Growing urbanization in sub-Saharan Africa, with its attendant degradation of natural vegetation, is a real scourge. It takes the form of urban sprawl, with its corollary of native vegetation degradation. The aim of this study is to assess the impact of urban sprawl in Brazzaville and the related degradation of the vegetation covering on the urban site. The methodological approach was based on the collection of documentary and field data, as well as the analysis of Landsat satellite images from 2002, 2012 and 2022. The results show a regressive evolution of natural plant formations in favor of urbanization. The area of vegetation cover fell from 17,523 ha in 2002 to 8355.5 ha in 2022, representing a regression rate of 52.32% in 20 years. At the same time, the urban area has grown from 12,164 ha in 2002 to 29,892 ha in 2022, an increase of 145.74%. This deterioration in vegetation cover is reflected in water erosion, resulting in silting-up and flooding of homes and sanitation facilities.