Temporary bypass culvert, flume, or channel projects shall incorporate mitigation measures as necessary to achieve no-net-loss of productive capacity of fish and shellfish habitat. The following shall apply to temporary bypass culvert, flume, or channel projects:
(1) The temporary bypass culvert, flume, or channel shall be in place prior to initiation of other work in the wetted perimeter.
(2) A sandbag revetment or similar device shall be installed at the inlet to divert the entire flow through the culvert, flume, or channel.
(3) A sandbag revetment or similar device shall be installed at the downstream end of the culvert, flume, or channel to prevent backwater from entering the work area.
(4) The culvert, flume, or channel shall be of sufficient size to pass flows and debris for the duration of the project.
(5) For diversion of flow into a temporary channel the relevant provisions of WAC
222-110-080, channel change/realignment, shall apply.
(6) Prior to releasing the water flow to the project area, all bank protection or armoring shall be completed. See board manual section 5 for project site preparation best management practices.
(7) Upon completion of the project, all material used in the temporary bypass shall be removed from the site and the site returned to preproject conditions.
(8) The department may require fish capture and safe transport from the project site to the nearest free-flowing water if fish could be adversely impacted as a result of the project. The department of fish and wildlife may assist in capturing and safely removing fish to free-flowing water if personnel are available.
(9) Alteration or disturbance of the banks and bank vegetation shall be limited to that necessary to construct the project. All disturbed areas shall be protected from erosion within seven days of completion of the project using vegetation or other means. The banks shall be revegetated with native or other approved woody species, or stabilized with other approved erosion control techniques, and maintained as necessary to ensure survival. See board manual section 5 for technical guidance.