Planning and Implementing Erosion and Sediment Control Practices
The best management practices for runoff control may include:
Diversions are used in areas where runoff from areas of higher elevation poses a threat of property damage or erosion.
Preserving Natural Vegetation
Preservation of natural vegetation is applicable to all construction sites where vegetation exists in predevelopment condition. Only land needed for building activities and vehicle traffic needs to be cleared.
Stabilizing entrances to a construction site is to minimize the amount of sediment leaving the site as mud and sediment attached to motorized vehicles.
Check dams should be used in swales or channels where it is not practical to line the channel or implement other flow control practices.
A gravel or stone filter berm is used for temporary runoff diversion and sediment control.
Grassed channels should be used in areas where erosion resistant conveyances are needed, including areas with highly erosive soils and moderately steep slopes.
Riprap can be used to stabilize cut and fill slopes; channel side slopes and bottoms; inlet and outlets for culverts, bridges, slope drains, grade stabilization structures, and storm drains; and stream banks and grades.
The best management practices for erosion control may include:
Chemical stabilizers, also known as soil binders or soil palliatives, provide temporary soil stabilization. Chemical stabilization can be used in areas where other methods of stabilization such as temporary seeding or permanent vegetation are not effective because of environmental constraints.
Mulching can provide immediate effective, and inexpensive erosion control. Mulching can be used in areas where temporary seeding cannot be used because of environmental constraints.
Permanent seeding can be used on roughly graded areas that will not be re-graded for at least a year. Vegetation controls erosion by protecting bare soil surfaces from displacement by raindrop impact and by reducing the velocity and quantity of overland flow.
Sodding is appropriate for any graded or cleared area that might erode, requiring immediate vegetative cover. Sodding eliminates the need for seeding and mulching and produces more reliable results with less maintenance.
Soil roughening is appropriate for all slopes. Rough slope surfaces are preferred because they aid the establishment of vegetation, improve infiltration, and decrease runoff velocity.
Geotextiles can be used alone for erosion control. Geotextiles can be used as matting, which is used to stabilize the flow of channels or swales or to protect seeding on recently planted slopes until they become established.
Reinforced soil retaining structures should be used when sites have very steep slopes or loose, highly erodible soils that cause other methods such as chemical or vegetative stabilization or regarding, to be ineffective.
Vegetative buffers can be used in any area that is able to support vegetation, but they are most effective and beneficial on floodplains, near wetlands, along stream banks and on steep, unstable slopes. They are also effective in protecting wetlands or water bodies by displacing activities that might be potential sources of non-point source pollution.
The best management practices for sediment control may include:
Temporary Diversion Dikes, Earth Dikes and Interceptor Dikes
Earth dikes are an effective means of diverting sediment-laden storm water runoff around a disturbed area. Diversion dikes should be constructed and fully stabilized prior to commencement of major land disturbance. This will maximize the effectiveness of the diversion measure as an erosion and sediment control device.
Wind Fences and Sand Fences
Wind fences are applicable to areas with a preponderance of loose, fine textured soils that can be transported off-site by high winds. They are especially advantageous for construction sites with large areas of cleared land or in arid regions where blowing sand and dust are especially problematic.
Brush barriers are acceptable to use as a perimeter sediment control structure, used to prevent soil in storm water runoff from leaving a construction site.
Silt fences are applicable to construction sites with relatively small drainage areas. Silt fences can be used as temporary perimeter control around sites where there will be soil disturbances due to construction activities.
Sediment Basins and Rock Dams
Sediment basins and rock dams are two ways to capture sediment from storm water runoff before it leaves a construction site. Sediment basins are usually used for drainage areas of 5 to 100 acres. They can be temporary or permanent structures.
Other best management practices required by the general permit:
- Sediment filters
- Sediment chambers
- Sediment trap
- Storm drain inlet protection
- Construction site waste management
- Spill prevention
- Vehicle maintenance and washing areas