The Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI), through its Hydrologic Information Systems project has developed Water Data Services (WDS) to fundamentally change the way in which scientists discover and utilize a broad range of water resources data. The goal of the project is to develop a suite of software tools to enable scientists to access more and better data for testing hypotheses and for analysis. The three components of the system include the development of Observations Data Model (ODM), a standardized database schema for point time-series data; WaterOneFlow, a set of query commands for accessing data through web services; and Hydrotagger, a semantic mapping system that provides crosswalking services for semantic mediation of data, metatadata and the transmission of data from multiple sources in a standardized WaterML format. Together these components support the confederation of water data from disparate sources into a distributed database that appears seamless to the user.