22.08.120 Shoreline modifications/stabilization.
Shoreline modifications are generally related to construction of a physical element such as a bulkhead, fill or vegetation removal in conjunction with development of a permitted use. Shoreline stabilization measures are those mechanisms used to prevent erosion and deterioration of shoreline areas as a result of wave, wind, tidal or flooding actions. Shoreline stabilization measures can include but are not limited to examples of shoreline modifications above and vegetation conservation, biotechnical measures, anchor trees or LWD placement, gabion and rip-rapped banks, retaining walls and sheet pilings.
A. Policies.
1. New development should be managed and designed to eliminate the need for shoreline modification or stabilization.
2. Replacement of structurally engineered stabilization measures with the same new measures should not occur unless it is associated with a water-dependent use or there is a demonstrated need based on potential loss of a legally permitted use or primary structure or there is a threat to the viability of an existing water-dependent use.
3. Whenever feasible, bioengineered and soft-shore shoreline modifications and stabilization should be explored and implemented before reverting to structurally engineered techniques.
4. New structural shoreline modifications should only be allowed as an element of a water-dependent use or when it is demonstrated to be necessary to protect an allowed primary structure or a legally existing shoreline use that is in danger of loss or substantial damage.
5. Structural shoreline modification should be allowed if it is necessary for reconfiguration of the shoreline for mitigation or restoration purposes.
6. Enhancement of impaired ecological functions should be planned for where feasible and appropriate while accommodating permitted uses. As shoreline modifications occur, all feasible measures including mitigation sequencing should be incorporated to protect ecological shoreline functions and ecosystem-wide processes.
7. In order to maintain the integrity of shoreline bluffs and bank stabilization and to eliminate the necessity of shoreline stabilization, native vegetation removal should be minimized.
8. Surface water should be tight-lined to water treatment features that would avoid contamination of the water body from lawns and yard products and would avoid bank erosion and future sloughing.
B. Regulations.
1. Bioengineered or “soft” shoreline modification or stabilization techniques shall be considered prior to those techniques that are structurally engineered. It shall be demonstrated by a critical area report including a hydrologic analysis that a bioengineered measure cannot achieve the intended purpose before a submittal and analysis of a structurally engineered measure is proposed.
2. A bioengineered shoreline modification or stabilization measure(s) shall be considered concurrent with the mitigation sequencing in BMC 22.08.020, Mitigation sequencing, and submittal of an approved critical area report that demonstrates the following:
a. Natural shoreline processes including channel migration will be maintained. The project will not result in increased beach or stream-bank erosion, alteration to, or loss of, shoreline substrate within one-quarter mile of the project area, sediment supply and transport will be maintained, migration corridors and spawning areas will not be impacted and aquatic vegetation where it exists will not be minimized.
b. Modification or stabilization techniques will not degrade critical areas or their associated buffers, especially fish and wildlife habitat conservation areas.
c. The modification or stabilization technique does not prohibit or impede the natural processes of the water body including channel migration, floodwater conveyance and storage and beach acquisition/accretion.
d. The cumulative impacts of a singular shoreline modification on that particular water body shall be analyzed prior to granting of said modification technique.
e. The result of the measure would result in no net loss of shoreline ecological function in the riparian and/or near-shore areas.
3. Structural shoreline modification and/or stabilization shall be allowed if it is necessary for reconfiguration of the shoreline for mitigation, restoration or emergency purposes.
4. In all other cases, a structurally engineered shoreline modification or stabilization measure, including a replacement, shall be allowed when all of the following are demonstrated:
a. Said modification or stabilization measure(s) are necessary as an element of a water-dependent use;
b. It can be demonstrated by a geotechnical/hydrologic report that a bioengineered modification or stabilization technique cannot sustain impacts of wave, current and tidal energy and erosion;
c. It is necessary to protect an existing primary structure demonstrated by a geotechnical analysis that concludes that a given structure is in danger of loss or damage from uncharacteristic or a sudden increase in erosional processes or poses a threat to health, safety and welfare of the general public (loss of yard, grass, landscaping and vegetation, pier abutment, accessory buildings or structures does not constitute an allowance for a structurally engineered measure);
d. For shorelines on Lake Whatcom only; the structurally engineered measure shall be installed above the level of the OHWM; and
e. The requirements in subsections (B)(2)(a) through (e) of this section have been met.
5. Surface water shall be managed in such a manner that it does not create additional pollutant loading to an adjacent water body and/or cause accelerated bank erosion or bank sloughing. [Ord. 2013-02-005 § 2 (Exh. 1)].