Let the River Run

Things occur in nature, that we as humans sometimes prevent from occurring naturally.

For example - a dam on a river. Once put into use on a river, a dam simply stops or slows down the natural flow of the water. Sometimes this is for the better, however - sometimes, it is for the worse. This is the case in the Grand Canyon. Some rivers go through natural, periods of flooding and receding, at certain times of the year, or in occurrence with other geographical events. For the first time in thirty years, in March 1996, flood waters rages through the Grand Canyon. However, this was not the result of a natural flood. The

Colorado River would experience this same type of man made flood, naturally. These floods would occur every year during winter and spring rains. This water has been released from an upstream dam. The dam was put into action in 1963. Since then, years of environmental damage have been adding up. Dams have been on the river for nearly a century - however, none were upstream of the Grand Canyon until this one was built in

1963.

Rivers have a number of processes involved in their everyday activities that allow themselves and the land around them to flourish. When the flow of a river is disrupted, so are these processes. Rivers carry sediments. Along with carrying these sediments, they also deposit them, usually onto surrounding land areas. This deposition occurs when the flow of the water slows down. The amount of sediment a river is carrying generally gives color to it’s appearance. Before this dam was built, the Colorado River possessed a cloudy, rust color. Now, when the water is stopped at this dam, over 90 percent of it’s sediment is dropped. As a result - this gives the river a crystal clear appearance. Another result of the lack of sediment, is the beach erosion that is occurring. Some beaches have eroded to over half of their original size. This erosion is happening because the beaches depended on the annual floods to bring them a continuous supply of fresh, fine sand. The dam is trapping a majority of the sand. There are small tributary rivers that flow uninhibited into the Colorado River below the dam, they bring some sediment - but not enough. As well as these beaches depending on the floods - the rapids in the river, have this same type of dependence. Here, the floods would clear any debris from between the boulders, an area that is now choked.