19.37.110 Standard wetland buffer width requirements

19.37.110 Standard wetland buffer width requirements.

1. The following buffer widths listed in Tables 37.2 and 37.3 apply to all wetlands within the city of Everett. Buffer widths have been established in accordance with the best available science. Buffers are based on the category of wetland and the habitat score as determined by a qualified wetland professional using the Washington State Wetland Rating System for Western Washington: 2014 Update (Ecology Publication No. 14-06029, or as revised and approved by Ecology).

When feasible, a relatively undisturbed vegetated corridor at least one hundred feet wide must be protected between the wetland and any nearby priority habitat. Presence or absence of a nearby habitat must be confirmed by a qualified biologist. If there is a presence of a nearby priority habitat and if the wetland has a habitat function score of six or more, a one-hundred-foot-wide relatively undisturbed, vegetated corridor must be provided between the wetland and other priority habitats if there is a corridor available to provide. If a corridor is available and is not set aside into an easement or tract, the buffers listed in Table 37.2 apply.

User instructions: Use the following two tables to determine wetland buffers. Table 37.2 includes the standard buffers without utilizing the general mitigation measures described below. The reduced buffers in Table 37.3 apply to projects when the applicant elects to incorporate all general mitigation measures. If priority habitat is not present, use Table 37.3.

Table 37.2: Standard Wetland Buffers without General Mitigation Measures
CRITICAL AREA	BUFFER WIDTHS (feet)
WETLAND CATEGORY	HABITAT FUNCTION SCORES
WETLAND CATEGORY	3-5	6-7	8-9
I	100	150	300
Based on total score or forested
I	250	300
Bogs
I	200
Estuarine
II	100	150	300
Based on total score
II	150
Estuarine
III	80	150	300
IV	50

Table 37.3: Reduced Wetland Buffers When General Mitigation Measures Are Applied
WETLAND CATEGORY	WETLAND TYPE	HABITAT FUNCTION SCORES
		3-5	6-7	8-9
		BUFFER WIDTHS (in feet)
I	All including forested except those listed below	75	110	225
I	Bogs	190	225
II	All except estuarine	75	110	225
II	Estuarine	110
III		60	110	225
IV		40

2. The standard buffer widths required by this chapter presume the existence of a relatively intact native vegetated community including native tree cover, shrub understory and ground cover. If the existing buffer is unvegetated, sparsely vegetated, or vegetated with invasive species, the buffer vegetation shall be enhanced or restored to the width required by this section. The vegetation shall include native plant communities that are appropriate for the Puget Lowland ecoregion or with a plant community that provides similar functions.

B. Increased Standard Wetland Buffer Width. The minimum buffer width stated in subsection A of this section shall be increased:

1. When the minimum buffer for a wetland extends into an area with a slope of greater than twenty-five percent, the buffer shall be the greater of:

a. The minimum buffer for that particular wetland; or

b. Twenty-five feet beyond the point where the slope becomes twenty-five percent or less for at least a horizontal distance of ten feet;

2. When the wetland is used by salmonids, plant and/or animal species proposed or listed by the federal government or state as endangered, threatened, rare, candidate, sensitive or monitored; or has critical or outstanding potential habitat for those species or has unusual nesting or resting sites such as heron rookeries or raptor nesting trees, and the increased buffer is necessary to protect such habitat;

3. When a habitat assessment or habitat management plan is required by EMC 19.37.190 and an increased buffer is necessary to protect critical habitat or affected species, the buffer shall be the buffer in the approved habitat assessment or habitat management plan;

4. When the adjacent land is classified as a geologically hazardous area, the buffer shall be the greater of the standard wetland buffer or the setback buffer required by EMC 19.37.080;

5. When the standard buffer has minimal or degraded vegetative cover that cannot be improved through enhancement; or

6. When the city finds, based upon a site-specific wetland analysis, that impacts on the wetland from a proposed development can only be mitigated by a greater buffer width.

C. General Mitigation Measures. Implementation of all of the following general mitigation measures allows use of the reduced wetland buffers listed in Table 37.3:

1. Direct lights away from the wetland.

2. Locate activity that generates noise away from the wetland.

3. Route all new, untreated runoff away from the wetland while ensuring wetland is not dewatered.

4. Establish covenants limiting use of pesticides within one hundred fifty feet of the wetland.

5. Apply integrated pest management.

6. Retrofit stormwater detention and treatment for roads and existing adjacent development.

7. Prevent channelized flow from lawns that directly enters the buffer.

8. Infiltrate or treat, detain, and disperse into buffer new runoff from impervious surfaces and new lawns.

9. Use privacy fencing; plant dense vegetation to delineated buffer edge and discourage disturbance using vegetation appropriate for the ecoregion; place the wetland and its buffer in a separate tract.

10. Use best management practices to control dust.

D. Where wetland functions have been improved due to voluntary implementation of an approved stewardship, restoration and/or enhancement plan that is not associated with required mitigation or enforcement, the standard wetland buffer width shall be determined based on the previously established wetland category and habitat score as documented in the approved stewardship and enhancement plan. (Ord. 3676-19 § 14, 2019; Ord. 3457-15 §§ 3, 4, 2015; Ord. 2909-06 § 11, 2006.)