SUMMARY
Like most countries in sub-Saharan Africa, Benin’s economy is based on the primary sector, including agriculture, livestock and fishing. Agriculture alone employs three-quarters of the workforce and contributes 44% to the Gross National Product (GNP) according to the World Bank (2015). However, the production of food crops does not manage to cover the food needs of the populations every year. The permanent concern of the population is to have enough water to allow them to practice on the one hand the off-season crops (market gardening) and on the other hand to secure the water supply for the population and for livestock. These recorded difficulties justify the merits of this study, which proposes to approach the technical study of the construction of the Worogui Adja dam in the commune of Tchaourou in Benin.