14.50.660.02 Regulations | Aberdeen Municipal Code

14.50.660.02 Regulations.

1. New development that requires shoreline stabilization measures that cause significant impacts to adjacent or down-current properties and shorelines shall not be allowed.

2. Land subdivisions shall be designed to assure that future development of the created lots will not require shoreline stabilization structures for reasonable development to occur.

3. New development on steep slopes or bluffs shall be set back sufficiently to ensure that shoreline stabilization structures are unlikely to be necessary during the life of the development. The shoreline administrator may require a geotechnical analysis to demonstrate this.

4. If new development is proposed on state-owned aquatic lands, consultation with WDNR will be required before final design is completed.

1. The following items distinguish between maintenance and repair of a shoreline stabilization structure and a new structure:

a. Maintenance and repair include modifications to an existing shoreline stabilization structure that is designed to ensure the continued function of the existing structure.

b. A modification that increases the size of the existing shoreline stabilization structure shall be considered a new structure, not maintenance or repair.

c. Replacement of greater than fifty (50) percent of the linear length of an existing shoreline stabilization structure, as measured on a cumulative basis since the structure was established, is not considered repair or maintenance and is considered a new structure.

d. Removal of an existing shoreline stabilization structure, including its footing or bottom course of rock, prior to the placement of a new structure, is considered a new structure for the purposes of this section. Removal of only material above the footings or bottom course of rock is not considered a new structure and it qualifies as maintenance and repair.

e. The placement of a new shoreline stabilization structure landward of a failing shoreline stabilization structure shall be considered a new structure subject to all the requirements of Section 14.50.660, not maintenance or repair.

2. When an application proposes repair and maintenance of an existing legally established shoreline stabilization structure, it is subject to the following standards:

a. Repair and maintenance of existing shoreline stabilization structures must be consistent with the requirements of Section 14.50.430.

b. Areas of temporary disturbance within the shoreline buffer associated with maintenance and repair shall be restored to their pre-project condition within thirty (30) days.

3. Repair of shoreline stabilization structures meeting all the criteria for exemption from a shoreline substantial development permit must still comply with subsection (E) of this section and the SMP.

1. Replacement or enlargement of an existing shoreline stabilization structure shall be considered a new structure.

2. For purposes of this section, “replacement” means the construction of a new structure to perform the shoreline stabilization function of an existing structure that can no longer adequately serve its purpose.

1. New shoreline stabilization structures shall only be allowed when demonstrated to be necessary as follows:

a. To protect an existing primary structure, including a residence, if there is conclusive evidence documented by a geotechnical analysis that the primary structure is in danger from shoreline erosion caused by natural processes. Normal sloughing, erosion of steep bluffs or shoreline erosion in itself, without a geotechnical analysis, is not demonstration of need. The geotechnical analysis shall evaluate on-site drainage issues and address problems away from the OHWM before considering new shoreline stabilization structures.

b. In support of water-dependent development when all of the conditions below apply:

(1) Site erosion is not being caused by upland conditions, such as drainage and the loss of vegetation;

(2) Nonstructural measures, such as planting vegetation or installing on-site drainage improvements, are not feasible or sufficient to address erosion causes or impacts adequately; and

(3) The need to protect primary structures from damage due to erosion is demonstrated through a geotechnical analysis.

c. In support of new non-water-dependent development, including residences, when all of the conditions from water-dependent development from subsection (D)(1)(b) of this section apply and nonstructural measures, such as placing the proposed development farther from the shoreline, are not feasible or sufficient to address the erosion impacts adequately.

d. To protect historic or cultural resources, or as part of restoration or hazardous substance remediation projects pursuant to Chapter 70.105D RCW, when nonstructural measures, such as planting vegetation or installing on-site drainage improvements, are not feasible or sufficient to adequately address the causes of erosion or avoid continued degradation, disturbance, or erosion of a site.

2. A geotechnical analysis is not required when an applicant proposes to replace an existing shoreline stabilization structure with a softer measure, so long as the applicant demonstrates through site photographs and a written narrative the need to protect the primary uses or structures from erosion caused by waves or other natural processes operating at or waterward of the OHWM.

3. Replacement of hard shoreline stabilization structures shall not encroach waterward of the OHWM or the existing shoreline stabilization measures unless the primary residence was constructed prior to January 1, 1992, and there are overriding safety or environmental concerns. In such cases, the replacement for the shoreline stabilization structure shall be attached to and waterward of the existing structure. All other replacement of hard stabilization structures shall be located at or landward of the existing shoreline stabilization measure.

1. Shoreline stabilization measures shall not result in a net loss of shoreline ecological function.

2. When a hard or soft shoreline stabilization structure is demonstrated to be necessary, the following design standards shall be incorporated as part of the design:

a. Impacts to sediment transport shall be avoided or minimized.

b. Shoreline stabilization structures shall be the minimum size necessary by height, depth and mass and not extend waterward more than the minimum amount needed to achieve effective stabilization, except for those elements that enhance shoreline ecological functions and minimize impacts.

c. Soft structural shoreline stabilization measures shall be used to the maximum extent feasible for new, enlarged or replacement shoreline stabilization structures, unless demonstrated insufficient to protect primary structures in a geotechnical analysis.

d. When feasible, hard structural shoreline stabilization measures shall be limited to the portion of the site necessary to protect primary structures or connect to existing shoreline stabilization measures on adjacent properties.

e. All clearing, grading and filling associated with shoreline stabilization structures shall be conducted landward of the OHWM to the maximum extent feasible unless it is infeasible due to safety or environmental concerns.

f. Fill behind shoreline stabilization structures is limited to one (1) cubic yard per running foot of stabilization. Filling in excess of this amount shall be subject to the regulations in Section 14.50.620 and require a shoreline substantial development permit or shoreline conditional use permit.

g. All approved new, enlarged or replacement shoreline stabilization structures shall be designed using BMPs, including WDFW’s Integrated Streambank Protection Guidelines, and minimize and mitigate unavoidable adverse impacts to ecological functions, consistent with Section 14.50.430.

h. All new, enlarged or replacement shoreline stabilization structures shall mitigate adverse impacts to ecological functions. Mitigation measures shall be identified by the project proponent as part of the project application and may be supplemented by local, state or federal agencies, depending on the level of impact.

i. When a new shoreline stabilization structure is proposed on a site where adjacent properties do not have shoreline stabilization structures, the new structure shall tie in with the existing contours of the adjoining properties, as feasible, to prevent erosion of the neighboring land.

j. When a new shoreline stabilization structure is proposed on a site where adjacent properties have shoreline stabilization structures, the new structure may tie in with the existing structures on the adjoining properties. The new structure shall minimize, to the maximum extent feasible, the portion of the new structure that is waterward of the OHWM to connect to the existing structures.

k. Shoreline stabilization structures shall be designed to ensure the project remains stable during storm and flood events on rivers and wave conditions on lakes.

l. Shoreline stabilization shall be designed not to significantly interfere with normal surface or subsurface drainage into the adjacent water body.

m. All shoreline stabilization shall be designed to avoid hazards to navigation.

n. Shoreline stabilization shall be designed to ensure that it does not restrict appropriate public access to the shoreline. Where a shoreline stabilization structure is required at a public access site, provisions for safe access to the water shall be incorporated into the design.

o. Stairs or other water access measures may be incorporated into shoreline stabilization design, but they shall not extend waterward of the OHWM.

F. Submittal Requirements. In addition to submitting an application for the appropriate shoreline permit, the applicant shall submit a geotechnical analysis prepared by an engineer licensed by the state as part of a request to construct a new, enlarged or replacement shoreline stabilization structure. This analysis must include:

1. An assessment of the need for the shoreline stabilization structure based on site-specific conditions such as water depth, orientation of the shoreline, wave fetch or flow velocity and the location of the nearest shoreline stabilization structure.

2. The estimated time frames and rates of erosion, to convey the urgency associated with the specific situation.

3. An explanation of why subsections (D)(1)(b) and (D)(1)(c) of this section are not sufficient to address erosion issues.

4. Detailed construction plans for all shoreline stabilization structures, including, but not limited to, the following:

a. Plan and cross-section views of the existing and proposed shoreline configuration, showing the OHWM and accurate existing and proposed topography;

b. A detailed construction sequence and specifications for all materials; and

c. A mitigation and monitoring plan to ensure no net loss of shoreline functions.