Project ‘Flood Risk Accra’

By Lexy Ratering


A Project Team ‘Flood Risk Accra’ consisting of TU Delft and KNUST students (Kwame Nkrumah University of Science & Technology in Ghana), supervised by experts from HKV Lijn in Water and Witteveen+Bos were challenged to develop a methodology for urban flood risk assessment. They used the city of Accra as a case study. They are a very good example of how the use of social media can mobilize a lot of people and ask them to actively participate. Lexy Ratering, one of the participating students, shares the experiences of the team:

Floods are a serious problem in the city of Accra, Ghana. Every year heavy rainfall causes flooding in large portions of the city, business districts as well as poor neighborhoods. The damage is often extensive: disrupted traffic, lost property and even casualties.

Why is Accra not able to drain the rainwater properly? Project ‘Flood Risk Accra’ looks into the causes of the flooding and uses the city as a case study to develop a methodology on urban flood risk assessment. Urban floods are a problem in more African cities with a similar pattern of development: quickly rising populations, inadequate drainage infrastructure, institutional lack of coordination and poor solid waste management services. Climate variability and increasingly intense rainfall makes such cities into a ticking time-bomb. Action is required!

What could be done to help? The Project Team tested several tools and activities to gather information about the drainage system, given field data are scarce in the typical context of a developing city. Using smartphones, they collected technical data about the drainage system, such as dimensions, materials, state of the drainage network, flood level marks and waste accumulation. Using social surveys, the team interviewed inhabitants about their flood experiences and household waste management.

In addition to developing social surveys, the team spent effort on raising awareness about the effects of proper waste disposal on floods risk and tried to engage partners, stakeholders and inhabitants in the project. They used the internet and social media channels: a website, Facebook and Twitter, on which they posted updates to reach people actively and handed out flyers and business cards to draw attention to the platforms. People recognized them because they walked around with their measurement tools in the neighbourhoods and wore bright blue project T-shirts during their fieldwork.  One day they joined a garbage removal mission, organized by the City Council. Watching their project team clean the drains in front of their houses and shops made people think. “Why should Obroni’s (another word for foreigners) come in and clean our waste?

They also conducted an experiment to find out if they could collect valuable information on the drainage system via social media since most Ghanaians own a smartphone. Through ISocial TV, a Ghanaian TV programme, they launched the ‘social media experiment’. They recorded a video to call on citizens to upload their “#gutterselfie” through WhatsApp, including a geo-location. The objective is to analyze the pictures on dimensions used to map out the drainage system in space. They already received a lot of response: The video already has over 14,500 views and more than 480 people shared it. 153 people sent them a WhatsApp message. Although not all information is relevant (they receive blessings and comments and selfies without gutters), the experiment teaches valuable lessons and seems to be a promising tool for crowd-sourced flood risk mapping.  

Watch the video the Project Team has made to ask people to make 'Gutterselfies' here: