Integrated water resource management in sub-catchment areas is imminent in Kenya since the review of Water Act in 2002. Subsequently, this research analyzed the water resources governance dynamics of Rwamuthambi sub-catchment and made key recommendations for sustainability. An exploratory descriptive design was adopted. Data was collected through 203 questionnaires, 15 key informant interviews, semi structured interviews and observations. Spearman’s rank correlation (R), Kendall’s coefficient of concordance (W), Likert scale and descriptive statistics were used to analyze the data. 32% of the local community respondents ranked public participation as most effective in wetland conservation while 33% indicated that the WRUAs improved wetland sustainability through civic education and sensitization. The results revealed that stakeholder sensitization on sub-catchment conservation was the least important while public participation (W= 0.1, p< 0.05) was the most important consideration. It also emerged that pre-WRUA enforcement strategies were effective. In addition, there was a strong negative correlation between poor enforcement of policies and poor institutional capacity (R (23) = -0.77, p= 0.03) in sub-catchment activities. Therefore, there is a need to promote land owners’ participation and technical and financial capacity building for WRUA committee members. The study recommends domestication of policies to address intrinsic sub-catchment matters and adoption of pre-WRUA era conservation strategies of enforcement as ways to promote sustainability through governance.