17.125.060 Standard buffer width requirements – SMP

17.125.060 Standard buffer width requirements – SMP.

Buffers shall be required for all wetlands regulated by this chapter. Required wetland buffer widths are as stated in this section.

(1) Required widths for wetland buffers are identified in the following tables:

(a) For Category I wetlands:

	Buffer width (in feet) based on habitat score
Wetland Category	3 – 5	6 – 7	8 – 9
Category I: Based on Total Score	75	110	225
Category I: Bogs and Wetlands of High Conservation Value	190		225
Category I: Interdunal	225
Category I: Forested	75	110	225
Category I: Estuarine and Coastal Lagoons	150

(b) For Category II wetlands:

	Buffer width (in feet) based on habitat score
Wetland Category	3 – 5	6 – 7	8 – 9
Category II: Based on Total Score	75	110	225
Category II: Interdunal Wetlands	110

	Buffer width (in feet) based on habitat score
Wetland Category	3 – 5	6 – 7	8 – 9
Category III: All	60	110	225

(d) For Category IV wetlands:

	Buffer width (in feet) based on habitat score
Wetland Category	3 – 5	6 – 7	8 – 9
Category IV: All	40

(2) Measurement. The buffer shall be measured horizontally in a landward direction from the wetland edge. Where lands adjacent to a stream or wetland display a continuous slope of 25 percent or greater, the buffer shall include all such sloping areas. Where the horizontal distance of the sloping area is greater than the required standard buffer, the buffer shall be extended to a point 25 feet beyond the top of the bank of the sloping area.

(a) Priority Habitat Areas. If a Category I or II wetland with habitat score greater than 20 points is located within 300 feet of a priority habitat area as defined by the Washington State Department of Fish and Wildlife, the buffer established by subsection (1) of this section shall be increased by 50 feet unless:

(i) The applicant provides a relatively undisturbed vegetated corridor at least 100 feet wide between the wetland and all priority habitat areas located within 300 feet of the wetland. The corridor shall be protected for the entire distance between the wetland and the priority habitat through a conservation easement, native growth protection easement or the equivalent; and

(ii) The applicable mitigation measures in subsection (4) of this section are provided.

(b) Habitat for Endangered or Threatened Species, or Species of Local Importance. If the wetland contains documented habitat for endangered or threatened species, or species of local importance, the community development department shall establish the appropriate buffer based on a habitat assessment to ensure that the buffer provides adequate protection for the species.

(a) Averaging Buffer Widths. The width of a buffer may be averaged, thereby reducing the width of a portion of the buffer and increasing the width of another portion, if the community development director determines that all of the following requirements are met:

(i) The ecological structure and function of the buffer after averaging is equivalent to or greater than the structure and function before averaging;

(ii) The total area of the buffer after averaging is equivalent to or greater than the area of the buffer before averaging;

(iii) The additional buffer is contiguous with the standard buffer;

(iv) If the buffer averaging allows a structure or landscaped area to intrude into the original buffer, the resulting intrusion shall extend no more than 15 feet into the original buffer area; and

(v) No part of the width of the resulting buffer is less than 65 percent of the required buffer.

(5) Site development standards for lands adjacent to buffers shall be implemented as provided below to reduce proximity impacts. If mitigation site development standards are not implemented then a 33 percent increase in the width of buffers is required.

Disturbance	Activities That May Cause Disturbance	Measures to Minimize Impacts
Lights	Parking lots, warehouses, manufacturing, commercial, residential	Direct lights away from wetland
Noise	Manufacturing, commercial, residential	Place activity that generates noise away from wetland; activities that generate relatively continuous disruptive noise above 65 dBA shall establish a noise barrier at the edge of the buffer capable of reducing noise levels as close as feasible to background levels
Toxic Runoff	Parking lots, roads, manufacturing, residential areas, application of agricultural pesticides, landscaping	Route all new untreated runoff away from wetland; establish covenants or other agreements limiting use of pesticides within 150 feet of wetland; implement integrated pest management program
Change in Water Regime	Any impermeable surface, lawns, tilling	Infiltrate or treat, detain and disperse into buffer and new runoff from impervious surfaces and new lawn
Pets and Humans	Residential areas	Install fencing or plant dense vegetation and install educational signage to delineate buffer edge and to discourage disturbance of wildlife by humans and pets; place wetland and its buffers in a separate tract or protect with a conservation easement
Dust	Tilled fields	Best management practices for dust control
Disruption of Corridors or Connections	Existing degraded buffer condition	Nonnative plants to be removed and replaced with native vegetation per an approved planting plan; and restoration to be bonded and monitored per SMC 17.114.190
		Other as further defined by DOE wetlands guidance documents

(6) Buffer Exclusion. An area within the standard buffers may be excluded if the area is functionally and effectively disconnected from the wetland by a road, railroad or other substantially developed surface of sufficient width and with use characteristics such that buffer functions are not provided. The equivalent of the area excluded shall be provided elsewhere adjacent to the wetland through buffer averaging provisions not subject to the limit on area or width. Where the entire area excluded cannot feasibly be provided, other mitigation may be approved to provide equivalent function. This provision shall not apply to such a facility within a development proposal or contiguous ownership that can be feasibly relocated to accommodate standard buffers.

(7) Reach Based Alternative Buffer Width Requirements. Within Shoreline Management Act jurisdiction the director may implement the reach based alternative buffer standards in SMC 17.130.060(6) without a variance. (Ord. 1475 § 2 (Att. B), 2019; Ord. 1373 §§ 35, 36, 2014; Ord. 1164 § 4, 2004; Ord. 1055, 1998; Ord. 929 Ch. 10(G)(4), 1995. Formerly 17.125.040).