Potential Nature-Based Solutions for Wastewater Treatment in Mozambique’s Coastal Areas

Overview & Synopsis

Mozambique’s coastline is one of Africa’s most ecologically rich - and most vulnerable. Home to thriving mangroves, diverse marine life, and millions of people, these coastal areas are under mounting pressure from rapid urban growth, inadequate sanitation, and intensifying climate hazards. Today, land-based pollution, overwhelmingly from untreated wastewater, accounts for 80% of the contamination reaching these coastal waters. Further, the combined pressures of rapid urbanization, flooding, high groundwater level, and saltwater intrusion make this area one of the most complex sanitation challenges on the continent. This first in a series of reports, funded by PROBLUE and developed in collaboration with the Government of Mozambique, explores whether nature itself can be part of the answer. Drawing upon the case studies in the two coastal cities, Maputo and Quelimane, the study identifies potential Nature-based Solutions (NbS) for wastewater treatment suited to tropical coastal settings - from constructed wetlands and aerated ponds to EcoSan toilets, hydroponics, sludge treatment wetlands, and mangrove restoration. Solutions are evaluated through spatial analysis, stakeholder engagement, multi-criteria assessment, and cost-benefit analysis, with climate resilience - flood protection, salt tolerance, and drought adaptation - built into every recommendation. The study shows that NbS can deliver reliable, affordable, and ecologically restorative wastewater treatment across both urban and rural contexts, while generating co-benefits for biodiversity, livelihoods, and community well-being. The report offers a practical roadmap for embedding these solutions into Mozambique's national sanitation agenda and Blue Economy strategy - making the case that healthier communities and healthier coasts are goals best pursued together.