Large woody material removal or repositioning projects shall incorporate mitigation measures as necessary to achieve no-net-loss of productive capacity of fish and shellfish habitat. The following technical provisions shall apply to large woody material removal or repositioning:
(1) Large woody material removal from watercourses shall only be approved where necessary to address safety considerations, or its removal would not diminish the fish habitat quality of the watercourse. The department may approve the repositioning of large woody material within the watercourse to protect life and property or as needed to conduct a hydraulic project. Repositioned large woody material shall be placed or anchored to provide stable, functional fish habitat.
(2) Large woody material removal shall be conducted by equipment stationed on the bank, bridge, or other approved structure.
(3) Unless otherwise authorized, large woody material shall be suspended during its removal so no portion of the large woody material or limbs can damage the bed or banks. Yarding corridors or full suspension shall be required to avoid damage to riparian vegetation. It may be necessary to cut the large woody material in place, to a size that allows suspension during removal.
(4) Where large woody material cannot be suspended above the bed and banks, skid logs or similar methods shall be used to avoid bank damage. Upon completion of the yarding operation, skid logs shall be removed in a manner that avoids damage to streambanks and vegetation, and the bank shall be restored to preproject condition.
(5) Smaller limb and bark debris associated with the large woody material shall be removed and disposed of so as not to reenter the watercourse.
(6) Large woody material embedded in a bank or bed shall be left undisturbed and intact except where authorized for removal.
(7) Large woody material removal or repositioning shall be accomplished in a manner which minimizes the release of bedload, logs, or debris downstream.
(8) Depressions created in gravel bars shall be filled, smoothed over, and sloped upwards toward the bank on a minimum two percent gradient.
[Statutory Authority: RCW 75.08.080
. WSR 94-23-058 (Order 94-160), § 220-110-150, filed 11/14/94, effective 12/15/94. Statutory Authority: RCW 75.20.100
and 75.08.080. WSR 83-09-019 (Order 83-25), § 220-110-150, filed 4/13/83.]