Chapter 13, Problem 1CR

To determine

The importance of the Colorado River basin in the United States and the way in which human activities are stressing this system. The definition of drought and the way in which it has affected the Colorado River system.

Answer to Problem 1CR

The Colorado River is very important for the United States as dam-reservoir systems built associated with the river provide irrigation water, drinking water, and electricity necessary for the nation. In the absence of this river, many cities of the states of the United States would have become deserts. Drought represents a prolonged period during which the rate of evaporation becomes higher and rate of precipitation becomes lower than the normal rate. The drought faced by the Colorado River 1999 has affected the entire plumbing system built on the river. The river started to shrink due to such a condition and lost much of its water.

Explanation of Solution

The Colorado River forms the principal river of the arid southwestern United States and it flows for about 2,300 kilometers along 7 states of the Gulf of California. The snow-covered mountain top of the Rocky Mountains form the water source of this river.

For the past hundred years, this river has been restrained by a huge water system including 14 important dams and reservoirs and canals that transport water to farmers, industries, ranchers, and cities. Such dam and reservoir systems generate electricity for about 40 million people in seven states of the United States through hydroelectric plants built associated with them.

The water system becomes a source of irrigation water that is used for producing nearly 15 percent of the livestock and crops of the nation. About 90 percent of the drinking water for Las Vegas, Nevada is provided from this plumbing system. Moreover, large quantities of the water utilized in Arizona, Phoenix, and San Diego and Los Angeles, California are also from the dam-reservoir system of the Colorado River. In the absence of such a system, all these cities would have turned out to be uninhabitable deserts regions.

Massive quantities of water have been drawn out from the Colorado River for crop cultivation and for supporting cities with arid climates. In addition, the river system is facing intense drought since 1999 that makes the conditions worse. Drought can be defined as a long period, often a season or more, with the rate of precipitation reaching levels lower than normal and the rate of evaporation reaching levels higher than normal. Due to the drought, during 2015, Lake Mead dropped to a record low water level.

The overuse of the Colorado River demonstrates the challenges encountered by people and governments residing in arid and semiarid areas depending on shared river systems. In the arid-water scarce regions, population explosion and economic growth have placed increasing demands on limited or declining supplies of surface water. According to many experts, water scarcity is going to the major environmental concern for the upcoming centuries.