The Water Data Exchange (WaDE) is a project initiated by the member states of the Western States Water Council (WSWC), in cooperation with the Western Governors' Association (WGA), to assist state water agencies when answering local, regional, and national water availability questions. WaDE provides requested information more easily, sustainably, and cost-effectively, by streamlining the publication of water planning, use, and allocation data for access by planners, policy makers, and the public. This paper presents the background of the WaDE project, how it was envisioned to function, the types of data it will provide, and why access to the information is important for water managers. The goals of WaDE include the establishment of a governance structure, documentation of the current state agency capabilities and methodologies, and the design of a common data format that targets water data products and/or water-quantity information. Many of these foundational products have been developed, such as governance workgroups, databases, web services code, and a prototype mapping application for centralized access. A major milestone, still underway, is the distribution and deployment of the databases and web services code within member states' information technology environments. Lastly, WaDE seeks to encourage the publication of other agency datasets using web services and standardized data formats. [ABSTRACT FROM AUTHOR]