From introduction: In July 1977, the South Dakota Geological Survey and the U.S. Geological Survey began a 4-year study to evaluate the water resources and geology of Hanson and Davison Counties. The purpose of this report is to provide hydrogeologic information for future water development and planning in the counties. This study is part of an evaluation of the water resources and geology of eastern South Dakota (fig. 1).

From objectives and scope: The objectives of this study were to more accurately define certain hydrologic and hydraulic characteristics of the James River and its tributaries in South Dakota, to analyze the water budget and water quality within the Sand Lake National Wildlife Refuge, and to identify the need for additional studies.

From purpose and approach of study: The purpose of this study was to use the digital-computer model developed from the previous study (Koch, 1982) to examine the effects on the aquifer of a pumping rate of 25 million gallons a day under the worst-drought conditions that occurred during 1974-78. A frequency rating was determined for the most severe low-flow condition in the Big Sioux River.

From introduction: The overall purpose of this study were twofold: (1) To determine where greatest yielding wells at shallowest depths would produce water of suitable quality for municipal and industrial supplies; and (2) to determine regional effects of additional water development on the hydrologic system.

From introduction: This report describes the results of 1980 sampling of ground-water pumpage for irrigation on the High Plains, one phase of the High Plains Regional Aquifer-System Analysis project. These data were collected to estimate the volume of irrigation water pumped during 1980 and to determine current trends in irrigation pumpage on the High Plains.

Purpose: The objectives of this study were (1) to collect, synthesize, and interpret geologic and hydrologic data on the aquifer in the southern South Dakota area; (2) to evaluate, by digital-computer-model simulation, values assigned to the aquifer parameters; and (3) to evaluate the sensitivity of the calibrated digital-computer-model to changes in magnitude of the selected hydrologic parameters. Results of this study are, therefore, applicable to solving potential water-resource management problems in the southern South Dakota and northern Nebraska model area.