the treatment and conditioning of the city’s western slopes are at the heart of the management of the natural risk in Quito. The deconstruction of this policy reveals both a representation of development challenges and a logic of controlling urban margins. Indeed, the development of the slopes has led to the fight against threats that jeopardise the functioning of the sanitation network and urban mobility. From the outset, this has been part of a logic of controlling urban sprawl and territorial marginalisation, as the authorities wish to integrate them into municipal planning. The evolution of the work also shows that combating the ‘natural’ risk serves the policy of improving the living environment.