All pier, dock, float, and piling construction 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 freshwater dock, pier, and float construction projects and the driving or removal of piling:
(1) Excavation for and placement of the footings and foundation shall be landward of the ordinary high water line unless the construction site is separated from state waters by use of an approved dike, cofferdam, or similar structure.
(2) Alteration or disturbance of the bank 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 within one year with native or other approved woody species. Vegetative cuttings shall be planted at a maximum interval of three feet (on center), and maintained as necessary for three years to ensure eighty percent survival. Where proposed, planting densities and maintenance requirements for rooted stock will be determined on a site-specific basis. The requirement to plant woody vegetation may be waived for areas where the potential for natural revegetation is adequate, or where other engineering or safety factors preclude them.
(3) Removal of existing or temporary structures shall be accomplished so that the structure and associated material does not reenter the watercourse.
(4) All piling, lumber, or other materials treated with preservatives shall be sufficiently cured to minimize leaching into the water or bed. The use of wood treated with creosote or pentachlorophenol is not allowed in lakes.
(5) Skirting or other structures shall not be constructed around piers, docks, or floats unless specifically approved in the HPA.
(6) Floatation for the structure shall be enclosed and contained, when necessary, to prevent the breakup or loss of the floatation material into the water.
(7) All work operations shall be conducted in such a manner that causes little or no siltation to adjacent areas. If at any time, fish are observed in distress, a fish kill occurs, or water quality problems develop as a result of a pier, dock, float, or piling project, construction operations shall cease and the permittee or authorized agent shall immediately contact the department.
(8) Removal of aquatic vegetation shall be limited to that necessary to gain access to construct the project.
[Statutory Authority: RCW 75.08.080
. WSR 94-23-058 (Order 94-160), § 220-110-060, filed 11/14/94, effective 12/15/94; WSR 87-15-086 (Order 87-48), § 220-110-060, filed 7/20/87. Statutory Authority: RCW 75.20.100
and 75.08.080. WSR 83-09-019 (Order 83-25), § 220-110-060, filed 4/13/83.]