<p>In the past decades, cities in the Global South have witnessed rapid urbanisation coupled with population growth. This trend characterising the growth and expansion of cities has also yielded in unplanned urban sprawl. Against this backdrop, many of the cities in Africa and elsewhere have recorded the growth and expansion of human settlements at the city fringes and in peri-urban areas. Such settlement patterns often disregard sustainable human settlement planning due to the expanding grey environment (building of houses) in ‘protected’ wetland areas. Utilising qualitative research methodology and drawing from authors’ observations, data from grey material gleaned from residents’ associations and newspaper articles we examine how the expansion of the housing sector in wetland areas in Harare affects urban sustainability, city planning, human security and impacts on the realisation of interlocking sustainable development goals (SDGs) particularly Goal 11. This enduring trend attests to the unrelenting neglect of implementing human settlement policies and by-laws in accordance with proper urban and town planning to realise sustainable cities. Researching such a terrain aid a better understanding of the policy shortfalls in local governance, human settlement and spatial planning in African cities and how this affects the realisation of sustainable cities.</p>