This report examines and describes the geohydrologic status of the Albin and La Grange areas, specifically focusing on the use of irrigation wells to access ground water. Includes maps and illustrations.

Abstract: ^ digital computer model was used to model an unconfined sandstone aquifer (Arikaree aquifer) in about 340 square miles (880 square kilometers) in southeastern Wyoming. The model was calibrated by comparing observed and calculated changes in the potentiometric surface and leakage from the aquifer along streams during water year 1974. The comparison was fairly good for changes in the potentiometric surface and was good for leakage. The calibrated model was used to predict changes in the potentiometric surface and leakage through water year 1979, assuming no new ground-water development after 1974 and normal recharge to the aquifer. Water-level declines of as much as 14 feet (4.3 meters) were predicted, but much of the area would be relatively unaffected. The total predicted decrease in leakage between water years 1974 and 1979 was about 500 acre-feet (0.6 cubic hectometer) per year; the greatest decrease was predicted along streams closest to areas of pumpage.

Report and Geographic Survey. Report reveals "relations for estimating peak flows and mean annual flow for natural streams in Wyoming using the channel-geometry method and basin-characteristics method. Also includes maps, graphs, and photographs.

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.