BMP Field Manual
Chapter 7 - Timber Harvesting
Harvesting includes felling trees and transporting logs on skid trails to a landing where products are sorted and loaded onto trucks for transport to a mill. Skid trails are temporary travel-ways for logging equipment to transport felled trees or logs to a landing. They are not intended for over-the-road vehicles. Skid trails that require excavation need careful design and should follow BMPs in Forest Roads. Landings may be permanent or temporary features. If permanent, they may be used as parking areas or wildlife openings.
Follow BMPs in Planning.
For BMPs concerning skid trails and landings in wetlands, see Wetlands.
- Limit the length and number of skid trails, and the number of landings and stream crossings to the minimum necessary to conduct the harvest operation and to meet the landowner's objectives.
When harvesting near streams or lakes, follow BMPs in Riparian Management Zones.
- Whenever possible, winch logs from steep slopes if conventional skidding could cause erosion that affects water quality.
- Avoid operating equipment where excessive soil compaction and rutting may cause erosion that affects water quality. The use of low ground pressure equipment may allow operations to continue.
- Fill in ruts, apply seed and mulch, and install sediment-control structures and drainage structures on skid trails and landings where needed to prevent erosion and sedimentation into surface waters. See the Drainage Structures section and the Soil Stabilization section of Forest Roads.
- Inspect soil-stabilization practices periodically during, and immediately after, harvest operations to insure they are successful and remain functional. Follow BMPs in the Road Maintenance section of Forest Roads.
- Do not pile slash into drainage areas where runoff may wash slash into streams, lakes or wetlands.
- For winter harvesting, mark stream channels and existing culvert locations before snowfall.
- Locate landings outside riparian management zones.
- Locate landings on frozen ground or on firm well-drained soils with a slight slope, or on ground shaped to promote efficient drainage. Landings may need a crown shape to allow for drainage.
- Use existing landings if possible. Close existing landings in riparian management zones unless construction of new landings will cause greater harm to water quality than using existing landings.
- Locate residue piles (sawdust, field chipping residue, etc.) away from drainages where runoff may wash residue into streams, lakes or wetlands.
Skid trail restrictions in riparian management zones are described in Riparian Management Zones.
- Where possible, keep skid trail grades less than 15%. Where steep grades are unavoidable, break the grade, install drainage structures, and use Soil Stabilization practices (Forest Roads) where needed to minimize runoff and erosion. Grades greater than 15% should not exceed 300 feet in length.
- Use existing trails if they provide the best long-term access. Consider relocating existing trails if both access and environmental impact can be improved.
- Stream Crossings for Skidding
- Pole fords may be used in small streams by placing poles (or small logs) side by side on the streambed. Pole fords must be removed immediately after use or before the upstream end becomes clogged with debris and impedes streamflow.
- Frozen fords are used in small streams when ice is thick enough, or the streambed is frozen enough, to protect the streambed.
For skidding across streams, use permanent crossings as described in the General BMPs for Stream Crossings section of Forest Roads, or use temporary crossings such as pole fords and frozen fords.
Reminder: Stream crossing permits are required before installing a crossing on any intermittent or perennial navigable stream.
Pole ford for small stream crossings. Pole fords must be removed immediately after use or before the upstream end becomes clogged with debris and impedes streamflow. (Adapted from Vermont Department of Forests, Parks and Recreation, 1987.)
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