The effects of water management and climate change on catchment scale: The case of Salinja di Vlijt catchment on Bonaire

Master Thesis Water Systems and Global Change Group in partial fulfilment of the degree of Master of Science in 2023 master program Climate Studies at Wageningen University, the Netherlands. This master thesis is a contribution in the context of the BO project: Duurzaam regenwaterbeheer BES-eilanden.

Abstract This study examines the impact of climate change and water management choices on infiltration and runoff in the case of the Salinja di Vlijt catchment on Bonaire. Climate change will affect precipitation, temperature will increase, sea level will rise (at least 0.2 meters), and tropical storms will be more intense. This will influence the catchments hydrology – runoff will decrease in base flow and increase in peak flow. The current water management measures – drain pipes, channels, reservoirs, and dams – lead to nuisance flooding and partly are in need of maintenance. Evaluating different water management scenarios, rain barrels and rooftop disconnection systems with water storage can reduce runoff and improve infiltration, while additional infiltration trenches decrease catchment discharge and increase infiltration in specific sub-catchments. Extra reservoirs have limited impact on overall runoff and infiltration. Implementing selected measures can help mitigate the effects of changing urbanization and climate change in the catchment. Further research is required to explore the combined effects of measures and assess spatial feasibility. This study contributes valuable insights for effective water management strategies in the Salinja di Vlijt catchment, and the approach presented can be applied to other catchments.