17.125.060 Standard buffer width requirements

17.125.060 Standard buffer width requirements.

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 as follows:

(a) For Category I wetlands:

Category I Type	Buffer Width
Natural Heritage wetlands	215 feet
Bog	215 feet
Estuarine	175 feet
Coastal lagoon	175 feet
Habitat score from 8 – 9 points	225 feet
Habitat score from 5 – 7 points	150 feet
Category I not meeting any of the descriptions above	125 feet

(b) For Category II wetlands:

Category II Type	Buffer Width
Estuarine	135 feet
Habitat score from 8 – 9 points	200 feet
Habitat score from 5 – 7 points	125 feet
Category II not meeting any of the descriptions above	100 feet

Category III Type	Buffer Width
Habitat score from 5 – 7 points	125 feet
Category III not meeting any of the descriptions above	75 feet

(d) For Category IV wetlands: 50 feet.

(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 five 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.

(b) Buffer Width Reduction. Buffer widths for all categories of wetlands may be reduced by 25 feet if the following mitigation measures are applied:

Disturbance	Activities That May Cause Disturbance	Measures to Minimize Impacts
Lights	Parking lots, warehouses, manufacturing, high density residential	Direct lights away from wetland
Noise	Manufacturing, high density residential	Place activity that generates noise away from wetland
Toxic Runoff	Parking lots, roads, manufacturing, residential areas, application of agricultural pesticides, landscaping	Route all new untreated runoff away from wetland; or covenants limiting use of pesticides within 150 feet of wetland; or integrated pest management program
Change in Water Regime	Any impermeable surface, lawns, tilling	Infiltrate or treat, detain and disperse runoff from impervious surfaces
Pets and Humans	Residential areas	Privacy fencing or landscaping to delineate buffer edge and to discourage disturbance of wildlife by humans and pets; and educational signage.
Dust	Tilled fields	Best management practices for dust control
Degraded Buffer	Existing degraded buffer condition	Non-native plants to be removed and replaced with native vegetation per an approved planting plan; and restoration to be bonded and monitored per SMC 17.114.250
Other as Further Defined by DOE Wetlands Guidance Documents	Other as further defined by DOE wetlands guidance documents	Other as further defined by DOE wetlands guidance documents

(Ord. 1398 § 29, 2015; Ord. 1164 § 4, 2004; Ord. 1055, 1998; Ord. 929 Ch. 10(G)(4), 1995. Formerly 17.125.040).