Community Water Watch: Measurements, Forecasts and Impacts

Dar es Salaam is subject to regular flooding, especially from the Msimbazi River, causing tens of deaths and over $100 million damages per year. Dar es Salaam is not an exceptional case, as many cities in the Global South face rapid urban expansion, which causes increased impermeable services, clogging of drains by sediment and solid waste, as well as encroachment of the floodplains. Although in the long term, structural measures are needed, much is to be gained short term by a flood early warning system that aims to increase situational awareness and optimise allocation of resources during and after floods. The Community Water Watch project, which contributes to the Tanzania Urban Resilience Program, addresses these aspects through a mixture of data streams.

In an online dashboard, these three data streams come together to create meaningful information. First, a dense network of TAHMO weather stations and two hydrological stations report in near-real time the atmospheric input and state of the system. Second, a hydraulic model uses this information to provide forecasts in terms of discharge, flood levels, and flood extents. Finally, social media platforms, such as Twitter, Telegram, WhatsApp, and JAMII Forums, are continuously searched for texts and photos concerning flooding to provide an overview of flood impacts and ways in which people are dealing with them. Tailor-made dashboards have been built to cater to different users such as the Tanzania Red Cross Society and the local transportation company DART. Due to the intense co-creation processes during the design of the system, these dashboards have already produced actionable information that has prevented damages and possibly has saved lives. The solution is very scalable to any city dealing with similar flood problems.