic feedback, and construction-phase effects, the SPE designs are therefore not expected to increase maintenance dredging demand through changes in hydrodynamics and fine sediment transport alone. ... Read more

The erosion problem along Playá Union presents significant challenges for future port expansion at Puerto Rawson. This research seeks to address the question of how to achieve a sustainable and durable port expansion, while minimizing environmental impacts, particularly concerning sediment imbalance along the coastline? Using 30 years of wave data, both normal and extreme wave conditions are simulated with SWAN, a numerical based wave model. Conceptual port expansion designs are developed, resulting in a final design with an integrated fully dimensioned breakwater. Based on visual inspections, data, and research, a new cement mixture is proposed for the breakwater armour units. A Life Cycle Assessment evaluates the environmental impact, while the effect on alongshore sediment transport is assessed using the SWAN model outcomes and the CERC formula. Visual inspection of the current breakwaters lead to a 6.3% reduction in material use in the new breakwater through reuse of armour units. Furthermore, the proposed cement mixture integrates porphyry quarry waste as the coarse aggregate, a choice also supported by prior research in sustainability. With the new End-of-Life approaches added, the total shadow costs are reduced by 22%. The hydrodynamical analysis and model result in extreme wave heights up to 3.98 m at the toe of the breakwater. By applying a neural network and a k-means algorithm on the wave data, five regular wave conditions are run in the SWAN model. The alongshore sediment transport is impacted by new breakwater concepts. Relying solely on the breakwater layout to counteract erosion north of the port, however, does not prove to be a viable approach. Based on design criteria and aspirations, the final conceptual design proposes the removal of the existing southern breakwater, while retaining sufficient space for future port expansion. The breakwater, integrated in the final design, is dimensioned based on standard design principles. To conclude, the data and model provide valuable insights into the coastal dynamics around Puerto Rawson. The proposed concrete mixture, along with the End-of-Life solutions, minimize environmental impact and enhance durability of the armour units. The sustainable breakwater design, effectively integrated into Puerto Rawson, accommodates for future port expansions ... Read more