South Carolina Forestry Commission
Best Management Practices

BMP Graphic

Forest Road Construction

BMPs: Planning , Construction , Stabilization , Maintenance
Avoid
Forested Wetland Road Construction

An effort has been made to italicize technical words or phrases and clearly define them in the glossary.

Forest roads are needed to provide access for forest management and recreational activities. Permanent main access (MA) roads and temporary limited use (LU) roads should be planned in advance of road construction in order to protect water quality.
Historically, roads have been one of the major sources of sediment from forestry related activities. Planning can reduce skidding distances and eliminate unnecessary roads. Use of broad-based dips, water bars, filter strips, and other sediment control techniques can significantly lower the amount of erosion which might otherwise occur.

To protect water quality, roads should be designed to minimize the amount of sediment entering stream channels.


Figure 4. Culverts provide cross drainage for roads with inside ditches.

BMPs

Planning

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BMPs

Construction

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Turnout Graphic
Figure 5. Water turnouts empty road runoff onto the undisturbed forest floor.

Dips Graphic
Figure 6. Broad-based dips remove road runoff while allowing vehicles to maintain normal speeds.


BMPs

Stabilization

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BMPs

Maintenance

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Avoid

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Table 3: Recommended Maximum Spacing for Drainage Structures

Slope (Percent)Broad-Based Dips
and Culverts
(feet)
Water Bars
and Turnouts
(feet)
2 300 245
5 180 125
10 140 80
15 125 60
20 120 50
25 115 40

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Waterbars
Figure 7. Water bars are used to remove surface runoff when retiring limited use roads.

FORESTED WETLAND ROAD CONSTRUCTION

Road construction for silvicultural purposes in jurisdictional wetlands does not require a permit because of the silvicultural exemption under Section 404 of the Clean Water Act. However, to qualify for the silvicultural exemption, the road construction must comply with the following BMPs, (from Clean Water Section 404 Program Definition and Permit Exemption, Part 232.3).

Federally Mandated BMPs

  1. Permanent roads, temporary access roads, and skid trails in waters of the United States shall be held to the minimum feasible number, width, and total length consistent with the purpose of silvicultural operations and local topographic and climatic conditions.
  2. All roads, temporary or permanent, shall be located sufficiently far from streams or other water bodies (except for portions of such roads which must cross water bodies) to minimize discharges of dredged or fill material into waters of the United States.
  3. The road fill shall be bridged, culverted, or otherwise designed to prevent the restriction of expected flood flows.
  4. The fill shall be properly stabilized and maintained to prevent erosion during and following construction.
  5. Discharges of dredged or fill material into waters of the United States to construct a road fill shall be made in a manner that minimizes the encroachment of trucks, tractors, or other heavy equipment within the waters of the United States (including adjacent wetlands) that lie outside the lateral boundaries of the fill itself.
  6. In designing, constructing, and maintaining roads, vegetative disturbance in the waters of the United States shall be kept to a minimum.
  7. The design, construction, and maintenance of the road crossing shall not disrupt the migration or other movement of those species of aquatic life inhabiting the water body.
  8. Borrow material shall be taken from upland sources whenever feasible.
  9. The discharge shall not take, or jeopardize, the continued existence of a threatened or endangered species as defined under the Endangered Species Act, or adversely modify or destroy the critical habitat of such species.
  10. Discharges into breeding and nesting areas for migratory waterfowl, spawning areas, and wetlands shall be avoided if practical alternatives exist.
  11. The discharge shall not be located in the proximity of a public water supply intake.
  12. The discharge shall not occur in areas of concentrated shellfish production.
  13. The discharge shall not occur in a component of the National Wild and Scenic River System.
  14. The discharge of material shall consist of suitable material free from toxic pollutants in toxic amounts.
  15. All temporary fills shall be removed in their entirety and the area restored to its original elevation.

Additional BMPs are listed below as interpretation of the 15 federally mandated BMPs.

BMPs

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Contents
Streamside Management Zones / Stream Crossings / Timber Harvesting / Site Preparation / Reforestation / Prescribed Burning / Pesticides / Fertilization / Minor Drainage / Endangered Species Act / Additional Management Options: Wildlife Management / Glossary

Forest Management/ Reference Resources / Environmental Forestry/ Braided Stream Systems