Current through Register Vol. 24-18, September 15, 2024
The requirements in this section apply to location, design,
and construction of permanent and seasonal docks, piers, ramps (gangways),
floats, watercraft lifts, and mooring buoys.
(1)
Description: Docks are
structures that are fixed to the shoreline but floating upon the water. Piers
are fixed, piling-supported structures. Floats (rafts) are floating structures
that are moored, anchored, or otherwise secured in the water that are not
directly connected to the shoreline. A ramp is a structure that connects a pier
or shoreline to a float and provides access between the two. Pilings usually
associated with these structures are timber, steel, reinforced concrete, or
composite posts that are driven, jacked, or cast vertically into the bed. A
watercraft lift is a structure that lifts boats and personal watercraft out of
the water. A mooring buoy is a structure floating on the surface of the water
that is used for private and commercial vessel moorage.
(2)
Fish life concerns:
(a) Over-water and in-water structures can
alter physical processes that create or maintain habitat that supports fish
life. These processes include light regime, hydrology, substrate conditions,
and water quality. However, light reduction is a main impact to fish life at
critical life stages. Light reduction, or shading, by over-water or in-water
structures reduces survival of aquatic plants. Aquatic plants provide food,
breeding areas, and protective nurseries for fish life.
(b) Shallow water provides juvenile fish a
refuge from predators like larger fish. Over-water and in-water structures can
alter movement of juvenile salmon, steelhead, and other fish species.
Structures grounding on the bed can physically block migration and cause other
impacts. The light/dark contrast of shading/no shading of over-water and
in-water structures can affect migration behavior. Fish respond by moving into
deeper water which increases the risk of predation. These structures may
increase the exposure of juvenile salmon, steelhead, and other small fish to
predators by providing predator habitat.
(3)
Residential and public recreational
dock, pier, ramp, float, watercraft lift and buoy design - General:
(a) The design and location of structures
must follow the mitigation sequence to protect freshwater habitats of special
concern.
(b) Design and locate
structures to protect fish spawning areas.
(c) Design and locate structures to protect
juvenile salmonid migration, feeding, and rearing areas where shading impacts
are a concern.
(i) Limit the width of
residential piers and docks to six feet for the first 30 feet from the
shoreline (measured from mean low water). Limit the width of recreational piers
to the minimum width needed to accommodate the intended use.
(A) In certain river systems alternative
residential pier and dock criteria may apply.
(B) For the Columbia River, limit the width
of residential piers and docks to six feet for the first 50 feet from the
shoreline. Docks must have 20 feet of water depth below them (both criteria
measured at mean low water).
(ii) Piers must extend far enough from the
shoreline so floats do not impact juvenile salmonid migration, feeding, and
rearing areas. Grounding of floats is approved in reservoirs and impoundments
only at times of the year when the water level is dropped.
(iii) The underside of pier must be at least
one and one-half feet above the OHWL elevation unless prohibited by local land
use regulations.
(iv) The
department will require residential pier, dock, ramp and float designs to
include grating. The department may require public recreational pier, dock,
ramp and float designs to include grating.
(A)
North/south oriented piers (338 to 22 degrees, or 158 to 202 degrees) greater
than four feet in width must have at least 30 percent of the entire deck
surface covered in functional grating. The grating must be installed parallel
to the length of the pier for the entire length of the pier.
(B) Northeast/southwest, northwest/southeast
and east/west oriented piers (23 to 157 degrees, 203 to 337 degrees) must have
at least 50 percent of the entire deck surface covered in functional grating
regardless of width. The grating must be installed parallel to the width of the
pier, evenly spaced along the entire length of the pier.
(C) In water bodies with a high density of
piers and docks, the department may require that grating cover entire deck
surface of the pier or dock.
(D)
Limit the width of residential ramps to four feet wide. Limit the width of
public recreational ramps to the minimum width needed to accommodate the
intended use. Cover the entire ramp surface with grating.
(E) A dock or float six feet wide or narrower
must have at least 30 percent of the deck surface covered in functional
grating. A dock or float wider than six feet (up to eight feet wide) must have
at least 50 percent of the deck surface covered in functional grating. The
grating material's open area must be at least 60 percent. In some water bodies
the department may require a higher proportion of grating. Locate flotation
under the solid decked area only. Orient grating so the lengthwise opening
maximizes the amount of light penetration. Any objects that are not part of the
structure on, above, or below the grating should not block light
penetration.
(F) If only the
minimum deck surface area described in (c)(iv) of this subsection is grated,
the grating material's open area must be at least 60 percent unless the grating
covers more than the minimum deck area. If the grating covers more than the
minimum deck surface area, the grating material's open area can be reduced to
at least 40 percent open area.
(d) If artificial nighttime lighting is used
in the design, use low-intensity lights that are located and shielded to
prevent light from attracting fish, unless there are safety
constraints.
(e) Flotation for the
structure must be fully enclosed and contained in a shell. Flotation containing
expanded or extruded plastic foam must be enclosed in a shell made of plastic
with a minimum thickness of 0.15 inches, concrete, aluminum, or steel. The
shell must prevent breakup or loss of the flotation material into the water.
The shell must not be readily subject to damage by ultraviolet radiation and
abrasion.
(f) The design must not
include skirting including batter fencing constructed around piers, docks, or
floats unless approved by the department.
(g) Embedded anchor(s) or other approved
anchor(s) or piling may hold floats in place.
(h) The design should not use treated wood
for the decking of the structure. The design may use treated wood for
structural elements. Treated wood structural elements subject to abrasion by
vessels, floats, or other objects must incorporate design features to minimize
abrasion of the wood.
(i) The
structure must have been usable at the site within the 12 months immediately
before the time of application submittal to be considered a replacement
structure. Usable means no major deterioration or section loss in critical
structural components is present.
(j) Replacement of more than 33 percent or
250 square feet of decking or replacement of decking substructure requires
installation of functional grating in the replaced portion only. The grating
must conform to the requirements in this section.
(4)
Piling design:
(a) Use the smallest diameter and number of
pilings required to construct a safe structure.
(b) Steel piling used to construct
residential docks should not exceed six inches in diameter. Limit the diameter
of steel piling used to construct public recreational docks to the minimum
width needed to accommodate the intended use.
(c) The use of creosote or pentachlorophenol
piling is prohibited. New and replacement piling can be steel, concrete,
recycled plastic, and/or untreated or department-approved treated
wood.
(d) Treated wood piling must
incorporate design features to minimize abrasion of the piling from contact
with vessels, floats, or other objects.
(e) All pilings must be fitted with devices
to prevent perching by fish-eating birds.
(5)
Watercraft lift design:
(a) The design of the watercraft lift/grid
must follow the mitigation sequence to protect juvenile salmonid migration,
feeding, and rearing areas where shading impacts are a concern.
(b) The bottom of the watercraft lift/grid
must be at least one foot above the bed.
(c) Use the minimum number of pilings needed
to support the watercraft lift/grid.
(6)
Mooring buoy design:
(a) In water bodies where mooring buoy
systems might damage the bed and native submerged aquatic vegetation, locate
and design the buoy system to minimize damage.
(i) Locate the buoy deep enough to prevent
vessel grounding.
(ii) Design and
install the buoy system with mid-water floats so that anchor lines do not
drag.
(iii) In areas with native
submerged aquatic vegetation, use an embedment-style mooring anchor instead of
a surface-style mooring anchor.
(iv) Adequately size the mooring to prevent
the anchor from shifting or dragging along the bed.
(b) If the department authorizes the use of a
concrete anchor, use a precast concrete anchor.
(c) The mooring buoy must have a shell that
is not readily subject to damage by ultraviolet radiation and abrasion caused
by rubbing against vessels, the bed, and/or waterborne debris.
(7)
Residential and public
recreational docks, pier, ramp, float, watercraft lift, and buoy
construction:
(a) Operate and anchor
vessels and barges during construction in a manner that protects native aquatic
vegetation.
(b) Reestablish the
pier or dock centerline during the construction phase using the same
methodology used to establish the centerline on the construction
drawings.
(c) When installing steel
piling, a vibratory hammer or water jet to drive piling is preferred.
(d) If impact pile driving is needed, set the
drop height to the minimum needed to drive the piling.
(e) Use appropriate sound attenuation to
minimize harm to fish from impact pile-driving noise.
(f) To avoid attracting fish to lights at
night, limit impact pile driving to daylight hours whenever feasible.
(g) The department may require the following
when removing piling:
(i) Use a vibratory or
water jet system to dislodge piling whenever feasible.
(ii) After removal, place the piling on a
construction barge or other dry storage site. Piling removed from the substrate
must be moved immediately from the water into a barge or other dry storage
site. The piling must not be shaken, hosed off, left hanging to dry or any
other action intended to clean or remove adhering material from the
piling.
(iii) If a treated wood
piling breaks during extraction, remove the stump from the water column by
fully extracting the stump or cut it three feet below the substrate and cap all
buried stumps with clean sediment that matches the native material.
(iv) Fill holes left by piling extraction
with clean sediment that matches the native material whenever
feasible.
(h) Securely
anchor docks, floats, and mooring buoys.
(i) If the department authorizes the use of a
concrete anchor, use a precast concrete anchor.
(j) Dispose of removed docks, piers, ramps,
floats, lines, chains, cables, and mooring anchors in an upland disposal
site.
(k) Place floats and buoys
removed seasonally in an upland area. Do not store on the beach.