How can you slow down water and prevent erosion or scour in a channel or ditch on your project?
Implementing effective best management practices (BMPs) to reduce the velocity of water in channels and ditches should be considered during construction activities to reduce the potential for erosion and scour which can result in polluted discharges.
A check dam is a temporary device placed across channels and ditches to reduce scour and erosion by reducing flow velocity and promoting sedimentation. Temporary check dams may be made with a variety of different products including stones/rocks and fiber logs.
Consider the following when installing temporary check dams in channels or ditches:
- Drainage area discharging to open channels shall not exceed 10 acres.
- Ensure proper spacing between check dams: top of downstream check dam should be the same elevation as the toe of the upstream check dam.
- Use check dams in combination with other BMPs, including rolled erosion control products (RECPs) such as erosion control blankets (ECBs), to prevent erosion and promote sedimentation.
Inspection and maintenance of temporary check dams should include regular inspections of the channel or ditches and removing accumulated sediment from behind the check dams when the depth reaches one-half the sump depth.
As the rainy season nears, be sure to think about how storm water will be conveyed on your construction site. Consider the types of BMPs that you can implement to prevent erosion and capture sediment and ultimately minimize pollutants discharged in storm water.