This thesis explores the potential of a fixed artificial bypass system for a sustainable and eco-friendly approach to coastal management in IJmuiden. The presence of the IJmuiden Port disrupts the natural processes, causing significant morphological changes to the coastal area. Current management practices require frequent dredging and nourishment to mitigate the erosion of the downdrift coast and maintain the depth necessary for navigation in the channel and port. These activities result in significant emissions and adverse ecological impacts. Particularly affecting benthic life, organisms living in or on the seabed. Implementing a fixed artificial bypass system, already proven successful in similar projects globally, emerges as a potential solution to reduce dredging and nourishment activities. This system aims to restore the natural sediment transport by pumping sediment from the updrift to the downdrift side. In addition, its more continuous discharge of sediment is anticipated to be less disruptive for benthic life compared to traditional nourishment methods. The best-case scenario calculation performed in this thesis presents that an artificial bypass system at IJmuiden could potentially reduce dredging activity by 3.5% and nourishment activity by 37%. To assess whether these reductions can be achieved, this thesis introduces a newly developed framework for assessing the effectiveness of sediment bypass concepts based on four performance indicators: (1) Dredging Activity of Channel and Port, (2) Sediment Demand of Downdrift Coast, (3) Impact on Benthic Community and (4) Feasibility. This method includes simulating the response of the coastal system after implementing varying bypass concepts using a Delft3D model. The Delft3D model’s applicability and predictive skill are assessed via hydrodynamic and morphodynamic validation. Concluding that the model can reproduce the general trends but introduces numerical errors in the exact quantification of the morphological development. Despite this limitation, the output from these Delft3D simulations was used to evaluate the response of different artificial bypass concepts based on the four performance indicators. The first two indicators are based on the simulated sediment transport values and assessments of the development of the bed. The evaluation of the third indicator is based on a calculation performed using the developed benthic evaluation tool, named the 'Benthimeter'. This newly developed tool provides a method that intends to visualize and quantify the impact on the benthic community induced by nourishment activity. Although the Benthimeter requires further calibration and validation, it marks a good first step towards integrating ecology into coastal management. The results of this thesis demonstrate that the coastal system of IJmuiden allows for sediment withdrawal, where allready 10% of the required annual sediment trap was observed within one simulated month. Also northward sediment dispersal towards the downdrift coast was observed at simulations, indicating that such a system could reduce the sediment demand. These findings provide confidence that the principles of bypassing sediment around the port of IJmuiden hold. Consequently, it is anticipated that an artificial bypass system would, to some amount, reduce the need for dredging and nourishment activity. Also, the calculated impact on the benthic community confirms the hypothesis that a more continuous nourishment approach reduces the impact on the benthos. While the findings of this study provide an initial indication of the potential effectiveness of an artificial bypass system at IJmuiden, they do not provide long-term effect estimates. Further research is suggested to examine the primary drivers of dredging and nourishment activity, along with efforts to simulate the equilibrium state to evaluate the long-term effects. The most important contribution of this thesis is the introduction of innovative tools, guidelines, and effective methods. This framework can be used in future research to improve our knowledge of sustainability and ecology in coastal practices.

Irmão is a beach restaurant located in the region of Lisbon in Portugal and has been taken over by the new owners one year ago. Since the takeover, the owners of Irmão have been trying to work in a sustainable way, but there is always room for improvement. In addition, Irmão may have to move 100 metres inland due to a possible change in local regulations. Because of the uncertainty in the course of events, this report is written as guideline in order to make the current restaurant more sustainable and as a guideline during the design of the new beach restaurant, should the restaurant have to be relocated. The aim of the report is therefore to provide beach restaurant Irmão with a consult on how to establish and operate a more sustainable beach restaurant, in present or future times. The study, executed at Irmão, focused on three main themes; the water system, waste management and the energy system. The level of sustainability in these areas is quantified in three ways, namely: the use of resources such as fossil fuels and groundwater; the emission of greenhouse gases CO2, NOx and CH4; the pollution of the direct environment, for example waste that ends up in nature or polluted waste water that flows into the soil. The present and future times refer to the two different scenarios used to implement sustainable solutions. If the restaurant is allowed to stay at its current location, it is referred to as the Improved Irmão Scenario. If the location has to be changed, it is referred to as the Future Irmão Scenario. For the Improved Irmão Scenario, the boundaries and limits of the current restaurant are taken into account and the design is carried out within these limits. For the Future Irmão Scenario on the other hand, these limits are loosened and the design is carried out from scratch. To provide Irmão with a consult how to establish and operate a more sustainable beach restaurant, three steps were taken. First, the current situation of the three subjects is analysed to get a clear understanding of the current situation. This is done to have a baseline against which the final improvements can be compared. Secondly, different solutions to make Irmão more sustainable, within the three main topics, are compared using a multi¬criteria analysis to determine the most promising solutions. Thirdly, the final solutions are elaborated for the Improved Irmão Scenario and for the Future Irmão Scenario. Regarding the Water system, the analysis showed that the water consumed at Irmão partly originates from the water grid and partly from the borehole in the dunes. The water use is estimated to cause an emission of 182 kg CO2 annually, leaving little room for improvement in emission reduction as this is a relative low amount. However, the water system is currently not water-efficient because it does not contain any water circularity and the water system does not contain any water saving equipment. Improvements regarding water usage are therefore possible. Regarding waste management, the analysis showed that currently, only residual waste is not recycled. Therefore, the section on waste management focused on making residual waste more sustainable. Regarding the energy system of Irmão, it became clear from the analysis that Irmão currently consumes propane gas and electricity from the local electricity grid. Both the consumption of propane gas and electricity from the local grid contribute to an emission of 26.8 tonnes of CO2 annually. From all processes carried out during the operation of Irmão, only the consumption of propane gas leads to an emission of NOx, namely 382 kg NOx annually…