FELIX KAIZA/World Bank Group/Agencies
Factors contributing to the devastating impact of perennial annual flooding in the Dar es Salaam City’s Msimbazi River basin have been identified.
Making a follow-up on a recommendation by Iftar diners hosted by the Kilimanjaro Dialogue Institute (KDI) calling for a delivering solution to disastrous effects on informal and low-income settlements along the river banks, Azaniapost landed on a DfID-funded flood modeling initiative jointly implemented by the World Bank and the Government of Tanzania.
Tagged Tanzania Urban Resilience Programme, the initiative aims at analyzing the extent of erosion along the river and better visualizing the impact of potential interventions.
World Bank Group reports observe that historically under-addressed soil erosion plays a major plaguing role of the Mzimbazi River basin leading to untold toll of floods related losses of assets, critical infrastructure, and life.
They say soil erosion enables water to escape the confines of the river’s natural borders and produces sedimentation, which obstructs river flow and increases flooding.
They also point out that community-led efforts to reinforce the collapsing riverbanks have involved the intentional dumping of solid waste, a makeshift solution that has further exacerbated the issue.
The reports trace policy makers’ failure to design accurate sustainable flood solutions for the basin to an outdated soil map which does not reflect the impact of urbanization and thus ending up with not showing the whole story for Dar es Salaam.
They quote one expert as saying “only one general soil type has been considered by decision makers in the past, severely limiting accuracy of analysis as it doesn’t account for how soil in different areas reacts differently to water.”
To fill this data gap without having to resort to traditional costly international expertise programs, World Bank’s Urban Resilience programme advocates for the adoption of affordable and local solutions to flooding in Dar es Salaam.
Adopting open web applications and simple measurement tools, 16 young Tanzanian professionals and students have collected soil samples from 643 strategic points across the city, covering an area of over 2,752km².
These profiles identify which areas are most susceptible to erosion, which are experiencing the most erosion, and how this influences flooding and river dynamics. The resulting soil map will inform a comprehensive sedimentation study of Dar es Salaam, and the actions that need to be taken regarding urban development around the Msimbazi River.
Besides helping leaders make informed decisions, the project proves that critical disaster risk data collection does not have to be outsourced—that local knowledge and tools can support successful and sustainable solutions, and the capacities of young, aspiring practitioners can be nurtured in the process.
Dar es Salaam, which is East Africa’s biggest city, is projected to become the third urban setting on the continent in terms of population after Lagos of Nigeria and Zaire’s Kinshasa.