Current through Register Vol. 24-18, September 15, 2024
This section applies to the design and construction of
permanent, seasonal or temporary docks, piers, ramps (gangways), floats,
watercraft lifts, and mooring.
(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 gangway 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 or jacked into
the bed. A watercraft lift is a structure that lifts boats and personal
water-craft 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. Light reduction is the 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 damage forage fish
spawning beds. The light/dark contrast of shading/no shading caused by
over-water and in-water structures can affect migration behavior. Fish respond
by moving into deeper water which increases the risk of predation.
(3)
Residential and public
recreational pier, ramp, float, water-craft lift and buoy design -
Generally:
(a) The department requires
that new structures are designed with a pier and ramp to span the intertidal
beach, whenever feasible.
(b) The
design and location of structures must follow the mitigation sequence to
protect salt water habitats of special concern.
(i) Design and locate structures to protect
juvenile salmonid migration, feeding, and rearing areas.
(ii) Design and locate structures to protect
documented Pacific herring, Pacific sand lance, and surf smelt spawning beds;
and rock-fish and lingcod settlement and nursery areas.
(iii) The department will require a
seagrass/macroalgae habitat survey for all new construction unless the
department can determine the project will not impact seagrass and kelp beds,
and in herring spawning beds other macroalgae used as spawning substrate. A
survey is not required for replacement of an existing structure within its
original footprint.
(A) Structures must be
located at least 25 feet (measured horizontally from the nearest edge of the
structure) and four vertical feet away from seagrass and kelp beds (measured at
extreme low water).
(B) In
documented herring spawning areas, structures must be located at least 25 feet
(measured horizontally from the nearest edge of the structure) and four
vertical feet from macroalgae beds on which herring spawn (measured at extreme
low water).
(iv) If
artificial nighttime lighting is used in the project, use low-intensity lights
that are located and shielded to prevent light from attracting fish or
disrupting fish migration behavior, unless there are safety
constraints.
(v) The design must
not include skirting including batter fencing constructed around piers, docks,
or floats unless approved by the department. 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 such as rub
strips to minimize abrasion of the wood.
(c) The structure must have been usable at
the site within the past 12 months of 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.
(d) 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 section only. The grating
must conform to the requirements in this section.
(4)
Pier and ramp design:
(a) Design piers to maximize height over the
bed to improve light transmission. The bottom of the pier must be at least six
feet above the bed at the landward end.
(b) Limit the width of residential piers to
no more than six feet wide. Limit the width of recreational piers to the
minimum width needed to accommodate the intended use.
(c) 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.
(d)
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.
(e) If
only the minimum pier deck surface described in (c) or (d) of this subsection
is covered, the grating material's open area must be at least 60 percent open
area unless grating covers more than the minimum pier deck area of the pier. If
the grating covers more than the minimum deck surface area, the grating
material's open area can be reduced down to at least 40 percent open
area.
(f) 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.
(5)
Float design (floats connected to a
pier):
(a) Whenever feasible, place
float so that the largest dimension is oriented north/south.
(b) Limit the width of residential floats to
eight feet. Limit the width of public recreational floats to the minimum width
needed to accommodate the intended use.
(c) Whenever feasible, limit the length of
single-family dock floats to 30 feet and joint-use dock floats to 60
feet.
(d) If the design has a float
positioned perpendicular to the ramp to serve as a ramp landing, this float
must not be more than six feet wide and 10 feet long.
(e) Design floats in intertidal areas with
stoppers or support pilings that keep the bottom of the floats at least one
foot above the substrate so that the structure will not rest on the
bottom.
(f) A float six feet wide
or less must have at least 30 percent of the entire deck surface covered in
functional grating. A float between six and eight feet wide must have at least
50 percent of the entire deck surface covered in functional grating. 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. Flotation must be located under the solid
decked area only.
(g) The grating
material's open area must be at least 60 percent.
(h) 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.
(i) Embedded anchor(s), pilings (with stops),
and float support/stub pilings may be used to hold floats in place.
(j) If a project uses anchors to hold the
float in place, the anchor lines must not rest on the substrate at any
time.
(6)
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 12 inches in diameter. Limit the diameter
of steel piling used to construct public recreational docks to the minimum
diameter 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, or untreated or treated wood approved by the
department.
(d) Treated wood piling
must incorporate design features to minimize abrasion of the piling from
contact with vessels, floats, or other objects.
(e) Fit all pilings with devices to prevent
perching by fish-eating birds.
(7)
Watercraft lift/grid design:
(a) Design the watercraft lift/grid to
minimize shading caused by the structure.
(b) The bottom of the watercraft lift/grid
must be at least one foot above the bed.
(c) Use the minimum number of piling needed
to support the water-craft lift/grid.
(8)
Buoy design: In water bodies
where buoy systems might damage submerged aquatic vegetation, locate and design
the buoy system to minimize damage.
(a)
Whenever feasible, use an embedded anchor.
(i)
A seagrass/macroalgae habitat survey is not required if an embedment-style
mooring anchor is installed. The department will require the diver/installer to
locate the anchor so the mooring buoy system will not damage seagrass and kelp
beds, and in herring spawning beds other macroalgae used as spawning
substrate.
(ii) A
seagrass/macroalgae habitat survey is required if a surface style mooring
anchor is installed. The survey is needed to ensure the mooring buoy system is
installed at a location where sea-grass, kelp, and in herring spawning beds
other macroalgae used as spawning substrate will not be damaged.
(b) Place the buoy deep enough to
prevent vessel grounding.
(c)
Locate the buoy to avoid damage from vessel propellers to submerged aquatic
vegetation.
(d) Design the buoy
system with a mid-water float so that anchor lines do not drag.
(e) Adequately size the mooring to prevent
the anchor from shifting or dragging along the bed.
(f) If the department authorizes the use of a
concrete anchor, use a precast concrete anchor.
(g) The buoy must have a shell that is
resistant to ultraviolet radiation (sunlight) and abrasion caused by rubbing
against vessels, the bed, and/or waterborne debris.
(9)
Replacement floating docks:
The department will authorize replacement floating docks, if:
(a) The area of replaced floating dock
structure is not expanded;
(b) The
replaced floating dock is not relocated within waters of the state without
written authorization from the department. The replaced structure must be
removed and disposed of upland so it will not reenter state waters;
(c) Floats are designed with stoppers or
support pilings that keep the bottom of the floats at least one foot above the
substrate so that the structure will not rest on the bottom;
(d) A float six feet wide or less must have
at least 30 percent of the entire deck surface covered in functional grating. A
float between six and eight feet wide must have at least 50 percent of the
entire deck surface covered in functional grating. 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. Flotation must be located under the solid decked area
only;
(e) The grating material's
open area must be at least 60 percent;
(f) 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.
(10)
Residential and public
recreational dock, pier, ramp, float, floating dock, watercraft lift, and buoy
construction:
(a) The dock or pier
centerline must be reestablished during construction using the same methodology
used to establish the centerline during the seagrass/macroalgae habitat
survey.
(b) When installing steel
piling, a vibratory hammer is preferred.
(c) If impact pile driving is used, set the
drop height to the minimum needed to drive the piling.
(d) Use appropriate sound attenuation to
minimize harm to fish from impact pile-driving noise.
(e) To avoid attracting fish to light at
night, limit impact pile driving to daylight hours whenever feasible.
(f) The department may require the following
during piling removal:
(i) Use of a vibratory
system to dislodge piling whenever feasible;
(ii) Place the piling on a construction barge
or other dry storage site after the piling is removed. 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 cutting 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;
(v) When removing
creosote piling:
(A) Containment booms and
absorbent booms (or other oil absorbent fabric) must be placed around the
perimeter of the work area to capture wood debris, oil, and other materials
released into marine waters as a result of construction activities to remove
creosote pilings. All accumulated debris must be collected and disposed upland
at an approved disposal site; and
(B) Creosote logs and timbers must be fully
suspended during removal so no portion of the log drags through the water or
onto the beach.
(g) Securely anchor dock, floats, and mooring
buoys.
(h) Dispose of replaced
piers, ramps, floats, docks, lines, chains, cables, or mooring anchors in an
upland disposal site; and
(i) Place
floats and buoys removed seasonally in an upland area. Do not store on the
beach.