From purpose and scope: There are two principal purposes for this study. The first is to describe the hydrogeologic system of the study area. The second is to develop and demonstrate a capability for evaluating, quantitatively, the effects of different management alternatives on water levels and on streamflow in the study area.

Abstract: This report lists the machine-readable data files developed for the Madison Limestone and Northern Great Plains Regional Aquifer System Analysis (RASA) projects that are stored on magnetic tape and available from the U.S. Geological Survey. Record format, file content, and size are given for: (1) Drill-stem-test data for Paleozoic and Mesozoic formations; (2) geologic data from the Madison Limestone project; (3) data sets used in the regional simulation model; (4) hydraulic-head data for the Lower and Upper Cretaceous aquifers; and (5) geologic data for Mesozoic formations of the Northern Great Plains.

From abstract: The High Plains Regional Aquifer System Analysis study has developed a regional water-resources (and related) data storage and retrieval system to organize and preserve areal interpretive data. The system is general and can easily be adapted for other studies. This report documents the High Plains data base as well as the general system that is independent of the High Plains area.

From introduction: This is the second report by U.S. Geological Survey personnel in Nebraska that presents interpretive information for the High Plains aquifer system in the State...This report and the first report are complementary; information from both can be used to compute certain aquifer properties, knowledge of which is essential in the development of a management plan for the aquifer system.

Abstract: A digital simulation model was used to analyze regional ground-water flow in the Madison Group aquifer in the Powder River Basin and adjacent areas. Most recharge to the aquifer originates in or near the outcrop areas of the Madison in the Bighorn Mountains and Black Hills , and most discharge occurs through springs and wells. Results from the model calculations indicate that the total flow through the aquifer in the modeled areas was approximately 200 cubic feet per second (5.7 cubic metres per second). The aquifer can probably sustain increased ground-water withdrawals probably would significantly lower the potentiometric surface in the Madison aquifer in a large part of the basin. The digital model could better predict the effects of withdrawals if more accurate estimates of the storage coefficient, transmissivity, and leakance could be obtained.

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.