Dredging projects shall incorporate mitigation measures as necessary to achieve no-net-loss of productive capacity of fish and shellfish habitat. The following technical provisions apply to dredging projects. In addition, these projects shall comply with technical provisions and timing restrictions in WAC 220-110-240
(1) In addition to those timing limitations listed in WAC 220-110-271
, dredge timing may be further restricted to protect other important fish life.
(2) If a fish kill occurs or fish are observed in distress, dredging shall immediately cease and the department shall be notified immediately.
(3) A hydraulic dredge shall only be operated with the intake at or below the surface of the material being removed. The intake shall only be raised a maximum of three feet above the bed for brief periods of purging or flushing the intake system.
(4) Each pass of a clamshell dredge bucket shall be complete. Stockpiling of dredged material below the ordinary high water line may be prohibited.
(5) Dredging shall be conducted with dredge types and methods that cause the least adverse impact to fish and shellfish and their habitat.
(6) Dredged bed materials shall be disposed of at approved in-water disposal sites or upland. The department may allow placement of dredged material in areas for beneficial uses such as beach nourishment or cleanup of contaminated sediments.
(7) Dredging shall be conducted to a depth not greater than the channel depth at the seaward end. Dredging to depths greater than the channel at the seaward end may be authorized only in berthing areas and turning basins for commercial shipping purposes.
(8) Dredging is prohibited in herring spawning beds and in rockfish and lingcod settlement and nursery areas.
(9) Kelp (Order laminariales) adversely impacted due to dredging shall be replaced using proven methodology.
(10) Dredging shall avoid adverse impacts to eelgrass (Zostera spp).
[Statutory Authority: RCW 75.08.080
. WSR 94-23-058 (Order 94-160), § 220-110-320, filed 11/14/94, effective 12/15/94; WSR 87-15-086 (Order 87-48), § 220-110-320, filed 7/20/87. Statutory Authority: RCW 75.20.100
and 75.08.080. WSR 83-09-019 (Order 83-25), § 220-110-320, filed 4/13/83.]