Current through Register Vol. 24-18, September 15, 2024
Appropriate methods to assess the need for marine shoreline
stabilization and, if needed, to design marine shoreline stabilization are
available in the department's Marine Shoreline Design
Guidelines, as well as other published manuals and guidelines.
(1)
Description: A broad
spectrum of shoreline stabilization techniques can be applied to protect
property. These range from passive techniques that require minimal or no
engineering, engineered soft shore protection, and hard shoreline armor.
Passive techniques include planting native vegetation, improving drainage, and
relocating buildings, roads, and improvements (e.g., wells, utilities, septic
fields, and the like). Passive techniques typically preserve the natural
condition of the shore and have few to no negative impacts on fish life. Soft
shore techniques such as log placement, beach nourishment, resloping the bank,
and re-vegetation can provide erosion protection using strategically placed
natural materials while reducing impacts to beach processes and fish habitat.
Conventional hard techniques include bulkheads, seawalls, revetments and
related structures, which are designed to preclude shoreline migration and bank
erosion. Each type of approach has varying degrees of impact. In general,
passive techniques result in the fewest impacts to fish life and hard
techniques have the most impacts.
(2)
Fish life concerns:
Conventional hard techniques as well as some soft shore techniques can
physically alter the beach and disrupt beach processes. Sea level rise will
magnify the loss of beach habitat if beaches are unable to retreat due to the
presence of shoreline stabilization. This alteration can cause a loss of the
beach spawning habitat for Pacific sand lance and surf smelt. These forage fish
species are a primary food source for some adult salmon species. This
alteration can also reduce beach complexity, the presence of marine riparian
vegetation including overhanging vegetation alongshore that produces
terrestrial insects that are eaten by juvenile salmon, and this may be
exacerbated by the effects of climate change. To protect fish life, the
department protects both beaches where saltwater habitats of special concern
occur and the beach processes that form and maintain this habitat.
(3)
Alternative selection:
(a) To ensure the protection of fish life, a
person must use the least impacting technically feasible shoreline
stabilization alternative. For the purpose of this section, "feasible" means
available and capable of being done after taking into consideration cost,
existing technology, and logistics in light of overall project purposes. A
person should propose a hard armor technique only after considering site
characteristics such as the threat to major improvements, wave energy, and
other factors in an alternatives analysis.
(b) Common alternatives for both new
shoreline stabilization and the replacement or rehabilitation of shoreline
stabilization that extends waterward of an existing shoreline stabilization
structure are, from most preferred to least preferred:
(i) Remove any existing shoreline
stabilization structure and restore the beach;
(ii) Control upland drainage;
(iii) Protect, enhance, and replace native
vegetation;
(iv) Relocate buildings
and improvements;
(v) Construct a
soft structure;
(vi) Construct
upland retaining walls;
(vii)
Construct a hard structure landward of the ordinary high water line;
and
(viii) Construct a hard
structure at the ordinary high water line.
(c) Common alternatives for replacement or
rehabilitation of residential shoreline stabilization are, from most preferred
to least preferred:
(i) Remove the existing
shoreline stabilization structure and restore the beach;
(ii) Remove the existing shoreline
stabilization structure and install native vegetation;
(iii) Remove the existing shoreline
stabilization structure and control upland drainage;
(iv) Remove the existing shoreline
stabilization structure and replace it with a soft structure constructed of
natural materials, including bioengineering;
(v) Remove the existing hard structure and
construct upland retaining walls;
(vi) Remove the existing hard structure and
replace it landward with another hard structure, preferably at or above the
ordinary high water line; or
(vii)
Remove the existing hard structure and replace it in the same footprint with
another hard structure.
(d) Except as provided in (f) of this
subsection, HPA applications for the following types of projects must include a
site assessment, alternatives analysis and design rationale for the proposed
method(s) prepared by a qualified professional (Qualified Professional's
Report):
(i) New shoreline
stabilization;
(ii) Replacement or
rehabilitation of shoreline stabilization that extends waterward of an existing
shoreline stabilization structure; and
(iii) Replacement or rehabilitation of
residential shoreline stabilization.
(e) The applicant must submit the Qualified
Professional's Report to the department as part of a complete application for
an HPA that includes:
(i) An assessment of the
level of risk to existing buildings, roads, or services being threatened by the
erosion;
(ii) Evidence of erosion
and/or slope instability to warrant the stabilization work;
(iii) Alternatives considered and the
technical rationale specific to the shoreline stabilization technique
proposed;
(iv) An analysis of the
benefits and impacts associated with the chosen protection method;
and
(v) An explanation of the
method chosen, design parameters, types of materials, quantities, staging, and
site rehabilitation.
(f)
The department may grant an exemption to the Qualified Professional's Report
required under (d) and (e) of this subsection based on the scale and nature of
the project for the following:
(i) Projects
for the removal of an existing shoreline stabilization structure and
restoration of the beach.
(ii)
Projects employing passive techniques such as controlling upland drainage or
planting native vegetation.
(iii)
Other projects as assessed by the department.
(g) Emergency or expedited applications
submitted under
RCW
77.55.021(12), (14), or (16)
that do not include a site assessment and alternatives analysis report should
identify only the work necessary to stabilize the emergency or expedited
conditions authorized under
RCW
77.55.021. A site assessment and alternatives
analysis report must be submitted within 90 days from the permit issuance
unless the department issues an exemption. After consideration of the
assessment and analysis report, if the department determines that shoreline
stabilization work conducted under the emergency or expedited permit is not the
least impactful technically feasible alternative, the applicant may be required
to replace the structure with one that is the least impactful technically
feasible alternative.
(4)
Shoreline stabilization
design:
(a) If the ordinary high water
line (OHWL) has changed since an existing hard shoreline stabilization
structure was built, and OHWL reestablishes landward of the structure, the
department will consider this reestablished OHWL to be the existing OHWL for
permitting purposes. If an HPA application is submitted for repairs within
three years of the breach, the prior OHWL may be considered for permitting
purposes.
(b) The construction of
all shoreline stabilization must not result in a permanent loss of surf smelt
or Pacific sand lance spawning beds.
(c) The department may require the design of
hard shoreline stabilization structures to incorporate beach nourishment, large
woody material or native vegetation as mitigation.
(5)
Shoreline stabilization
location:
(a) Locate the waterward face
of a new hard shoreline stabilization structure at or above the OHWL. Where
this is not feasible because of geological, engineering, or safety concerns,
the hard structure may extend waterward of the OHWL the least distance needed
to excavate for footings or place base rock, but no greater than six feet. Soft
shoreline methods that allow beach processes and habitat to remain intact may
extend waterward of the OHWL.
(b)
Do not locate the waterward face of a replacement or repaired hard shoreline
stabilization further waterward than the structure it is replacing. Where
removing the existing hard structure will result in environmental degradation
such as releasing deleterious material or problems due to geological,
engineering, or safety concerns, the department will authorize the replacement
shoreline stabilization to extend water-ward of, but directly abutting, the
existing structure. In these instances, a person must use the least-impacting
type of structure and construction method.
(6)
Shoreline stabilization
construction:
(a) The department
requires that plans submitted as part of a complete application show the
horizontal distances of the structure(s) from permanent local benchmark(s)
(fixed objects). Each horizontal distance shown must include the length and
compass bearing from the benchmark to the waterward face of the structure(s).
The benchmark(s) must be located, marked, and protected to serve as a
post-project reference for at least 10 years from the date the HPA application
is submitted to the department.
(b)
A person must not conduct project activities when tidal waters cover the work
area including the work corridor, except the area occupied by a grounded
barge.
(c) No stockpiling of
excavated materials containing silt, clay, or fine-grained soil is approved
waterward of the OHWL.
(d) The
department may allow stockpiling of sand, gravel, and other coarse material
waterward of the OHWL. Place this material within the designated work corridor.
Remove all excavated or stockpiled material from the beach within 72 hours of
construction.
(e) Backfill all
trenches, depressions, or holes created during construction that are waterward
of the OHWL before they are filled by tidal waters.
