What is the function of grade control in a stream?

Grade control in a stream plays a crucial role in managing the streambed's elevation and ensuring stability within the water flow. The primary function of grade control is indeed to separate abrupt changes in the grade of the streambed. This is important because such changes can lead to erosion or sediment deposition, which can dramatically alter the stream's flow dynamics and ecosystem health.

By providing structure to the streambed configuration, grade control structures, such as check dams or weirs, create stable points that help maintain a consistent gradient. This stabilization is essential for preventing the downstream movement of sediment and maintaining adequate habitat for aquatic life. In summary, the proper functioning of grade control ensures that the stream remains healthy and accessible, while minimizing the risk of erosion and other negative impacts associated with abrupt changes in elevation.