Pastoralist communities in Northern Kenya face increasing water security risks attributable to disruptions in their socio-ecological environments. Sedentarized pastoralists, women, and children are most vulnerable to spatial-temporal variations in water availability. This vulnerability is exacerbated by embedded power relations within existing socio-cultural and water governance systems. A preliminary study carried out in 2016 examined pastoralist women’s disempowerment in relation to the domestic water security constraints they face. The research found anecdotal evidence that women with diversified livelihoods and social capital are more resilient to water stress. The follow-on study was carried out in 2018 and aimed to provide empirical evidence on factors behind water security and to identify factors that enhance resilience for vulnerable pastoralist communities. The study covered both urban and rural communities in Samburu County and applied a mixed-methods research methodology incorporating quantitative and qualitative research approaches. The study was also used to test a scale for measuring household water insecurity which could potentially improve the methodology for assessing shock-related stress in these high-risk communities. Results show extreme levels of water insecurity, especially in rural areas, and indicate a close relationship between water security and social capital as indicated in the earlier study. Livelihood diversity does not appear to influence water security but households with higher numbers of livestock tend to be more water insecure than households with smaller herds. This is supported by reports from women that the additional burden of watering homestead-based livestock makes them more vulnerable.