This book provides new research on water resources. Chapter One discusses water resource management and intelligent monitoring systems for reservoirs. Chapter Two describes actions applied to the management of water resources in the region of La Plata in Argentina. Chapter Three analyses the physico-chemical characteristics of natural waters in a drainage system of northern Xinjiang (Central Asia) to provide additional information to the readers on the chemical evolution and recharge mechanism of natural waters in an arid environment. Chapter Four reviews flow alterations and then employs a modeling system and databases for the river systems of Texas to investigate characteristics of river flows and long-term impacts thereto resulting from development and other causative factors.