Samenvatting

This research is conducted as a bachelor thesis of the programme Delta Management at the HZ University of Applied Sciences, Vlissingen and in cooperation with the Living Lab Water Indonesia by nuffic neso and Institut Teknologi Sepuluh Nopember, Surabaya. Plastic debris hindering recovery
and reforestation efforts of mangrove forests in Surabaya, Indonesia and the severe impacts of marine debris on marine biota serve as a problem statement and an objective to find a simple, cheap and sustainable solution to floating trash in Surabaya’s urban rivers, which empowers and benefits local poor communities has been formulated. Since 80% of marine debris are derived from terrestrial sources, the area of intervention chosen in this research are urban river stretches just before entering the marine environment. In order to find a suitable solution according to the above-mentioned criteria, an area analysis with the purpose to find an appropriate location for a pilot project and to base the research on, has been carried out. The chosen site in Sidotopo, North Surabaya has been researched by ways of interviews with local officials, local inhabitants, waste scavengers as well as managers of waste banks so as to explore levels of awareness and willingness to cooperate, the availability and composition of floating trash and available materials as constructional input for a potential solution by means of a floating trash barrier. The collected data has been analyzed in the form of multi-criteria analyses with the aim of identifying the most appropriate and suitable materials to be used. Several designs for a floating trash barrier in various circumstances have been assembled, while incorporating trash removal mechanisms, and an inclusion of the retrieved trash into existing and new locally specific waste management principles and processes.
Additionally, a financial analysis has been conducted, considering tangible costs and revenues, as well as social and ecological benefits. The levels of willingness of cooperation and awareness have been found sufficient for the selected pilot site, while the most suitable materials for construction of a barrier have been identified as plastic bottles as floatables, plastic rope derived from extracted plastic bottles from the river as cohesion and connection material and bamboo as anchoring materials. The designs produced provide a low-tech, simple and cheap solution to extract trash materials from the river, while outlining how to process the retrieved trash efficiently, whilst creating financial benefits from the sales of valuable materials to waste banks. The proposed solution furthermore provides social and local empowerment, reduction of pathogens and heavy metals in addition to a possible reduction of eutrophication and the provision of habitat and nursery for herbivorous fish species by incorporating concepts of floating islands into the designs. Lastly, the concept outlines have been evaluated to be successful on a larger scope and in differing areas by means of implementation plans.