For our projects, we try to obtain a 2-to-1 slope when re-grading. This means that for every two-foot run (distance back from the streambank), there is only a one-foot rise vertically from the stream. In other words, a 30 degree angle of the bank should be seen when looking at the bank from the side. To ensure that no soil goes tumbling into the stream during this step, lay some erosion control (EC) blanket or a coconut fiber log across the stream to prevent soil from washing away and filling in downstream areas. Any extra soil is evenly spread behind the newly re-graded area.
This new slope helps to mimic a natural slope. This slope is more conducive to reducing friction due to water flow and therefore decreases erosion and downstream sedimentation.
