Lake Mead (image) University of Texas at Austin Share Print E-Mail Caption The Colorado River supplies water to Lake Mead, the largest man-made reservoir in terms of capacity in the United States. New research from The University of Texas at Austin has found natural variability, not humans, have the most impact on water stored in the river and the sources that feed it. Credit U.S. Geological Survey Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.