Blocked Drains and Rising Waters: Solid Waste Mismanagement as a Driver of Urban Flood Risk in Nigeria

Abstract Urban flooding is a recurrent natural disaster in Nigeria, displacing millions of people and causing major economic losses. This scoping review examines solid waste mismanagement as a driver of urban flood risk in Nigerian cities. The review followed the Arksey and O’Malley framework and was reported using the PRISMA-ScR checklist. A total of 100 studies were synthesised narratively, guided by the Pressure and Release (PAR) model. Findings show that only 20 to 30% of municipal solid waste is collected nationally. Uncollected waste, especially plastics and sachet water bags, blocks drainages at surfaces, inlets and channels. This reduces hydraulic capacity and amplifies flooding across Nigerian cities. Weak enforcement, fragmented governance and poor funding aggravates this problem. Consequences include property loss, livelihood disruption and outbreaks of cholera and typhoid. However, none of the reviewed study isolated waste as a measured hydraulic variable in flood models. The review concludes that drainage investment alone cannot reduce flood risk without waste governance reform. Hence, extended producer responsibility, wider collection coverage, routine desilting and coupled waste-hydraulic modelling are recommended. Without implementing all of these, Nigeria as a country will not be able to achieve SDGs 6, 11 and 13.