What Are the Costs and Benefits of Damming a River?
ESU401  An Artificial Flood

Downstream from the dam, sand beaches were eroding away and plants were crowding available sandbars and canyon walls in the Grand Canyon. Scientists who were concerned about these changes in the river environment suggested that an artificial flood from the dam might reverse some of the changes.

In the spring of 1996, the dam released more than double its normal water flow for about a week to simulate a natural flood. Results of the artificial flood are still being monitored. Examine the images from before, during, and after the simulated flood to see some of the changes.

  !   Click each image to see a larger view.

6. Describe the importance of annual floods to canyon flora and fauna.

Consider the overall impact of Glen Canyon Dam on the water that flows through the Grand Canyon. In the chart on your student answer sheet, use a scale from -2 to +2 to indicate your evaluation of the dam's impact on water downstream from the dam.

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