Water demand and supply in Dar es Salaam : A WEAP-model to estimate future scenarios

Abstract: The water and sewage company in Dar es Salaam, Tanzania has expressed a lack of integrated development plan for their service area. The current planning does not combine the social, economic and environmental stakeholders. This project investigated how rapid urbanisation and Tanzania’s vision of going from a low to middle-income country before 2025 will affect the water demand together with an investigation of the sustainability of the water supply in the city, Dar es Salaam. Furthermore, the study also investigated the collected historical data from the city’s biggest water supplier, Ruvu river, to examine if there are any changes in waterflow. The study used previous research, collaboration with students and interviews with the stakeholder and experts to collect information and estimate historical patterns. With the software, Water And Evaluation Planning (WEAP), the study processed the historical data to simulate future scenarios with aim on sustainability and development mentioned above. The study shows an increased demand in the future as a result of both urbanisation and economic growth and unmet demand in all scenarios. From the historical data the study shows a small decrease in total quantity and an upgoing trend of the peaks that occur during the biggest annual rainy season. Lastly, the study finds a need of looking at the current sources of supply to achieve sustainable utilization of the resource.