Integration of social and cultural dimensions in the assessment of environmental flows: case of the Ouémé delta in West Africa

The use of environmental flows as a technique for the diagnosis and sustainable management of aquatic ecosystems in West Africa is relatively new and cautious, despite being broadly implemented for many years in Western countries and Southern Africa. The present study, the first to evaluate the environmental flows in Benin, concentrates on the deltaic region of the Ouémé River. The assessment utilises the Building Block Methodology approach, and incorporates ecological, socio-cultural, and religious dimensions. The assessment focuses on the alterations in river flows and the impact on local communities’ livelihoods, beliefs, and cultural and religious practices. The results indicate that the population of the Ouémé Delta are significantly impacted by changes in the river’s flow. Indeed, floods play a crucial role in people’s daily routines and livelihoods, while a significant decrease in river flow results in economic instability. Moreover, there is a strong link between specific religious customs in the area and the river’s flow. To maintain the current provisioning, regulating, and cultural ecosystem services in the Ouémé delta, The study recommended to allocate 100% of the River Ouémé’s natural flow during low-water periods (December to May) and 50% of the natural flow during high-water periods (June to November). This allocation ensures that the environment’s water needs are met and will contribute to preserve the Ouémé delta’s ecosystem, ensuring the sustainability of its ecological habitats and biodiversity. However, the implementation of these recommendations would require more debate and a real consensus on the priority between development and environment.