Water literacy is a key outcome for learners of all ages, who should understand how water interacts with both natural and human systems to participate in informed decision-making and support effective water management. It is therefore crucial to foster water literacy in today's global citizens, particularly through formal education. The purpose of this research is to examine K-12 water-related standards for teaching and learning from an array of disciplines to develop a comprehensive and transdisciplinary perspective on water education. We ask, "What do disciplinary standards specify as outcomes for students' learning about water?" Our research questions are: i) "To what extent do water-related standards address recognized domains of learning?", and ii) "What thematic outcomes for students' learning are apparent across grades in water-related standards?".The theoretical framework builds upon the importance of both the cognitive and affective domains in developing students' science-based understanding of concepts and skills conducive to responsible attitudes and behaviors. The study uses chi-square statistics and a conventional qualitative content analysis complemented by processes from grounded theory to analyze water-related education standards (n=477) from 12 education-oriented, non-governmental organizations mostly based in the United States. First, water-related standards emphasize the cognitive domain, including declarative and procedural knowledge for water-related concepts and skills. Although the affective domain and its social and emotional components are less prevalent, they are also key for students' learning to help them support water management. Second, the water-related standards illustrate two categories and nine sub-categories which encompass natural and human dimensions of water spanning K-12 grade bands. These results can help inform teaching and learning to cultivate water literacy, including curriculum development and classroom pedagogy.