Introduction
In Mocuba, Angoche, Alto Molocue and Namialo, 62–81% of households rely on individual latrines, and open defecation persists in vulnerable pockets. Flooding, waterlogging and proximity to rivers or wetlands put 9–12% of buildings in high-risk zones, where pits regularly fail and contaminate the environment. Economically vulnerable settlements, home to 70–87% of the population, are concentrated in these same high-risk clusters. Together the four towns, across Zambezia and Nampula provinces, have more than 300,000 residents.
Project info
- Client: SNV Netherlands Development Organisation
- Funder / programme: USAID, Small Town Sanitation Project
- Period: May 2024 – Sep 2024
- Location: Mocuba and Alto Molocue (Zambezia Province), Angoche and Namialo (Nampula Province), Mozambique
Scope
The project developed a citywide inclusive sanitation (CWIS) plan for each of the four towns. The team assessed existing sanitation conditions, identified risk-prone settlements and proposed safe, climate-resilient containment solutions. The work covered desludging access, conveyance infrastructure, the evaluation and upgrading of faecal sludge treatment plants (FSTPs), and greywater management.
Spatial analysis, risk modelling and water-sensitive approaches were combined to guide regulatory improvements, service delivery arrangements and financial planning, so that the plans address environmental vulnerability while remaining feasible for municipalities to implement.
Did You Know?
- Cyclone Freddy (2023) disrupted sanitation services across the region, damaging water points and heightening cholera risks.
- Angoche and Mocuba have the highest percentage of buildings in flood or waterlogging zones, increasing containment failures.
- Alto Molocue records up to 16% open defecation, one of the highest levels among the studied towns.
Services Delivered
GIS-Based Sanitation Assessment
A GIS-based assessment was carried out across all four towns, combining building footprints, risk layers, drainage networks and economic vulnerability mapping to produce a sanitation profile for each settlement.
Flood Modelling and Risk Mitigation
Risk modelling used elevation, slope, precipitation, waterbody proximity and drainage density to identify areas vulnerable to flooding and waterlogging. The results informed safe containment recommendations and the siting of resilient infrastructure.
Wastewater Management
Town-wide wastewater assessments guided improvements to existing containment, desludging systems and FSTP operations. The recommendations set out safe treatment pathways and stronger conveyance chains to reduce environmental contamination.
Greywater Management as Pilot Solutions
Greywater catchments were delineated using watershed and density patterns. Pilot Dry Weather Flow Interceptor (DWFI) systems were proposed in high-density neighbourhoods to intercept and treat polluted greywater before discharge.
Cost Estimates and Phased Plans
Phased investment plans were prepared, from containment upgrades to desludging improvements and treatment expansion, to keep implementation financially feasible and operationally ready.
Regulatory Reform Recommendations
Reforms were recommended for municipal by-laws, desludging service rules, tariff structures and monitoring systems to strengthen long-term sanitation governance.
Results
- CWIS plans delivered for four towns: Mocuba, Angoche, Alto Molocue and Namialo.
- Every settlement classified as suitable for networked or non-networked sanitation, with low-cost simplified sewer options explored.
- 9–12% of buildings identified in high-risk flood or waterlogging zones, with economically vulnerable clusters prioritised for immediate containment upgrades.
- Desludging access mapped for all settlements, with fleet sizing and desludging schemes designed for universal safe collection.
- Pan-city greywater plan, phased cost estimates and regulatory reform recommendations handed over to the municipalities.
Work Illustration
A multi-parameter vulnerability assessment, evaluating elevation, drainage density, flood exposure, waterbody proximity and settlement accessibility, showed that 9–12% of buildings across the towns fall within high-risk flooding or waterlogging zones. These areas frequently experience toilet backflow, collapsed pits and greywater stagnation.
The geospatial analysis also showed a strong overlap between risk and economically vulnerable settlements, where containment failures and desludging limitations compound public health risks. These findings were used to prioritise settlement clusters for immediate interventions and became a core part of the four-town CWIS planning framework.
