Built-in Flood Risk: the Intertwinement of Flood Risk and Unregulated Urban Expansion in African Cities

Abstract

Urban flood risk is significantly shaped by ground conditions and the built environment, which are constantly modified and transformed by human actions. This paper examines the intertwinement of flood risk and unregulated urban expansion processes in three selected sites in Accra’s expanding periphery. All three sites have been included in Accra’s urban extent since the 1990s, but differ with regard to the timing of development and socio-economic characteristics of residents. The research illuminates how flood risk is produced and “built-in” to the urban fabric through widespread practices associated with unregulated urban expansion processes, especially the persistent encroachment on water retention areas, wetlands and riparian zones and the highly fragmented provision of transport infrastructure in emerging residential areas in the periphery. Such harmful development practices are neither confined to homebuilders from poorer segments of the urban population nor spatially concentrated in low-income areas. The research highlights how the actions and inactions of a wide range of social groups and actors engaged in urban land administration and development contribute to flood risk in various ways, making flooding an increasingly alarming issue of citywide concern. Different stakeholders highlight fragmented urban governance as an underlying root cause for the obstruction of sustainable land and water management. Overall, the study calls for a more robust recognition of spatial planning and transport infrastructure provision in flood risk mitigation and highlights the urgent need for planning and governance practices that challenge the existing fragmentation of urban governance systems.

Flood risk reduction and resilient city growth in sub-Saharan Africa: searching for coherence in Accra's urban planning

“…There is a growing concern among scholars, including Amoako and Inkoom (2018), Alvarez and Cardenas (2019), Andreasen et al (2023), andWatson (2021), about the need for policymakers to address the complex issue of landownership to create more just, compassionate, and environmentally-friendly cities. Brazil has taken bold steps to address this issue by implementing new legal criteria that prioritize the social value of property over private rights.…”

“…Mainstreaming disaster risk reduction in spatial planning for urban resilience In today's world, as cities expand to accommodate the growing urban population, there is a need for numerous large-scale citybuilding projects. Experts such as Amoako and Inkoom (2018), Andreasen et al (2023), andWatson (2021), as well as global development organizations such as UNISDR (2015) and Kim (2019), emphasize the significance of understanding the art of city-building. The United Nations Sustainable Development Goals (UN-SDGs) adopted in 2015 brought about a renewed focus on urban planning.…”

How Does Flooding Influence Intra-Urban Mobility? The Case of Accra

“…Recent research indicates that the increasingly common flooding episodes within the city of Accra are a consequence of multiple factors, including unplanned development caused by ineffective land ownership and administration regulations. The largely unplanned expansion and densification of the city have led to a significant increase in the extension of impervious surfaces, leading to greater surface runoff during rainfall [10][11][12][13]. The higher vulnerability to flooding is, to some extent, associated with informal urbanization, poverty, and marginalization, which have led many people to settle in flood-prone areas [13,14].…”

“…The largely unplanned expansion and densification of the city have led to a significant increase in the extension of impervious surfaces, leading to greater surface runoff during rainfall [10][11][12][13]. The higher vulnerability to flooding is, to some extent, associated with informal urbanization, poverty, and marginalization, which have led many people to settle in flood-prone areas [13,14]. There is a process towards the filling up of vacant open spaces and many new buildings are constructed very near waterways or directly encroaching on riverbeds, resulting in narrowed flood plains.…”

“…This development exacerbates both the extent of, and exposure to, flooding in urban areas [11,12,15]. Additionally, inadequate drainage systems and garbage disposal practices further contribute to increased levels of flooding [11,13].…”