Which term is used to describe a layer of material used to prevent erosion and manage water flow?

Rip Rap is the correct term used to describe a layer of material, typically composed of large stones or boulders, that is placed on slopes or along shorelines to protect against erosion and to manage water flow. Its weight and rough texture help to stabilize soil and prevent it from being washed away by water, making it an effective solution in various civil engineering and environmental projects.

While other terms like geogrid, retaining layer, and filter fabric refer to different types of materials or functions in erosion control or structural support, they do not specifically represent the same protective characteristics as rip rap. Geogrids are primarily used to reinforce soil and provide structural support in various applications, and filter fabric aids in drainage and prevents soil from washing away while allowing water to pass through. A retaining layer is more generally related to structures designed to hold back soil and does not specifically target erosion prevention in the same manner as rip rap.