There were many reasons for the erosion of the outer bank of the rivers. The power of the water is one of the main causes for the outer bank erosion. The energy generated by the rivers while traveling is great. Events like flooding can dramatically increase the flow of the water. Another reason for the erosion is the gravity. In some cases, piping or increase of water table is also a known cause for the erosion of the outer banks. Erosion occurs when the current velocity and turbulence of the water is more than the soil particles and its cohesive strength. The erosion of the outer banks of the river can cause a meandering and widening its valley. The size of the river may take snake pattern, as the eroding outer bank sediments are deposited inside. The speed of the river is greater at the outer bank than the inner bank as there is less friction and it increases energy of the river. The slope failure occurs when the materials that consisted in the bank are no longer able to withstand the forces of gravity. The erosion also affects the river bed and it increases the height of the bank. The result is that the soil is unable to withstand the force which is holding it together. The various parts of the bank especially, the top, cracks and its different sections begins to slide downwards. The force of the river is very strong that it will loosen rocks and soil on the river bed and banks. The pressure is especially exerted on the bends. Gradually, it wears banks and weakens it. This process is known as the hydraulic action. During the flow of river, the rocks and pebbles smash together and form into small particles. This is known as attrition. On the process of flow, the soluble particles or minerals like chalks and limestone are dissolved into the water. This is due to the presence of acid in the river water. This process is known as solution or corrosion. Large pieces of load through the river like rocks can weary down the river bed. This is called as abrasion or corrasion. As the river transport materials, fine materials such as clay, silt and fine sand are carried along the water. This process is known as suspension. During the time of flood, when the current is strong, large rocks and boulders are pushed through the river bed. This process is known as traction.