Chapter 21.76
SHORELINE MODIFICATIONS
Sections:
21.76.010 General provisions applicable to shoreline modifications.
21.76.020 Overwater structures – General requirements.
21.76.030 Design and dimensional standards for piers, docks, floats, and moorage pilings.
21.76.040 Shoreline stabilization – General provisions.
21.76.050 Structural shoreline stabilization – Limitations.
21.76.060 Structural shoreline stabilization – New or enlargement.
21.76.070 Repair or replacement of structural shoreline stabilization.
21.76.080 Structural shoreline stabilization – Design consideration.
21.76.090 Shoreline stabilization – Report and application requirements.
21.76.100 Breakwaters, jetties, groins, and weirs.
21.76.110 Shoreline flood hazard reduction.
21.76.130 Dredging and disposal.
21.76.010 General provisions applicable to shoreline modifications.
The following apply to all shoreline modifications expressed under this chapter:
(1) The shoreline modification must support a permitted shoreline use or be for shoreline mitigation and/or shoreline enhancement;
(2) The shoreline modification must comply with the policies and regulations of the specific shoreline environment designation and the general shoreline regulations found in Chapter 21.73 WMC; and
(3) The shoreline modification must be constructed and maintained in a safe and sound condition and any structures determined to be unsafe or abandoned shall be removed, repaired, or have the unsafe conditions remedied immediately by the property owner. (Ord. 716 § 4 (Att. A), 2021)
21.76.020 Overwater structures – General requirements.
The following apply to all overwater structures including piers, docks, moorage piles, floats, and similar types of structures:
(1) Except for overwater structures owned by a public agency, docks, floats, and moorage pilings are prohibited within the Little Bear Creek shoreline corridor;
(2) Where allowed, overwater structures must support a permitted shoreline use;
(3) New piers and docks are allowed only for water-dependent uses or public access – as used here, a dock associated with a single-family residence is a water-dependent use provided it is designed and intended as a facility for access to watercraft and otherwise complies with the shoreline master program;
(4) Overwater structures shall be designed and constructed consistent with mitigation sequencing set forth in WMC 21.73.020(6) to minimize impacts to shoreline ecological functions and fish and wildlife habitat;
(5) Where a new development meets any one of the following conditions, joint-use dock facilities are required rather than individual ownership use:
(a) Divisions of land into two or more lots where waterfront access is provided to the new lots; or
(b) Development of two or more dwellings where waterfront access is provided to the new dwellings; and
(6) Applications for overwater structures shall include the following information:
(a) Description of the proposed structure, including size, location, design, and any other shoreline modification associated with the project;
(b) Ownership of adjacent shorelands;
(c) Proposed location of overwater structures in relationship to property lines and the ordinary high water mark;
(d) Location and general footprint of docks within 300 feet of the proposed structure; and
(e) Mitigation sequencing analysis pursuant to WMC 21.73.020. (Ord. 716 § 4 (Att. A), 2021)
21.76.030 Design and dimensional standards for piers, docks, floats, and moorage pilings.
(1) Table 21.76.030 sets forth design and dimensional standards that apply to piers, docks, moorage piles, and floats.
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Design and Dimensional Standard |
Requirements |
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|---|---|---|
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Maximum overwater coverage |
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Single property owner |
320 square feet |
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Shared/joint use |
480 square feet |
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Public |
Minimum necessary to support the public use1 |
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Maximum length |
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Farthest extension points of all structures from the ordinary high water mark |
8 feet |
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Maximum length of any structure (measured parallel to the shoreline) |
Single property owner |
40 feet |
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Shared/joint use |
60 feet |
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Public |
Minimum necessary to support the public use1 |
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Placement |
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Minimum setback from property lines (as extended in a straight line waterward) |
5 feet |
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Minimum setback for shared/joint use where straddling a common property line |
None |
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Minimum distance between piers and docks having private ownership |
100 feet |
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Maximum water frontage that can be occupied by piers, docks, and floats |
50 percent of the linear length of the waterfront lot, tract, or parcel |
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Minimum water frontage |
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Piers, docks, and floats |
Single ownership/shared joint use |
At least one lot, tract or parcel must have 50 feet of water frontage |
|
Public |
None |
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Height |
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Minimum height above the plane of the ordinary high water line and the bottom of the stringers on a pier |
1 1/2 feet |
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Maximum height above the plane of the ordinary high water line and the top of the decking of a pier |
5 feet |
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Maximum height above the surface of the water to the top of the decking of floats and docks |
2 feet |
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Maximum height of safety railing above surface decking2 |
42 inches |
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Walls, sheathing, lockers (except horizontal lockers not exceeding 42 inches above the deck in height) and similar construction not listed |
Prohibited |
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Pier skirting |
Prohibited |
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Materials |
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Decking for piers, docks, and floats |
Grating or other materials that allow a minimum 40 percent light to transmit through |
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Treatment with pentachlorophenol, creosote, chromate copper arsenate, or similar toxic compounds |
Prohibited |
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Other construction materials |
Shiny metallic surfaces are prohibited where visible to the public from land or water |
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Styrofoam floats are prohibited |
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Materials should be consistent with the natural appearance of the shoreline |
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Lighting |
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Lighting (see WMC 21.74.070) |
Minimum necessary for safety |
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Lighting shall be focused downward, but shall not shine directly onto the water |
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Limited to a color spectrum that does not give salmonids predators an advantage |
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Notes:
1 A written mitigation sequencing analysis is required pursuant to WMC 21.73.020.
2 Safety railing shall be designed to providing maximum opening to allow air and light to pass through.
(2) All overwater structures shall not impede the public use of the waterway or significantly interfere with use of navigable waters.
(3) Abandoned or overwater structures determined unsafe by the City shall be removed or repaired promptly.
(4) Where a new pier, dock, float, or moorage piling is established, a written mitigation sequencing analysis is required pursuant to WMC 21.73.020. At a minimum mitigation must include the following:
(a) Plant emergent vegetation waterward of the ordinary high water line per Washington State Fish and Wildlife and/or Corps of Engineers requirements, unless it can be demonstrated that planting is not feasible or appropriate due to environmental constraints; and
(b) Install a riparian vegetative planting adjacent to the shoreline that results in a no net loss of shoreline ecological functions standards to mitigate for impacts from the overwater structure. (Ord. 716 § 4 (Att. A), 2021)
21.76.040 Shoreline stabilization – General provisions.
Shoreline stabilization measures are used to address erosion impacts to property caused by natural processes such as water currents, floods, tides, wind, and/or wave actions. They can vary from nonstructural measures to structural measures and from soft measures to hard measures. Generally, the harder the construction measure, the greater the impact on shoreline processes, including sediment transport, geomorphology, and biological functions. The following requirements apply to all shoreline stabilization measures:
(1) New development should be located and designed to the extent feasible to avoid future needs for shoreline stabilization measures;
(2) Division of land must not create lots that will require shoreline stabilization for reasonable development to occur;
(3) New development shall be prohibited where shoreline stabilization measures will cause significant impacts to adjacent or down-current properties and shoreline areas;
(4) Shoreline stabilization shall not:
(a) Significantly interfere with normal surface and/or subsurface drainage; and
(b) Cause a hazard to navigation; and
(c) Be for the purposes of creating land;
(5) Publicly financed or subsidized shoreline stabilization shall not restrict appropriate public access to the shoreline except where such access is determined to be infeasible because of incompatible uses, safety, security, or harm to shoreline ecological functions;
(6) Where feasible, publicly financed, or subsidized shoreline stabilization shall incorporate ecological restoration and public access improvements into the project;
(7) All shoreline stabilization measures shall provide mitigation as necessary to ensure no net loss of shoreline ecological functions pursuant to the analysis in WMC 21.73.020;
(8) Structural shoreline stabilization measures shall be limited to the minimum necessary; and
(9) The U.S. Army Corps of Engineers is responsible for bank armoring and maintenance along the Sammamish River. (Ord. 716 § 4 (Att. A), 2021)
21.76.050 Structural shoreline stabilization – Limitations.
(1) For hard structural shoreline stabilization measures a geotechnical analysis must demonstrate there is a significant possibility that a primary structure or single-family dwelling will be damaged within three years because of shoreline erosion in the absence of such measures; or
(2) For soft structural shoreline stabilization measures a geotechnical analysis must demonstrate there is a significant possibility that a primary structure or single-family dwelling will be damaged because of shoreline erosion in the absence of such measures, but the need does not have to be as immediate as three years. (Ord. 716 § 4 (Att. A), 2021)
21.76.060 Structural shoreline stabilization – New or enlargement.
New structural shoreline stabilization, and additions that increase the size of existing structural shoreline stabilization, are prohibited, except where necessity is demonstrated per this section.
(1) To protect existing primary structures including single-family dwellings, provided:
(a) On-site drainage has been directed away from the shoreline edge first;
(b) Geotechnical analysis pursuant to WMC 21.76.090(1) provides conclusive evidence that the structure or dwelling is in danger from shoreline erosion caused by floods, winds, currents, and waves; and
(c) The structural shoreline stabilization will not result in a net loss of shoreline ecological functions pursuant to the analysis in WMC 21.73.020.
(2) To support a new non-water-dependent development, including single-family dwellings, provided:
(a) Shoreline erosion is not being caused by upland conditions, such as the loss of vegetation and drainage;
(b) Geotechnical analysis pursuant to WMC 21.76.090(1) demonstrates a need to protect the primary structure from damage due to erosion caused by natural processes such as floods, winds, currents, and waves;
(c) Nonstructural measures such as placing the development further from the shoreline, planting vegetation, or installing on-site drainage improvements are not feasible or not sufficient in protecting the primary structure; and
(d) The structural shoreline stabilization will not result in a net loss of shoreline ecological functions pursuant to the analysis in WMC 21.73.020.
(3) To support a water-dependent development, provided:
(a) Shoreline erosion is not being caused by upland conditions, such as the loss of vegetation and drainage;
(b) Geotechnical analysis pursuant to WMC 21.76.090(1) demonstrates a need to protect primary structures from damage due to erosion;
(c) Nonstructural measures, planting vegetation, or installing on-site drainage improvements are not feasible or not sufficient in protecting primary structures; and
(d) The structural shoreline stabilization will not result in a net loss of shoreline ecological functions pursuant to the analysis in WMC 21.73.020.
(4) To protect projects for the restoration of shoreline ecological functions, provided:
(a) Nonstructural measures, planting vegetation, or installing on-site drainage improvements are not feasible or not sufficient; and
(b) The structural shoreline stabilization will not result in a net loss of shoreline ecological functions pursuant to the analysis in WMC 21.73.020. (Ord. 716 § 4 (Att. A), 2021)
21.76.070 Repair or replacement of structural shoreline stabilization.
(1) Existing structural shoreline stabilization may be repaired provided:
(a) Repairs over a five-consecutive-year period involve less than 60 percent of the lineal length of the structure on the property below the ordinary high water mark;
(b) The repair is in the same place as the existing structure; and
(c) The repair does not increase the height, width, length, or depth of the existing structure.
(2) An existing structural shoreline stabilization may be replaced up to 100 percent provided:
(a) The existing structure cannot adequately perform a shoreline stabilization function;
(b) Replacement involves constructing new structure to replace existing structure;
(c) Replacement structure is with similar structure including using soft measures to replace hard measures;
(d) Replacement structure does not increase the height, width, length, or depth of the existing structure, except as may be necessary to implement soft structural shoreline stabilization;
(e) Replacement walls and bulkheads do not intrude further waterward of the ordinary high water mark and existing structure unless the residence was occupied prior to January 1, 1992, and there are overriding safety or environmental concerns, in which case the replacement structure shall abut the existing shoreline stabilization structure;
(f) The replacement structure is designed, located, sized and constructed to assure no net loss of shoreline ecological functions per an analysis in WMC 21.73.020; and
(g) A demonstration of need is provided pursuant to WMC 21.76.090(2) showing the shoreline stabilization structure is necessary to protect principal use or structure from erosion caused by floods, currents, or waves, except this requirement does not apply if soft measures are used to replace hard structure that result in significant restoration of shoreline ecological functions or processes. (Ord. 716 § 4 (Att. A), 2021)
21.76.080 Structural shoreline stabilization – Design consideration.
(1) Where structural shoreline stabilization is allowed, soft measures such as bioengineering or biotechnical measures shall be used unless it can be demonstrated such measures are not sufficient at protecting primary structures or dwellings, in which case hard measures may be used.
(2) All new, expanded or replacement shoreline stabilization measures shall be designed and constructed so that down-current banks will not be adversely affected.
(3) Shoreline stabilization measures, including riprap, shall be designed and constructed in a manner consistent with the Department of Fish and Wildlife, Corps of Engineers and/or other engineering and design specifications determined appropriate.
(4) Adequate toe protection shall be provided to ensure stability for the structure.
(5) Fill behind a hard-structural shoreline stabilization is limited to less than two cubic yards of material per linear foot of the shoreline stabilization structure. (Ord. 716 § 4 (Att. A), 2021)
21.76.090 Shoreline stabilization – Report and application requirements.
(1) Where geotechnical analysis is required under WMC 21.76.050, the analysis shall be prepared by a qualified professional and have the following information:
(a) An assessment of erosion potential including rates of erosion and estimated time frames of erosion from waves or other natural processes in the absence of shoreline stabilization;
(b) An assessment of the processes causing the erosion including on-site drainage both waterward and landward of the ordinary high water mark;
(c) An assessment of the risk shoreline erosion might cause damage to primary structures and single-family dwellings in the absence of structural shoreline stabilization;
(d) An assessment of the urgency and necessity for structural shoreline stabilization considering site-specific conditions;
(e) An assessment of the feasibility of using soft structural shoreline stabilization measures in lieu of hard measures; and
(f) Narrative on design recommendations for minimizing the use of shoreline stabilization materials and to assure no net loss of shoreline ecological functions.
(2) Where a demonstration of need is required pursuant to WMC 21.76.060, the following shall be provided:
(a) A written narrative that demonstrates a need for the shoreline stabilization structure prepared by a qualified professional.
(b) The content of the narrative shall include the following:
(i) An assessment of the necessity for structural stabilization to protect principal use or structure, considering site-specific conditions such as water depth, orientation of the shoreline, wave fetch, and location of the nearest structure;
(ii) An assessment of erosion potential resulting from the action of waves or other natural processes operating at or waterward of the ordinary high water mark in the absence of structural shoreline stabilization;
(iii) An assessment of the feasibility of using soft structural stabilization measures in lieu of hard structural shoreline stabilization measures; and
(iv) Design recommendations for minimizing impacts and ensuring that the replacement structure is designed, located, sized, and constructed to assure no net loss of shoreline ecological functions.
(3) The following are application submittal requirements for proposals involving structural shoreline stabilization:
(a) Plan and cross-section views of the existing and proposed shoreline configuration showing accurate existing and proposed topography and the ordinary high water mark;
(b) Detailed construction sequence and specifications for all materials with the sizing and placement of materials selected to accomplish the following:
(i) Protect the property and structures from erosion and other damage over the long term;
(ii) Allow safe passage and migration of fish and wildlife; and
(iii) Minimize or eliminate juvenile salmon predator habitat;
(c) Where applicable, geotechnical analysis or narrative evaluating need;
(d) Where applicable, no net loss analysis; and
(e) Where applicable, enhancement plans and monitoring and maintenance reports.
The provisions of this section shall not limit the City’s ability to establish additional submittal requirements consistent with other provisions of the Woodinville Municipal Code. (Ord. 716 § 4 (Att. A), 2021)
21.76.100 Breakwaters, jetties, groins, and weirs.
(1) Breakwaters, jetties, groins, and weirs located waterward of the ordinary high water mark are allowed only for shoreline ecological function restoration activities, such as woody debris installed in streams.
(2) Breakwaters, jetties, groins, and weirs shall be designed to protect critical areas and shall provide mitigation in accordance with a no net loss of shoreline ecological functions set forth in WMC 21.73.020. (Ord. 716 § 4 (Att. A), 2021)
21.76.110 Shoreline flood hazard reduction.
(1) Flood protection and waterway modifications are those activities occurring within the waterway and wetland areas which are designed to reduce over-bank flow of high waters. Flood protection on the Sammamish River is regulated by the Corps of Engineers through the Sammamish River Flood Control Project. King County, via the King County Flood Control District, provides maintenance and repair of flood control facilities by an agreement with the Corps of Engineers.
(2) Flood hazard reduction measures may consist of nonstructural measures, such as setbacks, land use controls, wetland restoration, dike removal, use relocation, biotechnical measures, and stormwater management programs, and of structural measures, such as dikes, levees, revetments, floodwalls, channel realignment, and elevation of structures consistent with the National Flood Insurance Program.
(3) New structural flood hazard reduction measures shall be allowed under the following conditions:
(a) When it can be demonstrated by a scientific and engineering analysis that they are necessary to protect existing development;
(b) That nonstructural measures are not feasible;
(c) That impacts to shoreline ecological functions and priority species and habitats can be successfully mitigated to assure no net loss pursuant to WMC 21.73.020; and
(d) That appropriate vegetation restoration and conservation actions are undertaken consistent with WAC 173-26-221(5).
(4) Where flood protection measures such as dikes or levees are planned, they shall be placed landward of the stream way, including associated wetlands directly interrelated and interdependent with the stream proper.
(5) Flood protection measures which result in channelization shall be avoided.
(6) New flood protection measures shall not be designed and constructed in such a manner that impacts neighboring properties or creates the need for shoreline protection structures on other properties.
(7) Levees and dikes shall be designed not to interfere with the natural pattern of ground water drainage associated with the shoreline management corridor.
(8) Levee and dike structures and stream banks shall be designed to facilitate pedestrian access to the water’s edge unless public access improvements would cause unavoidable health or safety hazards to the public, inherent and unavoidable security problems, unacceptable and unmitigable significant ecological impacts, unavoidable conflict with the proposed use, or a cost that is disproportionate and unreasonable to the total long-term cost of the development. (Ord. 716 § 4 (Att. A), 2021)
21.76.120 Fill.
(1) Fill used to create new land waterward of the ordinary high water mark is prohibited.
(2) Fill is not permitted waterward of the ordinary high water mark unless necessary for a water-dependent use or to mitigate an environmental or public safety hazard.
(3) Shoreland fills or cuts shall be designed and located so that significant damage to existing shoreline ecological functions or natural resources, or alteration of local water currents will not occur and no hazard to on-site or adjacent life, property, or natural resources systems will be created.
(4) All perimeters of fills shall be planted with vegetation, retaining walls, soil compaction as necessary, or other mechanisms designed to avoid or eliminate erosion and sedimentation impacts.
(5) Priority shall be given to fill for water-dependent uses and for public uses. In evaluating fill projects, and in designating areas appropriate for fill, such factors as total water surface reduction, navigation restriction, impediment to water flow and circulation, reduction of water quality, and destruction of habitat shall be considered.
(6) Strict aesthetic controls shall be maintained to ensure that a fill restores or enhances the natural appearance of the area where it is applied.
(7) The timing of fill construction shall be regulated to minimize damage to water quality and aquatic life.
(8) Fill Material.
(a) Fill material shall be of such quality that leachate resulting from it will not introduce contaminants to the watercourse which would violate or reduce the water quality below the existing State standards applicable at the time of development.
(b) Refuse such as broken concrete or asphalt, building debris, appliances, car bodies, vegetation, flammable material, water soluble or toxic wastes, or similar materials or the use of polluted dredge spoils, solid waste, and/or sanitary landfill materials are prohibited as fill within the shoreline management corridor.
(9) Applications for fill within the shoreline jurisdiction shall include the following information:
(a) Proposed use of the fill area;
(b) Physical, chemical, and biological characteristics of the fill material;
(c) Source of fill material;
(d) Method of placement and compaction;
(e) Location of fill relative to natural and/or existing drainage patterns and wetlands;
(f) Location of the fill perimeter relative to the ordinary high water mark;
(g) Best management practices that will be employed for erosion control or stabilization means;
(h) Type of surfacing and runoff control devices; and
(i) Contingency plan in the event of degradation of the water body when determined necessary by the City. (Ord. 716 § 4 (Att. A), 2021)
21.76.130 Dredging and disposal.
(1) New development should be placed and designed to avoid, or if that is not possible, to minimize the need for new and/or maintenance dredging.
(2) Dredging waterward of the ordinary high water mark to obtain fill material is prohibited, except where the material is necessary for the restoration of shoreline ecological functions and processes.
(3) Dredging to establish, expand, relocate, or reconfigure navigation channels and basins is allowed provided:
(a) The dredging is necessary for safe and efficient accommodation of existing navigational uses; and
(b) Significant impacts to shoreline ecological functions are minimized.
(4) Dredging to restore a previously authorized configuration is allowed if it is limited to previously dredged and/or existing authorized locations, depth, and width.
(5) All dredging and dredge material disposal shall be done in a manner which avoids or minimizes significant impacts to shoreline ecological functions and impacts which cannot be avoided should be mitigated in a manner that assures no net loss of shoreline ecological functions pursuant to the analysis prescribed in WMC 21.73.020.
(6) Dredging operations must be designed and scheduled to:
(a) Avoid impacts to aquatic life, including fish migrating, rearing, feeding and spawning;
(b) Use techniques that minimize dispersal of bottom materials; and
(c) Prevent direct and indirect adverse impacts on adjacent properties.
(7) Where dredging is for the purpose of restoring shoreline ecological functions, the site where the fill is to be placed must be waterward of the ordinary high water mark.
(8) Where dredging will extract organic materials, measures must be taken to prevent unnecessary suspension of this material in the water.
(9) Dredging and dredge disposal are prohibited within archaeological sites listed or determined eligible for listing on the Washington State Register of Historic Places.
(10) Dry Land and Water Area Deposits.
(a) Disposal of dredged material may be accomplished at approved, contained, upland disposal sites.
(b) The outside face of diked cells for dredge disposal on land shall be sloped at 1.5:1 (horizontal: vertical) or less and must be seeded with grass or other plantings to prevent erosion.
(c) Individual disposal operations shall comply with the Department of Ecology water quality certification process and the U.S. Army Corps of Engineers permit requirements.
(d) Organic material shall not wash or leach into an adjacent watercourse.
(e) Landscaping or soil stabilization techniques employed shall use native noninvasive species and shall be installed as soon as possible to retard wind and water erosion and to restore the wildlife habitat value of the site.
(f) Dredge spoils containing toxic sediments per State or Federal criteria shall be contained in diked cells of sufficient capacity to allow settling of sediments and containment so that leachate cannot enter surface or ground water.
(11) Application submittals for dredging must include the following:
(a) A written description of the purpose for the dredging;
(b) Site plan drawing outlining the area proposed for dredging including water depth;
(c) A written description of the scope of work to be performed including dredging methods, timelines, and volume;
(d) Habitat survey identifying aquatic vegetation, potential native fish spawning areas, or other physical and biological habitat parameters;
(e) Information on disposal including information on chemical and physical analysis of dredge spoil material;
(f) Anticipated future dredging, if applicable;
(g) Copies of State and Federal applications and/or approvals; and
(h) Other relevant information requested by the Director. (Ord. 716 § 4 (Att. A), 2021)