Shoreline stabilization includes actions taken to address erosion impacts to property, dwellings, businesses, or essential structures caused by manmade processes such as boat wakes and natural processes, such as current, flood, wind, or wave action. These include structural and nonstructural methods. Nonstructural methods include building setbacks, relocation of the structure to be protected, erosion and ground water management, planning and regulatory measures to avoid the need for structural stabilization. Structural methods include "hard" and "soft" structural stabilization measures.
A. Maintenance and Repair. Normal maintenance and repair actions are not exempt from substantial development permits if they cause substantial adverse effects to shoreline resources or the environment. Additions to or increases in size of existing shoreline stabilization measures shall be considered new structures. Some shoreline stabilization measures for single-family residences may be exempt from a shoreline substantial development permit in accordance with WAC
173-27-040(2). However, such measures must comply with the provisions of this SMP.
1. An existing shoreline stabilization structure shall not be replaced with a similar structure unless there is need to protect primary structures from erosion caused by currents or waves and a nonstructural measure is not feasible. The replacement structure shall be designed, located, sized, and constructed to minimize harm to ecological functions. Replacement walls or bulkheads shall not encroach waterward of the OHWM unless there are overriding safety or environmental concerns. In such cases, the replacement structure shall abut the existing shoreline stabilization structure.
2. When an existing bulkhead is being repaired or replaced by construction of a vertical wall fronting the existing wall, it shall be constructed no farther waterward of the existing bulkhead than is necessary for construction of new footings. When a bulkhead has deteriorated such that an OHWM has been established by the presence and action of water landward of the bulkhead, then the replacement bulkhead must be located at or landward of the actual OHWM.
3. Replacement bulkheads may be built to the height of the original bulkhead.
B. New Development and/or Structures.
1. New development shall, where feasible, be located and designed to eliminate the need for concurrent or future shoreline stabilization. New non-water-dependent development that would require shoreline stabilization that would cause significant adverse impacts to adjacent or down-current properties is prohibited.
2. New development, including single-family residences, that includes structural shoreline stabilization will not be allowed unless all of the conditions below are met:
a. The need to protect the development from damage due to erosion caused by natural processes, such as currents and waves, and by manmade processes such as boat wakes, is demonstrated through a geotechnical report.
b. The erosion is not being caused by upland conditions, such as loss of vegetation and drainage.
c. Nonstructural measures, such as placing the development farther from the shoreline, planting vegetation, low impact development measures, or installing on-site drainage improvements, are not feasible or not sufficient.
d. The structure will not result in a net loss of shoreline ecological functions.
3. New development on steep slopes or bluffs shall be set back sufficiently to ensure that shoreline stabilization will not be needed during the life of the structure, as demonstrated by a geotechnical analysis.
C. New or Expanded Shoreline Stabilization Measures.
1. New stabilization measures are not allowed except to protect or support an existing or approved development, as necessary for human safety, for the restoration of ecological functions, or for hazardous substance remediation pursuant to Chapter
70.105D RCW. The construction of a bulkhead for the primary purpose of retaining or creating dry land that is not specifically authorized as a part of the permit is prohibited.
2. New or enlarged structural shoreline stabilization measures for an existing development or residence shall not be allowed unless there is conclusive evidence, documented by a geotechnical analysis, that the structure is in danger from shoreline erosion caused by currents, waves, or boat wakes. Normal sloughing, erosion of steep bluffs, or shoreline erosion itself, without a geotechnical report, is not demonstration of need. The geotechnical report must include estimates of erosion rates and damage within three years and must evaluate on-site drainage issues and address drainage problems away from the shoreline edge before considering structural shoreline stabilization. The project design and analysis must also evaluate vegetation enhancement and low impact development measures as a means of reducing undesirable erosion.
3. "Hard"structural shoreline stabilization measures, such as bulkheads, are not allowed unless the applicant can demonstrate through a geotechnical report that "soft" structural measures such as vegetation or beach enhancement, or nonstructural measures, such as additional building setbacks, are not feasible.
4. Where structural shoreline stabilization measures are demonstrated to be necessary, the size of stabilization measures shall be limited to the minimum necessary. The city's shoreline administrator may require that the proposed structure be altered in size or design or impacts otherwise mitigated. Impacts to sediment transport shall be avoided or minimized.
5. The city's shoreline administrator will require mitigation of adverse impacts to shoreline functions such as the inclusion of vegetation conservation as part of shoreline stabilization, where feasible. In order to determine acceptable mitigation, the city's shoreline administrator may require the applicant to provide necessary environmental information and analysis, including a description of the existing OHWM, based on field indicators. The determination of the OHWM is based on a site-specific investigation using field indicators and in case of a disagreement as to its location, the ultimate decision on the OHWM shall rest with Ecology. The OHWM determination along with a restoration plan outlining how proposed mitigation measures would result in no net loss of shoreline ecological functions shall be submitted for review.
6. Shoreline stabilization measures that incorporate ecological restoration through the placement of rocks, gravel or sand, and native shoreline vegetation may be allowed. Soft shoreline stabilization that restores ecological functions may be permitted waterward of the OHWM.
7. Following completion of shoreline modification activities, disturbed shoreline areas shall be restored to preproject conditions to the greatest extent possible. Vegetation conservation measures, including the planting of native vegetation along the shoreline, are a condition of all new bulkhead and replacement construction. Plantings shall consist of native grasses, shrubs, and trees as approved by the city's shoreline administrator in keeping with preexisting or typical naturally occurring bank vegetation. Vegetation shall be fully reestablished within three years. All revegetation projects shall include a program for monitoring and maintenance. Areas which fail to adequately reestablish vegetation shall be replanted with approved plants until the plantings are viable.
D. Design of Shoreline Stabilization Measures.
1. Bulkhead design and development shall conform to all other applicable city and state agency policies and regulations, including the Washington State Department of Fish and Wildlife criteria governing the design of bulkheads.
2. Gabions (wire mesh filled with concrete or rocks) are prohibited, except as a conditional use where it is determined that gabions are the least environmentally disruptive method of shoreline stabilization.
3. Stairs and other allowed structures may be built as integral to a bulkhead but shall not extend waterward of the bulkhead or structure unless it is necessary to access the shoreline or a use or structure is otherwise allowed over water.
4. Bulkheads shall be designed to permit the passage of surface or ground water without causing ponding or over-saturation of retained soil/materials of lands above the OHWM.
5. Adequate toe protection and proper footings shall be provided to ensure bulkhead stability without relying on additional riprap.
E. Materials and Dimensional Standards. New bulkheads and other shoreline stabilization structures shall not be constructed higher than twenty-four inches above the OHWM or, if the bulkhead is set back from the shoreline, twenty-four inches above grade at the base of the bulkhead or structure. On steep slopes, new bulkheads may be built taller than twenty-four inches high if necessary to meet the existing slope.
F. Essential public facilities may deviate from these standards so long as they provide proof to the city, state and federal agencies that the facility cannot be reasonably built or maintained by meeting these standards and adequate mitigation is provided to compensate for any ecological impacts.
(Ord. 1295 § 10 (Exh. 1B) (part), 2011; Ord. 1427 § 3 (Exh. C) (part), 2019)