Moving water is the single most important erosional agent. Rain, waves, streams and rivers erode earth much more quickly than other erosional agents, such as wind and glaciers.
Water erosion creates gullies and valleys, sea cliffs, natural stone arches, braided riverbeds and deltas. It also continually transforms coast lines. One of the most recognizable results of water erosion is the Grand Canyon, which was slowly carved down by the Colorado River over more than 6 million years.
Not only is water a powerful erosional force, but it also covers 70 percent of the planet. Coupled with the amount of land that receives regular rainfall, water comes into contact with more earth than other erosion forces.