Abstract
Despite significant investments in rural water infrastructure, many systems in semi-arid areas such as Chemba District continue to experience declining service levels, frequent breakdowns, and premature failure, raising critical concerns about the long-term sustainability of water service delivery. This study examined rural water service sustainability variation in semi-arid Tanzania using cross-sectional household survey data from This study examined rural water service sustainability variation in semi-arid Tanzania using cross-sectional household survey data from 384 respondents in Chemba District. Sustainability was assessed using a composite index of perceived service levels, namely water quality, quantity adequacy, reliability, accessibility, and affordability as proxies for the continued functioning of rural water services. Explanatory conditions were captured as composite indices representing financial conditions, institutional arrangements, technical performance, social organisation, and environmental stressors. Hierarchical multiple regression was used to estimate the incremental contribution of each domain to observed sustainability variation. Sustainability outcomes varied widely (mean 3.02; SD 0.95; range 1.00 to 5.00). The baseline model with socio-demographic controls explained a small and statistically insignificant share of variation (R² 0.095; p 0.227). Adding financial conditions produced the largest improvement in explanatory power (ΔR² 0.223; p 0.001). Institutional arrangements added a modest contribution (ΔR² 0.060; p 0.053). Technical performance did not improve model fit once finance and institutions were included (ΔR² 0.000; p 0.907), while social organisation and environmental stressors added small, statistically insignificant increments (ΔR² 0.017; p 0.306; and ΔR² 0.024; p 0.219). The final model was statistically significant and explained 41.9 percent of the variation in sustainability outcomes (R² 0.419; adjusted R² 0.297; p 0.005), with low multicollinearity. These results indicate that financial and institutional factors significantly explain variations in sustainability, reflecting the central role of effective management, timely availability of funds, and accountability mechanisms in maintaining service delivery. In contrast, technical performance did not significantly improve the model, suggesting that the mere presence of infrastructure is insufficient to ensure sustainable services in the absence of strong financial and institutional support. The study highlights the importance of strengthening governance and financing systems to improve rural water service sustainability in resource-constrained settings like Chemba.