The U.S. Geological Survey, in cooperation with the Papio-Missouri River Natural Resources District (PMRNRD), conducted this study to map the water-level altitude of 2009 within the Elkhorn River Valley, Missouri River Valley, and Platte River Valley alluvial aquifers; to present the predevelop-ment potentiometric-surface altitude within the Dakota aqui-fer; and to describe the age and quality of groundwater in the five principal aquifers of the PMRNRD in eastern Nebraska using data collected from 1992 to 2009. In addition, implica-tions of alternatives to the current PMRNRD groundwater-quality monitoring approach are discussed.