This study explored the influence of leadership styles on decision-making in water conservation initiatives in Kenya, focusing on the Nairobi City Water and Sewerage Company (NCWSC). The main objective was to assess how transformational, situational, servant, and charismatic leadership styles affect decision-making effectiveness in water resource management, infrastructure development, and service delivery. Despite NCWSC’s critical role in sustainable water conservation, persistent challenges in strategic planning, policy implementation, and stakeholder engagement are often linked to leadership inefficiencies. Guided by Charismatic Leadership Theory, Situational Leadership Theory, and the Rational Decision-Making Model, the study targeted NCWSC executives, department heads, managers, and technical officers. A stratified random sample of 360 respondents was selected, and data were collected using semistructured interviews and questionnaires. Mixed methods were employed: thematic analysis for qualitative data and SPSS (version 29) for quantitative analysis. The findings revealed that situational leadership had the greatest influence on effective decisionmaking, followed by transformational, charismatic, and servant leadership. Weaknesses identified included limited innovation, inadequate staff empowerment, and lack of flexibility. The study recommends fostering innovation through regular brainstorming workshops, enhancing employee participation through feedback mechanisms, and integrating charismatic motivation with structured governance for long-term conservation success. Strengthening leadership adaptability and inclusivity is crucial for improving water conservation outcomes and achieving sustainable water governance at NCWSC.