This paper examines the contemporary intersection of global water scarcity—characterized as "Global Water Bankruptcy"—and the escalating climate emergency. As anthropogenic warming exceeds $1.1^\circ\text{C}$, the systemic disruption of the hydrological cycle has rendered traditional legal stationarity obsolete and pushed freshwater systems beyond planetary boundaries. Through a critical analysis of international instruments, including the 1997 UN Watercourses Convention and the 2004 Berlin Rules, this study evaluates the evolving tension between "Equitable and Reasonable Utilization" and the "No Significant Harm" rule in an era of decreasing supply. The research utilizes the 2025 Indus Waters Treaty abeyance crisis and the Grand Ethiopian Renaissance Dam (GERD) dispute to illustrate the fragility of transboundary agreements under hydro-climatic stress and shifting hydro-hegemony. Furthermore, it analyzes the landmark 2025 Advisory Opinions from the Inter-American Court of Human Rights and the International Court of Justice, which elevated environmental protection to jus cogens status and affirmed the existential legal duties of states to mitigate climate harm. Finally, the paper addresses the "legal void" surrounding climate-induced migration and the disproportionate impacts of water insecurity on women and girls, ultimately advocating for a transition toward adaptive, rights-based Integrated Water Resources Management (IWRM).