The city finds that wetlands perform many important biological and physical functions that benefit the city and its residents, including but not limited to: helping to maintain water quality; storing and conveying stormwater and floodwater; recharging ground water; providing important fish and wildlife habitat; and serving as areas for recreation, education and scientific study and aesthetic appreciation. Protection of wetlands is, therefore, necessary to protect public health, safety, and general welfare.

This chapter contains standards to manage development in association with the city's wetland resources and enhance and restore wetlands where possible. The intent of these regulations is to avoid and minimize wetland impacts where avoidance and minimization is feasible and reasonable. In appropriate circumstances, impacts to wetlands resulting from regulated activities may be compensated for, consistent with this chapter. The city's overall goal is to achieve no net loss of wetland function and value, and net acreage may be considered in achieving the overall goal.

It is the intent of this chapter to implement the goals and policies of the city comprehensive plan, including those pertaining to natural features and environmental protection; aesthetics and community character; opportunities for economic development; creating a balanced transportation system; ensuring adequate public facilities; and achieving a mix of land use types and densities consistent with the city's land use plan.

It is the further intent of this chapter to establish special standards for the protection of wetlands and potential habitat of anadromous fish in compliance with the Washington Growth Management Act of 1990 (Chapter 36.70A RCW and its amendments and WAC 365-195-900 through 365-195-925) and best available science requirements.

The wetland management provisions of this chapter apply to any regulated activity (Section 17.52B.030) potentially affecting a wetland or its buffer unless otherwise exempt under Section 17.52B.040.

To avoid overlap and duplication, all city permit applications leading to the development or alteration of land, including but not limited to applications for: clearing and grading; subdivision or short subdivision, building permit, planned unit development; shoreline substantial development; variance and conditional use, shall be subject to and coordinated with the wetland requirements of this chapter and the Mukilteo Zoning Code, Chapter 17.13, Project Permit Review Process.

Nonproject actions, including but not limited to rezones, annexations, and adoption of plans and programs, shall be required to comply with the Growth Management Act (GMA), Chapter 36.70A RCW, including submittal of appropriate wetland information as determined by the city according to this chapter.

This chapter shall apply as any other overlay to development or land use regulations established by the city. In the event of a conflict between regulations in this chapter and any other city code, the regulation, which provide greater protection to environmentally sensitive areas shall apply.

Removing, excavating, disturbing or dredging soil, sand, gravel, minerals, organic matter or materials of any kind;

Dumping, discharging or filling any material;

Draining, flooding or disturbing the water level or water table;

Alteration, construction, reconstruction, or demolition of any structure or infrastructure, including driving pilings or placing obstructions;

Destroying or altering wetland vegetation through clearing, harvesting, shading or planting vegetation that would alter the wetland or buffer character; provided, that these activities are not part of a forest practice governed under Chapter 76.09 RCW and its rules;

Activities that result in significant changes in water temperature, physical or chemical characteristics of the wetland or buffer, including water quantity and quality, soil flow, or natural contours;

Any other activity potentially affecting a wetland or wetland buffer not otherwise exempt from this chapter; and

Work to maintain wetlands intentionally created from nonwetland areas as mitigation for wetland impacts.

The following activities that occur within wetlands and their buffers shall be exempt from this chapter:

No private or public entity shall undertake exempt activities as listed in this section prior to providing the city written notification of their intent to proceed with an exempt activity. The city shall verbally confirm the activity is exempt and where needed provide written authorization within thirty days of the receipt of the written notice.

In case of any question as to whether a particular activity is exempt from the wetland provisions of this chapter, the city's determination shall prevail and shall be determinative.

Notwithstanding the exemptions provided by this subsection, any otherwise exempt activity impacting a wetland and buffer should meet the purpose and intent of this chapter and should consider on-site alternatives that avoid or minimize impacts.

The city shall maintain wetland maps showing the approximate location and extent of wetlands within city jurisdiction. These maps will only show wetlands identified to date, and shall be used only as a general guide to assist property owners. The location and extent of wetlands are determined on a lot-by-lot, project-by-project basis, and if a wetland is not shown on the inventory map, that does not necessarily mean wetlands do not occur on the lot. The city will update the wetland inventory map as wetlands are mapped in the field and submitted by applicants to the city.

The wetland boundary and type shall be determined by a qualified wetland specialist according to the wetland delineation procedures as defined in the definitions, Chapter 17.08. In the event of any conflict between the wetland location or designation shown on the city's map and the location or designation as determined in the field by a qualified wetland specialist using the defined wetland delineation procedures, the field determination shall control.

Preapplication Conference. All applicants are encouraged to meet with the city prior to submitting an application subject to the wetland provisions of this chapter. The purpose of this meeting shall be to discuss the wetland requirements, process and procedures; to review the critical areas checklist and any conceptual plans prepared by the applicant; to identify potential wetlands impacts and mitigation measures; and to familiarize the applicant with state and federal wetland programs and permitting process. Such conference shall be for the convenience of the applicant and any recommendations shall not be binding on the applicant or the city. Prior to the preapplication meeting, applicants shall identify and rate wetlands on the site, consider design options to avoid and minimize impacts to wetlands or buffers, assess the likely impacts to wetlands and buffers, and consider mitigation options as discussed in the Mukilteo critical areas mitigation program (CAMP).

Wetland Delineation Report. If the city determines that wetland or buffer impacts might occur as a result of the proposal, a wetland delineation report, as defined in Chapter 17.08, must be submitted to the city for review prior to the issuance of a development permit pursuant to Chapter 17.13, project permit review process. The report must be prepared in accordance with city permit application requirements pursuant to Chapter 17.13 and incorporate best available science as defined in Chapter 17.08. The report will analyze the extent, type, and function of wetlands and buffers on any site where regulated or exempt activities are proposed. The report will also be used by the city to determine the appropriate wetland type and buffer requirement for the wetland, and to assist the city in determining appropriate mitigation if required.

Wetland Specialist. A qualified wetland specialist as defined in Chapter 17.08 shall prepare all reports and studies required of the applicant by this chapter. The city may retain a qualified wetland specialist, at the expense of the applicant, to review and confirm the applicant's reports, studies, and plans.

This section is not intended to create a separate wetland permit process for development proposals. To the extent possible, and pursuant to Chapter 17.13, the city shall consolidate and integrate the review and processing of wetland-related aspects of proposals with other land use and environmental considerations and approvals.

Wetland delineations shall be considered valid for five years following the reviewing agency verification. The buffer required by the critical areas ordinance in effect at the time of complete permit application shall apply.

Classification. Wetlands shall be classified as Category I, II, III or IV using the 2014 Washington State Department of Ecology's Wetland Rating System for Western Washington, Publication No. 04-06-025, or as amended hereafter. Identification of wetlands and delineation of their boundaries pursuant to this chapter shall be done in accordance with the approved federal wetland delineation manual and applicable regional supplements. All areas within the city meeting the wetland designation criteria in that procedure are hereby designated critical areas and are subject to the provisions of this chapter.

Sources for a preliminary identification of wetlands include, but are not limited to:

The establishment of wetland buffer areas shall be required for all development proposals and activities adjacent to wetlands to protect the functions and integrity of the wetland. Buffers between regulated activities and wetlands help stabilize soil and prevent erosion, filter suspended solids and nutrients and harmful toxic substances, moderate effects of stormwater runoff, support and protect plant and animal species and habitats, enhance plant and wildlife diversity, and discourage adverse human effects in the wetland.

Buffers are not intended to be established or to function independently of the wetland; they are established to protect.

The establishment of a buffer or buffer mitigation shall not prevent a use or activity that would otherwise be permitted in the wetland or buffer as allowed in subsections H and I of this section. Buffer mitigation in the Mukilteo Habitat Reserve (MHR) is an exception to this section, and is managed through the provisions in the Mukilteo CAMP.

Buffer Requirements. The standard buffer widths in Table 1—Wetland Buffer Widths have been established in accordance with the best available science. They 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.

Increased Wetland Buffer Area Width. Buffer widths shall be increased on a case-by-case basis as determined by the planning director when a larger buffer is necessary to protect wetland functions and values. This determination shall be supported by appropriate documentation showing that it is reasonably related to protection of the functions and values of the wetland. The documentation must include but not be limited to the following criteria:

Measurement of Wetland. All buffers shall be measured perpendicular from the wetland boundary as surveyed in the field. The buffer for a wetland created, restored, or enhanced as compensation for approved wetland alterations shall be the same as the buffer required for the category of the created, restored, or enhanced wetland. Only fully vegetated buffers will be considered. Lawns, walkways, driveways, and other mowed or paved areas will not be considered buffers or included in buffer area calculations.

Buffer Averaging. The widths of buffers may be averaged if this will improve the protection of wetland functions or if it is the only way to allow for reasonable use of a parcel. There is no scientific information available to determine if averaging the widths of buffers actually protects wetland functions; therefore, averaging shall only be allowed in the below-listed situations. Averaging may be used in conjunction with any of the other provisions for reduction in buffers including off-site buffer mitigation through use of the MHR.

The planning director may authorize the following low impact uses and activities within a wetland and wetland buffer upon showing that said uses or activities will be performed in a manner that will not adversely disturb the wetland, significantly increase the impervious surface of the buffer, or decrease the functions of the associated wetland: unpaved pedestrian trails, viewing platforms, interpretative signage, existing utility easements without a maintenance road and little or no vegetation management, and the boring of underground utilities pursuant to best management practices. Uses permitted within the buffer shall be located in the outer portion of the buffer as far as possible from the wetland. Trails should be located in the outer twenty-five percent of the buffer, avoid significant trees and should be no more than five feet wide with a pervious surface.

Except where previously approved stormwater facilities were located in wetlands, all new stormwater management facilities shall be limited to vegetation-lined swales designed for stormwater management and stormwater dispersion outfalls; provided, that they are placed within the outer twenty-five percent of the buffer of a Category III and IV wetland only. Stormwater detention ponds and outlet structures shall not be allowed in wetlands or their buffers. The outer twenty-five percent of the buffer of a Category III and IV wetland can be used for stormwater flow path and dispersion.

Buffers shall be shown on the development site plans or final plat maps along with the notation requirements identified in Section 17.52.035, Native growth protection areas (NGPA) and buffers.

If an existing property has a previously delineated and/or approved wetland and associated buffer approved by the city, the approved wetland buffer will remain in effect. Redevelopment, previously disturbed areas (clearing limits), and/or additions outside of the existing footprint shall be subject to the previously approved buffer, however a buffer enhancement plan may be required in accordance with subsection D of this section if the wetland or buffer has become degraded or is currently not functioning or if the wetland and/or buffer may be negatively affected by proposed new development.

Nonconforming Uses in Buffers. Where a legally established, nonconforming use of the buffer existing (e.g., a road or structure that lies within the width of a wetland buffer), proposed actions in the buffer may be permitted as long as they do not increase the degree of non-conformity. This means no increase in the impacts to the wetland from activities in the buffer. For example, building an urban road is being proposed next to a Category II wetland. A one-hundred-fifty-foot buffer would be needed to protect function. If, however, an existing urban road is already present and only fifty feet from the edge of the Category II wetland, the additional one hundred feet of buffer may not be needed if the road is being widened. A vegetated buffer on the other side of the road would not help buffer the existing impacts to the wetland from the road. If the existing road is resurfaced or widened (e.g., to add a sidewalk) along the upland edge, without any further roadside development that would increase the degree of nonconformity, the additional buffer is not necessary. The associated increase in impervious surface from widening a road, however, may necessitate mitigation for impacts from stormwater. If, however, the proposal is to build a new development (e.g., shopping center or residential development) along the upland side of the road, the impacts to the wetland and its function may increase. This would increase the degree of nonconformity. The project proponent would need to provide the additional one hundred feet of buffer extending beyond the road or apply for buffer averaging.

Minor additions or alterations such as decks and small additions less than one hundred twenty square feet, interior remodels, or tenant improvements which have no impact on the wetland or wetland buffer are exempt from the buffer enhancement requirements.

An owner of a property containing wetlands may be permitted to transfer the density attributable to the wetland area to another nonwetland, nonsensitive portion of the same site or property, subject to the limitations of this section.

Up to one hundred percent of the density that could be achieved on the wetland and buffer portion of the site can be transferred to the non-wetland portion, subject to:

After careful consideration of the potential impacts and a determination that impacts are unavoidable, unavoidable impacts to wetlands not exempt under Section 17.52B.040 or meeting the criteria for a reasonable use exception in Section 17.52.025 shall be mitigated. Mitigation actions by an applicant shall occur in the following priority sequence:

Unless otherwise exempt, or an exception is granted by the city, alteration of wetlands and/or their buffers may be permitted by the city subject to the following criteria:

Proposals which include less preferred and/or compensatory mitigation shall demonstrate that:

Owners of property with Category I through IV wetlands may also provide a comparable alternative mitigation plan which will result in equal or better wetland quality.

Location and Timing of Mitigation.

Wetland Mitigation Ratios.

Mitigation Banking. The use of a mitigation bank may be approved for use as a compensation for unavoidable impacts to wetland when:

Where it is determined by the city that compensatory wetland mitigation is required or appropriate, a qualified wetland specialist shall prepare a preliminary and final mitigation plan using best available science in accordance with city requirements for city review. The mitigation plan shall include:

The applicant's qualified wetland specialist and the city must monitor installation of any construction to ensure mitigation is constructed or otherwise installed according to the approved mitigation plan requirements.

For those projects that are only required to provide buffer enhancement mitigation, an applicant may use the city's conceptual buffer mitigation plan as a basis to prepare a buffer enhancement plan. The final plan must be approved by the city's planning director prior to final approval of a proposed project.

A monitoring program shall be included as a part of the approved mitigation plan. To insure that the performance standards of the approved mitigation plan have been met, the mitigation and/or buffer enhancement site(s) shall be monitored for a minimum of five years. The monitoring period required by the city may be extended an additional two years if the wetland or buffer is not performing as expected by the mitigation or enhancement plan. The monitoring reports shall be submitted on August 1st of each year during the monitoring period. Monitoring reports shall follow the recommendations contained in the Department of Ecology's publication "Guidance on Wetland Mitigation in Washington State," Part Two.

An acceptable surety device is required to ensure the applicant's compliance with the terms of the mitigation agreement.

Long-Term Maintenance. To ensure the long term success of the wetland, the applicant or their heirs or successors shall be responsible for the long term maintenance of the wetland and its associated buffer. The wetland and buffer shall be kept clear of weeds, invasive plant material, lawn clippings, junk, debris, intrusions or the like.

Interpretation and Conflicts. Any questions regarding interpretation of this Chapter shall be resolved pursuant to the procedures set forth in Section 17.72.020 of this title.

Penalties and Enforcement. Compliance with this chapter and penalties for its violation shall be enforced pursuant to the procedures set forth in Title 18, Land Use Enforcement.

Appeals from Permit Decisions. Appeals from permit decisions shall be governed by the procedures set forth in Section 17.13.090, Appeals.