SUMMARY
This study deals with the cleaning of collectors and the management of floods in the city of Cotonou. The city has primary and secondary collectors to drain rainwater. These collectors have outlets for outlets, which are: the sea, the lagoon and Lake Nokoué.The natural, anthropogenic factors, the dysfunction of urban waste (liquid and solid) added to the rain risk related to the reflux of the receiving environment due to the rainfall plays an important role in the damages related to the mismanagement of the rainwater and consequently to the 'flood. The appearance of floods is not without repercussions on the socio-economic plan of the city. This justifies the validity of this work which focused on the management of floods in urban areas: the case of the Cotonou city in Benin. The results obtained show that the cleaning of the collectors comes to free the rainwater pipes of their waste and facilitate the drainage of the wastewater towards the lagoon bank. This in order to prevent the rainy season and to avoid possible cases of flooding.