The Colorado River is the seventh longest river. In the 1920s, Western states began dividing the Colorado River's water by building dams and diverting the river's flow to San Diego, Phoenix, and other major cities in order to supply those cities with water. In the past, the river was known to be a major source of water and electricity. The Colorado River flows through Utah, Arizona, Colorado, Nevada, California, Baja California, and Sonora. Over the past decade, a drought has swept across the southwest, causing river levels to fall. The Colorado River still flows through the Grand Canyon. The river has a total length of 1,450 miles. The headwaters of the Colorado River are found in La Poudre Pass Lake in Rocky Mountain National Park, Colorado (“Colorado River Geography”). The delta of this river is located in the Gulf of California in Mexico; today, this delta is primarily dry due to water withdrawal for irrigation and urban uses (“Geography of the Colorado River”). Humans have lived around the Colorado River Basin for thousands of years. The river was first mentioned in documents in 1539 and first given the name Colorado in 1743 ("Geography of the Colorado River"). During the 1800s and 1900s, explorations of the river took place and in 1921 it was reamed from the Grand River to the Colorado River ("Geography of the Colorado River"). The flow of the Colorado River has created numerous canyons. One of the most remarkable canyons created is the Grand Canyon. Uses of the river include power generation, irrigation, municipal and industrial use, flood control, and recreation. This water is used by residents of the areas surrounding the river as it is diverted for their use. Part of the policy is middle of paper......groundwater collections ("Water returns to dry Colorado River"). The pulsating flow results in the rehabilitation of the river bed and the increase in the water level. The largest water quality problem in the Colorado River is salinity and selenium (“Water Availability: A Question of Quantity, Quality and Use”). These issues pose long-term threats such as water availability, effects on plant growth and crop yield, damage to infrastructure, reduction in water quality, and taste and taste issues. of odor (“Water availability: a question of quantity, quality and use”). To reduce this problem, federal agencies and states in the Colorado Basin are working together to implement salinity control projects to reduce the amount of salt entering the river; this process would save approximately $100 million in economic damages per year (“Water Availability: A Matter of Quantity, Quality and Use”).