Msimbazi Wetland Park : restoration of an urban flood plain in Dar es Salaam, Tanzania

Sammanfattning: Degradation of urban river systems is a global problem that poses challenges in Tanzania and other low-income countries, as well as in the rest of the world. To a large extent this is a result of fast urbanization, pollution and floods, that changes and deteriorate natural riverine systems and their ecosystems. Over the past ten years a rapid urbanization and population growth has occurred in Tanzania, particularly in Dar es Salaam. This has increased the demand of basic urban services, infrastructure, housing, and water. In the meantime, the city planning in Dar es Salaam has lacked to follow set plans, regulations and to update the plans. As a result of this, the city is now struggling with spatial disorder, poor infrastructure fast expanding informal settlements and inadequate city planning. One site seriously affected by all these problems is the Msimbazi River flood plain, situated in central Dar es Salaam. Pollution levels in the water and soil have reached very high percentages and due to the recent urbanization and lack of planning, the flood plain can no longer maintain and control the flood water in a sustainable way. This is also due to heavy seasonal rains, lack of infrastructure and clogging of drainage channels. Large parts of the flood plain have also been built upon with mainly many informal settlement which gets flooded every year. The thesis focuses on managing flood water, decreasing pollution levels in the water and soil, and restoring the riverine ecosystem. Four main research themes; restoration of urban river systems, flood water management, pollution reduction in urban watercourses and turning flood plains into multiple-use spaces, leads to specific design strategies that are presented to be applied on this specific site in Dar es Salaam and also on similar sites around the world. The project combines theoretical and practical knowledge in order to obtain a design proposal which considers strengths and weaknesses on site, restore the urban wetland and is also realistic to implement. The developed design proposal for the Msimbazi river and flood plain, Msimbazi Wetland Park, creates a multi-use green space which combines all of these strategies as well as important social and recreational functions. With this transformation and restoration, Msimbazi flood plain can restore its function as a retention area for floods as well as become a sustainable public green space for the citizens of Dar es Salaam.