This report investigated the interplay between water quality, sanitation, hygiene and gender by examining distinct variables of water quality and their varying impacts on gender like reported water-related illnesses of males and females, and the consequences of water quality, sanitation, and hygiene on menstrual hygiene practices, particularly focusing on a low- and middle-income country- LMICs. This report presents the key findings, outlining a framework and guidance for examining gender-specific impacts stemming from poor water quality and WASH practices through a piloted case study in Abeokuta City, Nigeria, to serve as a preliminary guide for conducting comprehensive, site-specific assessments. The piloted Differential Impacts Assessment, DIA framework is a 5-step approach, guiding the evaluation of gendered impacts from method design to the field activities, which include water sampling and laboratory analysis, public survey, and health data collection, to the data and gender analysis. The focus on low- and middle-income countries underscores the importance of DIA in such regions for better health and socioeconomic outcomes, promoting inclusive development. The study results reveal unsettling, largely unseen gender disparities in exposure to health-related risks associated with non-utility water sources and highlight pronounced differences in water source preferences and utilization, the burden of water sourcing and collection, and health- and hygiene-related practices. Specifically, this preliminary assessment indicates an alarming inadequacy in accessing WASH services within the pilot study area, raising considerable doubts about achieving SDG 6 by 2030. While this finding is worrying, this report also discusses the lack of a standardized protocol for monitoring water-related impacts utilizing sex-disaggregated data, shedding light on the unseen global-scale gendered impacts. The report warns about the water safety of non-utility water sources. Without point-of-use treatment and water safety protocols, the water sources are unsuitable for potable uses, potentially posing compounded health risks associated with microbial contaminations and high calcium content, particularly affecting boys. Girls are likely the most affected by the repercussions of water collection, including time constraints, health implications, and safety concerns. Men and boys face a higher risk related to poor hygiene, while women may be more susceptible to health effects stemming from toilet cleaning responsibilities and shared sanitation facilities. Despite the preference for disposable sanitary pads among most women and girls, women maintain better menstrual hygiene practices than girls. This age-specific disparity highlights potential substantial health risks for girls in the near and distant future. Enhancing women's economic status could improve access to superior healthcare services and significantly elevate household well-being. The report calls for targeted actions, including urgent planning and implementation of robust water safety protocols for non-utility self-supply systems and mainstreaming gender concerns and needs as the “6th” accelerator for SDG 6. The piloted methodology is scalable and serves as an introductory guide that can be further refined to explore and track site-specific differential health and socioeconomic effects of inadequate water quality, especially in locales similar to the study area. The report targets policymakers and donor organizations advocating for sustainable water resource development, public health, human rights, and those promoting gender equality globally