PREFACE

The collection of surface-water data is a major activity of the U.S. Geological Survey's (USGS) Water Resources Division (WRD). Approximately $40 million was spent in 1982 by WRD in cooperation with State and local governments and other Federal agencies in the collection of these data. This major expenditure of funds for hydrologic data collection should be evaluated periodically with respect to the needs of the data users and the utility of the data. It is essential that a rigorous analysis be made of the stream-gaging program to assure maximum cost-effectiveness. The USGS is undertaking a nationwide analysis of its stream-gaging program over a 5-year period. The results from such an analysis should satisfy both local and national water-data needs within budget constraints while maintaining quality control. This report for the State of Virginia is one in a series of statewide reports describing this analysis. The techniques and methods being utilized in the nation-wide analysis are described and documented in this report as applied to the Virginia stream-gaging program. Analysis of the stream-gaging program is designed to define and documen