Nature-Based Solutions for Wastewater Treatment in the Hilly Areas of Mwanza City, Tanzania

Sustainable wastewater management is a critical challenge for urban and rural areas worldwide. This challenge is particularly pronounced in hilly regions, where topographical constraints, limited accessibility, and resource scarcity often hinder the implementation of conventional wastewater treatment systems. Nature-based solutions (NBS) emerge as a sustainable and cost-effective approach in such contexts. These solutions leverage natural processes and ecosystems to treat and manage wastewater, ensuring environmental sustainability and public health protection. Sustainable Development Goal (SDG) 6 underscores the need for equitable sanitation, improved water quality, safety, and restoration of water-related ecosystems. Globally, over 80% of wastewater is released untreated, posing significant public health and environmental risks. Approximately 2.4 billion people need improved sanitation, and 3.6 billion, half of the world’s population, use sanitation services that leave human waste inadequately treated, causing 1.4 million preventable deaths annually. In Tanzania, achieving SDG 6’s sanitation target by 2030 requires sustainable wastewater treatment solutions to preserve ecosystems. In Mwanza City, only a tiny fraction of households are connected to centralized sewer systems, with 90% relying on on-site sanitation like pit latrines and septic tanks. Poor sludge management contributes to water-borne diseases, and the city’s hilly terrain complicates sanitation, leading to sewage overflows that contaminate Lake Victoria. This study aims to design nature-based solutions (NBS) for wastewater treatment in Mwanza’s hilly areas, including Butimba, Igogo, Isamilo, Mkuyuni, Mkolani, Kirumba, Kitangiri, Nyakato, Nyamanoro, and Pasiansi. The research explores NBS technologies, such as waste stabilization ponds, constructed wetlands, and decentralized systems, to reduce pollution and protect Lake Victoria.