Little empirical research has been done to support policies that increase access to free drinking water as part of comprehensive strategies to reduce consumption of sugary beverages and prevent childhood obesity. This study will examine beverage environments in 20 diverse high schools in King County, Wash., to guide the development of effective school water policies by providing evidence on specific aspects of school water access and student water/sugary beverage consumption at school and on the feasibility of implementing school policies to improve water access. Study aims are to: 1) describe the sources and types of water and sugary beverages that are available to high school students while they are on school campuses, including water quality characteristics related to water appearance, temperature, flow, and maintenance of school water access points; 2) develop, test, and implement a protocol to sample and assess student water consumption and sugary beverage consumption at school; 3) determine associations between students’ access and consumption at school and the degree to which these vary by school demographics, including race/ethnicity and income; and 4) explore the perceptions of school administrators about access to water and potential policy and environmental changes that could be made to improve water access.