What is the recommended slope percentage over which slopes should be terraced to prevent erosion?

The recommended slope percentage over which slopes should be terraced to prevent erosion is typically around 50%. Terracing is an effective technique to reduce soil erosion on steep slopes by breaking the slope's length and allowing for the retention of water and soil, which minimizes runoff and promotes vegetation growth.

When slopes exceed this critical percentage, the risk of soil erosion dramatically increases due to the force of gravity, leading to faster water runoff that can disrupt soil stability and cause erosion. Terracing helps create flat surfaces on which water can infiltrate more easily instead of flowing directly down the slope, which can wash away topsoil.

Understanding this threshold is crucial in landscape architecture and site design, as it directly affects the stability and sustainability of the land design. Thus, recognizing that slopes of 50% or greater require terracing as a preservation method is essential for preventing soil erosion and managing landscape health.