The report describes the procedures used to select, retrieve, compile, and screen a lake and reservoir data base from the STORET (STOrage and RETrieval) system of the U.S. Environmental Protection Agency. Procedures used to select, compile, and screen the size of the data base also are discussed. The retrieved data comprise 116 water-quality and biological constituents and physical and morphometric factors commonly used to assess the limnology and water quality of lakes and reservoirs.