Excerpt from Geomorphic Stability of Sandbar 43. 1l on the Colorado River in the Grand Canyon in Response to Ground Water Seepage During Fluctuating Flow Releases From Glen Canyon Dam The Colorado River riparian zone and its associated resources in the Grand Canyon are influenced by the operation of Glen Canyon Dam. The'dam was constructed for several reasons, but primarily for flood control and water storage for Arizona, California and Nevada, as well as hydroelectric generation. The hydroelectric capability is designed to provide peak power generation during daily peak electrical demands. Consequently, the release of water from the dam fluctuates with power demand, and a daily surge of water continues downstream through the entire length of the Grand Canyon. Water levels in the river have fluctuated in narrow parts of the canyon as much as 4 meters in one day. A more typical fluctuation is from 1 to 3 meters. Interrelated processes occurring between the river and its riparian areas are affected by the fluctuation. This report describes the relationship of bank stored ground water to sandbar erosion occurring during fluctuating Colorado River flows. The Colorado River below Glen Canyon Dam is within both Glen Canyon nra and Grand Canyon np. Nps concerns include the preservation of sandbars along the Colorado River. These sandbars have high natural resources value and are used as camping sites by park visitors floating down the river. The terms sandbars, alluvial sand deposits, selected alluvial deposits, and sediment deposits, have been used to describe what are colloquially called beaches. In this report, the term sandbar will be used to be consistent with recent reports of other investigators. The purpose of this report is to evaluate and demonstrate the role of ground water on sandbar erosion observed at Sandbar 43.1l during daily fluctuations of the Colorado River. The objectives are: 1) to confirm that ground water is a contributing factor to erosion; 2) to quantify sandbar erosion rates directly associated with ground water seepage from the sandbar; and 3) present a hypothesis of ground water related processes contributing to sandbar erosion. 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.