Washington Administrative Code › Title 222 - Forest Practices Board › Chapter 222-24 - Road construction and maintenance › Section 222-24-041 - *Water crossing structures in Type S and F Waters

Current through Register Vol. 24-14, July 15, 2024
(1) In Type Sand F Waters, bridges are
			 preferred as water crossing structures in order to ensure free and unimpeded
			 fish passage for adult and juvenile fishes and preserve spawning and rearing
			 habitat. Pier placement waterward of the ordinary high water line shall be
			 avoided where practical. Other structures which may be approved include, in
			 descending order of preference: Temporary culverts; bottomless arch culverts;
			 arch culverts; round culverts; and fords. Corrugated culverts are generally
			 preferred over smooth surfaced culverts. Culvert baffles and downstream control
			 weirs are discouraged except to correct fish passage problems at existing
			 structures.
(2) An approved forest
			 practices application is required for construction, structural work, and
			 maintenance associated with any bridge structure. Typical maintenance includes
			 painting and other activities where there is potential for wastage of paint,
			 sandblasting material, sediments, or bridge parts into the water, or where the
			 work, including equipment operation, occurs waterward of the ordinary high
			 water line.
(3) Water crossing
			 structure projects shall incorporate mitigation measures as necessary to
			 achieve no-net-loss of productive capacity of fish and shellfish
			 habitat.
(4)
Bridge
			 construction.
(a) Excavation for and
			 placement of the foundation and superstructure shall be outside the ordinary
			 high water line unless the construction site is separated from the stream by
			 use of an approved dike, cofferdam, or similar structure.
(b) The bridge structure or stringers shall
			 be placed in a manner to minimize damage to the bed.
(c) Alteration or disturbance of bank or 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 the other
			 erosion control techniques, and maintained as necessary to ensure survival. See
			 board manual section 5 for technical guidance.
(d) Removal of existing or temporary
			 structures shall be accomplished so that the structure and associated material
			 does not enter the stream.
(e) The
			 bridge shall be constructed, according to the approved design, to pass the
			 100-year flood level and debris likely to be encountered. Exception shall be
			 granted if applicant provides hydrologic or other information that supports
			 alternative design criteria.
(f)
			 Wastewater from project activities and water removed from within the work area
			 shall be routed and deposited to the forest floor in an upland area, or above
			 the 100-year flood level if present, to allow removal of fine sediment and
			 other contaminants prior to being discharged to typed waters.
(g) Structures containing concrete shall be
			 sufficiently cured prior to contact with water to avoid leaching.
(h) Abutments, piers, piling, sills, approach
			 fills, etc., shall not constrict the flow so as to cause any appreciable
			 increase (not to exceed 0.2 feet) in backwater elevation (calculated at the
			 100-year flood level) or channel wide scour and shall be aligned to cause the
			 least effect on the hydraulics of the watercourse.
(i) Riprap materials used for structure
			 protection shall be angular rock and the placement shall be installed according
			 to an approved design to withstand the 100-year flood level.
(j) Wood or other materials treated with
			 preservatives shall be sufficiently cured to minimize leaching into the water
			 or bed. The use of creosote or pentachlorophenol is not allowed.