Caution: The information on this page is from the original Minnesota Stormwater Manual (2005). For updated information on construction stormwater best management practices we recommend the following links.

Temporary construction erosion and sediment control is the practice of preventing or reducing the movement of sediment from a site during construction through the implementation of man-made structures, land management techniques, or natural processes. This page does not contain detail on the use of specific BMPs but instead merely discusses their use and refers the reader to other useful resources for detail.

photo showing an example of a vegetated buffer
An example of a vegetated buffer adjacent to a construction site.

Introduction

Temporary construction erosion and sediment control limits the amount of sediment that is carried into lakes, streams and rivers by storm water runoff. Sediment carries nutrients and pollutants that degrade water resources and harm aquatic wildlife. Proper planning of construction site activities greatly reduces the impact of soil disturbance activities on nearby resources and diminishes the need for costly restorations. A construction plan that limits sediment disturbance in potential problem areas and uses effective temporary sediment control practices will lessen negative impacts to local water resources and natural areas.

Planning

To establish a construction plan that will minimize sediment movement, designers will need information on existing site conditions and neighboring resources that require special consideration including water bodies, natural areas, bluffs and other highly erodible or sensitive areas. Construction activities should be designed in a manner that minimizes overall soil disturbance and phases areas of disturbance such that the amount of land disturbed at any one time is reduced. This type of planning will limit the need for larger structural sediment control solutions. Additionally, the designer should determine which local, state, and federal agencies require permits for the type of work planned. The site plan will need to account for the requirements of all agencies issuing permits.

Permits

Projects disturbing 1 acre or more of land or a common plan of development or sale that disturbs greater than 1 acre will require a National Pollutant Discharge Elimination System (NPDES) Construction Stormwater Permit from the Minnesota Pollution Control Agency (MPCA). The size threshold can be smaller if the site is a part of a “common plan of development or sale” and if the larger common plan will ultimately disturb more than 1 acre. The permit requires the establishment of a Stormwater Pollution Prevention Plan (SWPPP) for the construction site.

Other Minnesota agencies requiring permits typically might include watersheds, municipalities, and soil and water conservation districts.

photo showing a construction site with no sediment control practices
Example of a construction site with no sediment control practicesr
photo showing a construction site with sediment control practices
Example of a construction site with sediment control practices

Sequencing activities

The practices included in the site plan and SWPPP will need to control runoff, stabilize slopes and exposed soils, and limit the movement of soils into drainage systems and natural areas. A key factor in accomplishing these goals is the sequencing of construction activities such that the minimum possible area is disturbed at any one time. Initial site work should include establishing protective buffer zones adjacent to onsite resources that require protection and setting up perimeter sediment controls.

During the course of construction, a variety of erosion prevention and sediment control practices may be necessary in order to stabilize slopes and drainageways, protect inlets to the storm water conveyance system, limit gully formation, and capture sediment. Several practices can be used as temporary erosion and sediment control practices and these can be used to meet NPDES requirements. Temporary seeding is not erosion protection or sediment control until vegetation is established or until the area is protected with an erosion control blanket. Projects that are actively under construction in winter/frozen months should include additional inspection and clean-up activities. Temporary sediment basins should be sized to include extra storage for snowmelt.

Inspection and maintenance

A final key element to ensure effectiveness of the erosion and sediment control plan is the implementation of an inspection and maintenance program. Frequent inspection and maintenance activities ensure that the installed temporary sediment control practices are operating effectively throughout the course of the project.

Overview of temporary sediment control practices

photo illustrating a vegetated buffer
Photo illustrating a vegetated buffer
  • Vegetated Buffers
    • Uses: erosion control
    • Areas to Use
      • Perimeter
      • Slopes
      • Drainageways
      • Around Trees, Water Bodies, Natural Areas
    • Method: Vegetated buffers are areas designated to remain undisturbed in order to protect trees, lakes, bluffs, or natural areas. Buffers should be marked and maintained around all resources requiring protection.
photo illustrating a silt fence
Photo illustrating a silt fence
  • Silt Fence
    • Uses: sediment control
    • Areas to Use
      • Perimeter
      • Slopes
      • Drainageways
      • Other: Drainage System Inlets
    • Method: Silt fence filters sediment from runoff by allowing water to pass through a geotextile fabric or by creating a pool to allow sediment to drop out of the water column. Silt fence is installed primarily at downslope boundaries of the work area but can also be used for inlet protection, and around the perimeter of stockpiles
photo illustrating a silt fence
Photo illustrating a fiber log
  • Fiber Log
    • Areas to Use
      • Sediment Control
      • Perimeter
      • Slopes
      • Drainageways
      • Other
        • Drainage System Inlets
    • Method
      • Fiber logs include straw, wood, or coconut fiber logs, compost logs, and rock logs that slow water and filter sediment. Fiber logs are used for inlet protection, ditch checks, and as perimeter control where silt fence is infeasible.
photo illustrating a Rock Construction Entrance
Photo illustrating a rock construction entrance
  • Rock Construction Entrance
    • Areas to Use
      • Sediment Control
      • Perimeter
    • Method
      • A rock construction entrance is a bed of rocks that helps to remove sediment from vehicle tires. Rock construction entrances should be placed at all site access points. The use of 1 1/2 inch – 3 inch clear aggregate is recommended. Periodic cleaning or replacement is recommended
  • Grade Breaks
    • Areas to Use
      • Sediment Control
      • Slopes
    • Method
      • Grade breaks are changes in slope that break up concentrated flow, preventing the formation of gullies. Grade breaks should be incorporated into long slopes
photo illustrating Grade Breaks
Photo illustrating temporary seeding
  • Temporary Seeding
    • Areas to Use
      • Erosion Protection
      • Sediment Control
      • Perimeter
      • Slopes
      • Drainageways
    • Method
      • Temporary seeding allows plants to stabilize the soil through vegetation and root growth. A large variety of plants are available for temporary seeding of different conditions; the most common are rye grass, winter wheat, and oats.
photo illustrating Grade Breaks
Photo illustrating an erosion control blanket
  • Erosion Control Blanket
    • Areas to Use
      • Erosion Protection
      • Sediment Control
      • Perimeter
      • Slopes
      • Drainageways
    • Method
      • Erosion control blanket is a mat made of netting layered with straw, wood, coconut or man-made fibers that prevents erosion by sheltering the soil from rainfall and runoff while holding moisture for establishing plants. Blankets are installed in channels
photo illustrating Grade Breaks
Photo illustrating mulch
  • Mulch
    • Areas to Use
      • Erosion Protection
      • Slopes
    • Method
      • Mulch is wood fibers, compost, wood chips, straw, or hay that is applied as a cover to disturbed soil. Mulch reduces erosion by absorbing energy from rainfall and runoff and provides protection and moisture for the establishment of vegetation, when properly disc anchored or spread.
photo illustrating Hydraulic Mulch
Photo illustrating hydraulic mulch
  • Hydraulic Mulch
    • Areas to Use
      • Erosion Protection
      • Slopes
    • Method
      • Hydraulic mulches for erosion control are typically comprised of wood fibers and are applied by hydroseeding equipment. Hydraulic mulches are typically used in areas with steeper slopes or where equipment access would be difficult.
photo illustrating Temporary Pipe Downdrains
Photo illustrating temporary down drains
  • Temporary Pipe Downdrains
    • Areas to Use
      • Erosion Protection
      • Slopes
    • Method
      • A temporary pipe downdrain conveys runoff down slopes in a pipe so that runoff will not cause erosion. Pipe downdrains are installed where concentrated flow would drain onto a disturbed slope
photo illustrating Temporary Pipe Downdrains
Photo illustrating floatation silt curtain
  • Floatation Silt Curtain
    • Areas to Use
      • Sediment Control
      • Other
        • Lakes, Wetlands, Streams
    • Method
      • Floatation silt curtain is fabric fence installed in water bodies to contain sediment near the banks of the work area. Must be used in conjunction with other sediment control techniques
photo illustrating Temporary Pipe Downdrains
Photo illustrating rock bags
  • Rock or Compost Bags
    • Areas to Use
      • Sediment Control
      • Slopes
      • Other
        • Drainage System Inlets
    • Method
      • Rock and compost bags are filled bags that are used to filter water, control ditch grade, or to provide inlet protection
photo illustrating Temporary Pipe Downdrains
Photo illustrating rock check dam
  • Rock Check Dam
    • Areas to Use
      • Sediment Control
      • Drainageways
    • Method
      • Rock check dams are rocks piled across a ditch to slow flows and capture sediment. Rock checks are installed perpendicular to flow and should be wide enough to ensure that flow remains in the center.
photo illustrating Riprap
Photo illustrating riprap
  • Riprap
    • Areas to Use
      • Erosion Protection
      • Other
        • Drainage System Inlets
    • Method
      • Riprap is appropriately sized rocks that reduce the energy of fast moving flows. Riprap is used along channels and at outfalls
photo illustrating a Temporary Sedimentation Basin
Photo illustrating rock check dam
  • Temporary Sedimentation Basin
    • Areas to Use
      • Sediment Control
      • Other
        • Throughout Site
    • Method
      • Temporary sedimentation basins are depressions that capture runoff to slow the flow of water and allow sediment to settle out
photo illustrating a Temporary Sedimentation Basin
Photo illustrating filter bag
  • Filter Bag
    • Areas to Use
      • Sediment Control
      • Other
        • Drainage System Inlets
    • Method
      • Filter bags are mesh bags that capture sediment but allow water to pass through. Filter bags are installed in storm drain inlets.

References

This page was last modified on 11 February 2019, at 08:32.

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