Water and energy are essential resources for human livelihoods and institutional functionality. In Mbeere South Sub-County, rising demand and unreliable supply threaten the sustainability of secondary schools. This study examines the factors influencing water and energy source choices in these institutions, guided by Resource Dependence Theory. A descriptive survey design was employed, targeting all 33 secondary school principals and two education officers. Data were collected using validated questionnaires and observation checklists, with a reliability coefficient of 0.82. Analysis using SPSS (v21) revealed a significant association (Fisher’s exact test, p = 0.003) between resource choices and influencing factors such as cost, technical feasibility, location, and policy incentives. The study recommends prioritizing reliability and cost-effectiveness in infrastructure investments and promoting awareness on sustainable practices. Findings contribute to policy formulation and resource planning in semi-arid educational environments.