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Contact

UI Extension Forestry

Mailing Address:

875 Perimeter Drive MS 1140
Moscow, ID 83844-1140

Phone: 208-885-7718

Email: yvonnec@uidaho.edu

Google Maps

University of Idaho Extension, Kootenai County

Mailing Address:
1808 N 3rd St
Coeur d’Alene, ID 83814-3407

Phone: (208) 446-1680

Fax: (208) 446-1690

Email: kootenai@uidaho.edu

Web: UI Extension, Kootenai County

Chris Schnepf Google Maps

UI Extension, Clearwater County

Mailing Address:

2200 Michigan Avenue
Orofino, ID 83544

Phone: 208-476-4434

Email: williamw@uidaho.edu

Build a slash filter windrow

Slash filter windrows are structures made out of waste logs and compacted slash. They protect forest streams from sediment originating on road surfaces and fill slopes, stabilize road fills and help prevent stream sedimentation during road construction. Windrows can be constructed on both sides of a road or just on one side, depending on the type of road and surrounding topography.

Slash filter windrows should not substitute for right-of-way slash disposal; normally only a small part of right-of-way debris and slash is used in windrows.

How to build the windrow

  1. As you clear the right-of-way, stockpile tree tops, limbs, brush not exceeding 6 inches in diameter and cull logs at least 18 inches in diameter. Cull logs should be approximately 12 feet long; they will be used as anchors.
  2. Stockpile material either above or below the clearing limits. Piles should be at locations that provide the best access for constructing the windrows after road grade excavation and shaping is completed.
  3. Windrow length should extend no more than 300 to 400 feet each way from a stream crossing unless the road parallels the stream. If the windrow extends more than 400 feet, it is advisable to leave wildlife corridors every 200 feet.
  4. After fill construction is completed, construct the windrow using an excavator. Start by placing anchor logs just at or below the toe of the fill. Anchor these logs against stumps, rocks or trees parallel to the fill toe line.
  5. Continue to use the excavator to pack slash by tamping above and along the length of the anchor logs. Embed the slash in the fill slope in quantities sufficient to make a sediment-impervious windrow 2 to 3 feet high and 6 to 10 feet wide.
slash filter windrow diagram top view slash filter windrow diagram side view
(Illustrations by Noah Kroese)

For more information, see IDL Forester Forum Forest Practices No. 13 — Slash Filter Windrows.

Contact

UI Extension Forestry

Mailing Address:

875 Perimeter Drive MS 1140
Moscow, ID 83844-1140

Phone: 208-885-7718

Email: yvonnec@uidaho.edu

Google Maps

University of Idaho Extension, Kootenai County

Mailing Address:
1808 N 3rd St
Coeur d’Alene, ID 83814-3407

Phone: (208) 446-1680

Fax: (208) 446-1690

Email: kootenai@uidaho.edu

Web: UI Extension, Kootenai County

Chris Schnepf Google Maps

UI Extension, Clearwater County

Mailing Address:

2200 Michigan Avenue
Orofino, ID 83544

Phone: 208-476-4434

Email: williamw@uidaho.edu