Book excerpt: Excerpt from Shallow Ground-Water Quality of Selected Land-Use/Aquifer Settings in the South Platte River Basin, Colorado and Nebraska, 1993-95 Shallow ground-water resources are an impor tant source of fresh water in much of the semiarid Western United States where surface-water supplies are limited. In the South Platte River Basin of Colorado, Nebraska, and Wyoming (fig. Extensive agricultural activities and high rates of rural and metropolitan population growth result in increased demand for development of ground-water resources. Shallow ground water (generally less than 100 it deep) is particularly valuable because it is relatively easy to withdraw. Shallow ground water also generally is of better quality (fewer dissolved constituents) than deeper water supplies in buried aquifers. The primary shallow aquifers in the South Platte River Basin are the fractured crystalline bedrock of Precambrian age exposed in the mountainous western part of the basin and the alluvial deposits on the eastern plains, which fill the present and historic riverbed channels. These two aquifers supply more than 95 percent of the ground water used in the South Platte River Basin (litke, Water withdrawn from the crystalline bedrock aquifer primarily is used for domestic drinking water. Most of the water with drawn from the alluvial aquifer is used for agricultural irrigation, and drinking water is a minor use. However, water levels are declining in parts of the deeper drinking-water aquifers under the plains (robson, and the alluvial aquifer may become a future drinking-water supply in this part of the basin. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.