Water plays an important role in creating the landforms found on Earth's surface. Moving water can remove and transport, or erode, pieces of rock, or sediments from their original location. These eroded sediments are pushed by the moving water, sometimes for only a few millimeters. Where the sediments end up coming to rest, or deposited, depends on the size of the sediments and the force of the flowing water. Sediments are deposited in those location where the force of the flow becomes too low to push the sediments any further. A delta is a depositional area near the mouth of a river, where the flowing river enters a non-flowing body of water such as a lake or ocean.