Erosion control best management practices are required during all ground disturbing activity until permanent site ground covers are in place. A best management practice (BMP) is a physical, chemical, structural or managerial practice that prevents, reduces or treats contamination of water or which prevents or reduces soil erosion.
Instream BMPs are designed to provide sediment trapping for projects that must take place within the waterway. Projects that cross or otherwise work within the waterway should strive to limit the amount of work that occurs within the waterflow line. Measures that can reduce the amount of instream work needed include work from bank areas, stream diversion around work areas or scheduling for seasons of no limited flows.
Instream BMPs are:
- Instream Sediment Trapping Devices
Instream sediment trapping devices include both floating materials anchored to the watercourse bottom and instream sediment collection mats that run along the watercourse bottom. These materials are specifically designed to limit sediment transport impacts within the body of water.
- Provide sedimentation protection for in-stream, bank or upslope ground disturbance or form dredging or filling within a waterway