A data management system (DMS) was developed, tested and demonstrated to store and manage water quality and quantity (WQ2) data pertaining to U.S. Environmental Protection Agency/Office of Research and Development (EPA/ORD) research projects in standardized formats. This approach was taken to facilitate accessibility, sharing, integration, and use of this information for simple calculations and inclusion into models by EPA and other users to inform water management decisions. The objectives of this project were: (1) Build a previously identified hydrologic information system (HIS) Observational Data Model (ODM) and convert existing water quality and quantity data, generated by EPA/ORD-research projects, into this format; (2) Develop, test and demonstrate a scalable DMS based on HIS protocols for storage and management of geo-referenced data; and (3) Enable targeted users to access, exchange and integrate geospatially referenced WQ2 information, and to conduct relatively simple calculations and/or run models to inform water management decisions at various watershed scales. The HIS developed by the Consortium of Universities for the Advancement of Hydrologic Science Inc. (CUAHSI) was used in this project. The CUAHSI HIS ODM model is widely accepted in the United States, is compatible with the National Water Quality Portal, and is gaining international acceptance as the standard for water data. This HIS is web-based, and uses the WaterML format for sharing hydrologic time series data.