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(1) Designation.

(a) Wetlands are those areas designated based on the definitions, methods and standards set forth in the currently approved Federal Wetland Delineation Manual and supplements. Wetland delineations are valid for five years; after such date the city shall determine whether additional assessment is necessary. All areas within the city meeting the wetland designation criteria in the Delineation Manual and supplements are hereby designated critical areas and are subject to the provisions of this chapter.

(b) Wetlands shall be rated according to the Washington State Department of Ecology wetland rating system found in the Washington State Wetlands Rating System for Eastern Washington (Annotated Version), Washington State Department of Ecology Publication No. 04-06-018, June 2014; or as revised by Ecology. Other references for guidance and mitigations include Wetland Mitigation in Washington State – Parts 1 and 2, Washington Department of Ecology Publication No. 06-06-011a and b, March 2006, Wetlands in Washington State – Volume 1: A Synthesis of the Science, Washington State Department of Ecology Publication No. 05-06-006; and Wetlands in Washington State – Volume 2: Guidance for Protecting and Managing Wetlands, Washington State Department of Ecology Publication No. 05-06-008.

(2) Classification.

(a) Wetland rating classes shall be as follows:

(i) Category I Wetlands. Those wetlands scoring a “Category I” rating under the Washington State Department of Ecology (Ecology) Washington State Wetlands Rating System for Eastern Washington (Annotated Version), Publication No. 04-06-018, June 2014, as may be amended in the future (hereinafter referred to as the Ecology wetlands rating system);

(ii) Category II Wetlands. Those wetlands scoring a “Category II” rating under the Ecology wetlands rating system;

(iii) Category III Wetlands. Those wetlands scoring a “Category III” rating under the Ecology wetlands rating system; and

(iv) Category IV Wetlands. Those wetlands scoring a “Category IV” rating under the Ecology wetlands rating system.

(v) Irrigation-influenced Wetlands. Those wetlands that have resulted from Columbia Basin Project irrigation system development and irrigated agriculture and that are not intentionally created. These wetlands are to be classified per wetland rating classes Categories I through IV.

(vi) Intentionally Created Artificial Wetlands. Wetlands and former wetland areas not regulated are those intentionally created artificial wetlands, or irrigation-influenced wetlands that have dried up and are no longer functioning as a wetland due to changes in farming practices, or irrigation supply management and/or conservation measures.

(3) Site Assessment Requirements for Wetlands. In addition to the information described in ECMC 16.20.500(11), the wetlands site assessment report shall include the following information:

(a) Documentation of any fieldwork performed on the site, including field data sheets for delineations, function assessments, baseline hydrologic data, soils, and vegetative characteristics of the wetland including U.S. Army Corps delineation data sheets as applicable.

(b) A description of the methodologies used to conduct the wetland delineations, function assessments, or impact analyses including references.

(c) Identification and characterization of all critical areas, wetlands, water bodies, shorelines, floodplains, and buffers on or adjacent to the proposed project area. For areas off site of the project site, estimate conditions within 200 feet of the project boundaries using the best available information.

(d) For each wetland identified on site and within 200 feet of the project site provide: the wetland rating per wetland ratings; required buffers; hydrogeomorphic classification; wetland acreage based on a professional survey from the field delineation (acreages for on-site portion and entire wetland area including off-site portions); Cowardin classification of vegetation communities; habitat elements; soil conditions based on site assessment and/or soil survey information; and to the extent possible, hydrologic information such as location and condition of inlets/outlets (if they can be legally accessed), estimated water depths within the wetland, and estimated hydroperiod patterns based on visual cues (e.g., algal mats, drift lines, flood debris, etc.). Provide acreage estimates, classifications, and ratings based on entire wetland complexes, not only the portion present on the proposed project site.

(e) A description of the proposed actions including an estimation of acreages of impacts to wetlands and buffers based on the field delineation and survey and an analysis of site development alternatives including a no-development alternative.

(f) An assessment of the probable cumulative impacts to the wetlands and buffers resulting from the proposed development.

(g) A discussion of measures, including avoidance, minimization, and compensation, proposed to preserve existing wetlands and restore any wetlands that were degraded prior to the current proposed land use activity.

(h) A conservation strategy for habitat and native vegetation that addresses methods to protect and enhance on-site habitat and wetland functions.

(i) An evaluation of the functions of the wetland and adjacent buffer.

(j) A copy of the site plan sheet(s) for the project must be included with the written report and must include, at a minimum:

(i) Maps (to scale) depicting delineated and surveyed wetland and required buffers on site, including buffers for off-site critical areas that extend onto the project site; the development proposal; other critical areas; grading and clearing limits; areas of proposed impacts to wetlands and/or buffers (include square footage estimates);

(ii) A depiction of the proposed stormwater management facilities and outlets (to scale) for the development, including estimated areas of intrusion into the buffers of any critical areas. The written report shall contain a discussion of the potential impacts to the wetland(s) associated with anticipated hydroperiod alterations from the project.

(4) Alteration and Impacts of Wetlands.

(a) A regulated wetland or its required buffer can only be altered if the wetlands site assessment pursuant to subsection (3) of this section shows that the proposed alteration does not degrade the quantitative and qualitative functioning of the wetland, or any degradation can be adequately mitigated to protect the wetland function, and maintain no net loss of wetland functions and values as a result of the overall project. Any alteration approved pursuant to this section shall include mitigation necessary to mitigate the impacts of the proposed alteration on the wetland as described in subsection (5) of this section.

(b) The following activities are regulated if they occur in a regulated wetland or its buffer:

(i) The removal, excavation, grading, or dredging of soil, sand, gravel, minerals, organic matter, or material of any kind.

(ii) The dumping of, discharging of, or filling with any material.

(iii) The draining, flooding, or disturbing the water level or water table.

(iv) Pile driving.

(v) The placing of obstructions.

(vi) The construction, reconstruction, demolition, or expansion of any structure.

(vii) Activities that result in:

(A) A significant change in water temperature.

(B) A significant change of physical or chemical characteristics of the sources of water to the wetland.

(C) A significant change in the quantity, timing or duration of the water entering the wetland.

(D) The introduction of pollutants.

(c) Stormwater Discharge. Stormwater discharges to wetlands shall be controlled and treated to provide all known and reasonable methods of prevention, control, and treatment as mandated in the State Water Quality Standards, Chapter 173-201A WAC, as required by state law, and consistent with the Ecology Stormwater Manual for Eastern Washington. Changes in hydrology that negatively impact functions of a wetland shall not be permitted, except for intentionally created artificial wetlands, or irrigation-influenced wetlands that have been modified so that it no longer has wetland characteristics due to changes in farming practices or irrigation supply management and/or conservation measures. Potential changes may include, but not be limited to, flooding of plant communities resulting in changes in composition, flooding of nests, or associated drawdowns that dehydrate nests, particularly amphibian eggs.

(d) Exceptions to Mitigation Requirements. Requirements for mitigation do not apply under the following circumstances:

(i) When a wetland alteration is intended exclusively for the enhancement, rehabilitation or restoration of an existing regulated wetland and the proposal will not result in a loss of wetland function and value, subject to the following conditions:

(A) The enhancement or restoration project shall not be associated with a development activity; and

(B) An enhancement or restoration plan shall be submitted for site plan review. The restoration or enhancement plan must include the information required under subsection (3) of this section.

(C) When an artificial wetland is intentionally created from a nonwetland site, or a former irrigation influenced wetland was modified so that it no longer has wetland characteristics due to changes in farming practices or irrigation supply management and/or conservation measures.

(5) Development Standards.

(a) Lights shall be directed away from the wetland.

(b) Activities that generate noise shall be located away from the wetland, or noise impacts shall be minimized through design or insulation techniques.

(c) Toxic runoff from new impervious surface area shall be directed away from wetlands.

(d) Treated stormwater runoff may be allowed into wetland buffers. Channelized flow should be prevented.

(e) Use of pesticides, insecticides, and fertilizers within 150 feet of wetland boundary shall be limited and follow best management practices (BMPs).

(f) The outer edge of the wetland buffer shall be planted with dense native vegetation and/or fencing to limit pet and human disturbance.

(g) Measurement of Wetland Buffers. All buffers shall be measured from the wetland boundary as surveyed in the field. The width of the wetland buffer shall be determined according to the proposed land use (Table 16.20.520(5)(g)-1) and the wetland category (Table 16.20.520(5)(g)-2).

Table 16.20.520(5)(g)-1 – Land Use Intensity Table

Level of Impact from Proposed Change in Land Use

Types of Land Use Based on Common Zoning Designations

High

• Commercial

• Urban

• Industrial

• Institutional

• Retail sales

• Residential (more than one unit/acre)

• High-intensity recreation (golf courses, ball fields, etc.)

Moderate

• Residential (one unit/acre or less)

• Moderate-intensity open space (parks with biking, jogging, etc.)

• Paved driveways and gravel driveways serving three or more residences

• Paved trails

Low

• Low-intensity open space (hiking, bird-watching, preservation of natural resources, etc.)

• Timber management

• Gravel driveways serving two or fewer residences

• Unpaved trails

• Utility corridor without a maintenance road and little or no vegetation management.

Table 16.20.520(5)(g)-2 – Buffer Widths

Wetland Characteristics

Buffer Width by Impact of Proposed Land Use

Other Measures Recommended for Protection

Category IV Wetlands (for wetlands scoring less than 15 points or more for all functions)

Score for all three basic functions is less than 30 points

Low – 25 ft

Moderate – 40 ft

High – 50 ft

No recommendations at this time

Category III Wetlands (for wetlands scoring 16-18 points or more for all functions)

Moderate level of function for habitat (score for habitat 20 – 28 points)

Low – 75 ft

Moderate – 110 ft

High – 150 ft

No recommendations at this time

Not meeting above characteristic

Low – 40 ft

Moderate – 60 ft

High – 80 ft

No recommendations at this time

Category II Wetlands (for wetlands that score 19 – 21 points or more for all functions or having the “special characteristics” identified in the rating system)

High level of function for habitat (score for habitat 29 – 36 points)

Low – 100 ft

Moderate – 150 ft

High – 200 ft

Maintain connections to other habitat areas

Moderate level of function for habitat (score for habitat 20 – 28 points)

Low – 75 ft

Moderate – 110 ft

High – 150 ft

No recommendations at this time

High level of function for water quality improvement and low for habitat (score for water quality 24 – 32 points; habitat less than 20 points)

Low – 50 ft

Moderate – 75 ft

High – 100 ft

No additional surface discharges of untreated runoff

Riparian forest

Buffer width to be based on score for habitat functions or water quality functions

Riparian forest wetlands need to be protected at a watershed or subbasin scale

Other protection based on needs to protect habitat and/or water quality functions

Not meeting above characteristic

Low – 50 ft

Moderate – 75 ft

High – 100 ft

No recommendations at this time

Category I Wetlands (for wetlands that score 22 points or more for all functions or having the “special characteristics” identified in the rating system)

Natural Heritage Wetlands

Low – 125 ft

Moderate – 190 ft

High – 250 ft

No additional surface discharges to wetland or its tributaries

No septic systems within 300 ft of wetland

Restore degraded parts of buffer

High level of function for habitat (score for habitat 29 – 36 points)

Low – 100 ft

Moderate – 150 ft

High – 200 ft

Restore degraded parts of buffer

Maintain connections to other habitat areas

Moderate level of function for habitat (score for habitat 20 – 28 points)

Low – 75 ft

Moderate – 110 ft

High – 150 ft

No recommendations at this time

High level of function for water quality improvement (24 – 32 points) and low for habitat (less than 20 points)

Low – 50 ft

Moderate – 75 ft

High – 100 ft

No additional surface discharges of untreated runoff

Not meeting above characteristics

Low – 50 ft

Moderate – 75 ft

High – 100 ft

No recommendations at this time

(h) Wetland buffer zones shall be retained in their natural condition. Wetland buffers shall not be mowed. Where buffer disturbances are unavoidable during adjacent construction, revegetation with native plant materials will be required.

(i) Standard buffer widths shall be measured on the horizontal from the wetland boundary as surveyed in the field. Standard buffer widths may be modified by the review authority for a development proposal by averaging buffer widths based on a report submitted by the applicant and prepared by a qualified professional approved by the shoreline administrator (e.g., wetland biologist), and shall only be allowed where the applicant demonstrates all of the following:

(i) Averaging is necessary to avoid an extraordinary hardship to the applicant caused by circumstances peculiar to the property;

(ii) The designated wetland contains variations in sensitivity due to existing physical characteristics that affect its habitat functions, such as a wetland with a forested component adjacent to a degraded emergent component or a “dual-rated” wetland with a Category I area adjacent to a lower-rated area;

(iii) The width averaging will not adversely impact the designated wetland’s functional value;

(iv) The total area contained within the buffer after averaging is no less than that contained within the standard buffer prior to averaging;

(v) The buffer at its narrowest point is never less than three-quarters of the required width.

(j) Mitigation ratios shall be used when impacts to wetlands cannot be avoided. The mitigation ratios by wetland type are an area replacement ratio of:

Table 16.20.520(5)(j) – Mitigation Ratios for Eastern Washington

Category and Type of Wetland Impacts

Reestablishment or Creation

Rehabilitation Only1

Reestablishment or Creation (R/C) and Rehabilitation (RH)1

Reestablishment or Creation (R/C) and Enhancement (E)1

Enhancement Only1

All Category IV

1.5:1

3:1

1:1 R/C and 1:1 RH

1:1 R/C and 2:1 E

6:1

All Category III

2:1

4:1

1:1 R/C and 2:1 RH

1:1 R/C and 4:1 E

8:1

All other Category II

3:1

6:1

1:1 R/C and 4:1 RH

1:1 R/C and 8:1 E

12:1

Category I based on score for functions

4:1

8:1

1:1 R/C and 6:1 RH

1:1 R/C and 12:1 E

16:1

Category I Natural Heritage site

Not considered possible2

6:1 Rehabilitation of a Natural Heritage site

R/C Not considered possible2

R/C Not considered possible2

Case-by-case

1These ratios are based on the assumption that the rehabilitation or enhancement actions implemented represent the average degree of improvement possible for the site. Proposals to implement more effective rehabilitation or enhancement actions may result in a lower ratio, while less effective actions may result in a higher ratio. The distinction between rehabilitation and enhancement is not clear-cut. Instead, rehabilitation and enhancement actions span a continuum. Proposals that fall within the gray area between rehabilitation and enhancement will result in a ratio that lies between the ratios for rehabilitation and the ratios for enhancement.

2Natural Heritage sites, alkali wetland, and bogs are considered irreplaceable wetlands because they perform some functions that cannot be replaced through compensatory mitigation. Impacts to such wetlands would therefore result in a net loss of some functions no matter what kind of compensation is proposed.

Reference:

Washington State Department of Ecology, U.S. Army Corps of Engineers Seattle District, and U.S. Environmental Protection Agency Region 10. March 2006. Wetland Mitigation in Washington State – Part 1: Agency Policies and Guidance (Version 1). Washington State Department of Ecology Publication No. 06-06-011a. Olympia, WA.

(k) Water-dependent uses, as defined in this chapter, may be located within a wetland or wetland buffer when the applicant or property owner can demonstrate compliance with ECMC 16.20.510, General performance standards.

(i) Developments authorized within a wetland buffer shall comply with the following minimum standards:

(A) Designated wetlands and their associated buffers shall be delineated and disclosed on final plats, maps, documents, etc., as critical area tracts, nonbuildable lots, buffer areas or common areas. Ownership and control may be designated as an easement or covenant encumbering the property.

(B) All lots within a major subdivision, short plat or binding site plan shall have the outer edge of all required buffers clearly marked on site with permanent buffer edge markers. Buffer markers may be either buffer signs or steel posts painted with a standard color and label, as approved by the shoreline administrator. The markers shall be field verified by the surveyor or biologist of record prior to final plat approval. Each lot shall contain a minimum of three buffer area markers located at the landward edge of the buffer perimeter for each habitat type; one located at each side property line and one midway between side property lines. Covenants for the subdivision shall incorporate a requirement stating that buffer area markers shall not be removed, or relocated, except as may be approved by the shoreline administrator.

(l) The following activities are allowed to occur in wetlands and wetland buffer zones subject to conditioning with appropriate best management practices to minimize impacts on the functions and values of wetlands:

(i) Conservation and restoration activities. Conservation or restoration activities aimed at protecting the soil, water, vegetation, or wildlife.

(ii) Passive recreation. Passive recreation facilities designed and in accordance with an approved critical area report, including:

(A) Walkways and trails, provided that those pathways are limited to minor crossings having no adverse impact on water quality. They should be generally parallel to the perimeter of the wetland, located only in the outer 25 percent of the wetland buffer area, and located to avoid removal of significant trees. They should be limited to pervious surfaces no more than five feet in width for pedestrian use only. Raised boardwalks utilizing nontreated pilings may be acceptable.

(B) Wildlife-viewing structures.

(iii) Educational and scientific research activities.

(iv) Normal and routine maintenance and repair of any existing public or private facilities within an existing right-of-way; provided, that the maintenance or repair does not increase the footprint or use of the facility or right-of-way.

(v) The harvesting of wild crops in a manner that is not injurious to natural reproduction of such crops and provided the harvesting does not require tilling of soil, planting of crops, chemical applications, or alteration of the wetland by changing existing topography, water conditions, or water sources.

(vi) Drilling for utilities/utility corridors under a buffer, with entrance/exit portals located completely outside of the wetland buffer boundary; provided, that the drilling does not interrupt the ground water connection to the wetland or percolation of surface water down through the soil column. Specific studies by a hydrologist are necessary to determine whether the ground water connection to the wetland or percolation of surface water down through the soil column is disturbed.

(vii) Enhancement of a wetland buffer through the removal of nonnative invasive plant species. Removal of invasive plant species shall be restricted to hand removal. All removed plant material shall be taken away from the site and appropriately disposed of. Plants that appear on the Washington State Noxious Weed Control Board list of noxious weeds must be handled and disposed of according to a noxious weed control plan appropriate to that species. Revegetation with appropriate native species at natural densities is allowed in conjunction with removal of invasive plant species.

(m) Stormwater management facilities shall be allowed within the outer 25 percent of a wetland buffer around Category III or IV wetlands; provided, that no other location is feasible and that the location of such facilities will not degrade the functions of the wetland or its buffer. All projects shall comply with the applicable federal, state and local regulations regarding the species.

(n) As a condition of any permit or authorization pursuant to these regulations, the shoreline administrator may require temporary or permanent signs and/or fencing along the perimeter of a wetland or buffer in order to protect the functions and values of the wetland, or to minimize future impacts or encroachment upon the wetland or buffer.

(o) Wetland alteration proposals shall be approved only if no alternative is available. If alteration is unavoidable, all adverse impacts shall be mitigated as set forth in an approved critical areas report and mitigation plan.

(p) When feasible, mitigation shall be on site and sufficient to maintain the functions and values of the wetland and buffer areas. If on-site mitigation is not feasible, then the applicant shall demonstrate that the mitigation site is the nearest that can reasonably achieve the goals of mitigation with a high likelihood of success.

(q) As determined through the site-specific study, mitigation measures shall be implemented that maintain the functions and values found in the particular wetland.

(r) As determined through the site-specific study, appropriate mitigation, management and monitoring plan(s) shall be developed and implemented, with any necessary surety to ensure compliance with such plan(s) being provided as described hereinabove.

(s) A legally established use or structure established prior to the effective date of the ordinance codified in this chapter which does not conform to standards set forth herein is allowed to continue and be reasonably maintained; provided, that such activity or structure shall not be expanded or enlarged in any manner that increases the extent of its nonconformity.

(6) Wetland Management and Mitigation Plan.

(a) Compensatory Mitigation Plan. Where mitigation is required pursuant to ECMC 16.20.510, the applicant shall prepare a mitigation plan. The mitigation plan shall follow the general requirements described hereinbelow and Wetland Mitigation in Washington State – Part 2: Developing Mitigation Plans (Version 1), Washington Department of Ecology (Publication No. 06-06-011b, March 2006 or as revised), and Selecting Wetland Mitigation Sites Using a Watershed Approach (Eastern Washington) (Publication No. 10-06-07, November 2010, or as revised). The following items at a minimum are required as part of a mitigation plan:

(i) Description of project or activity, including a detailed narrative describing the project or activity, its relationship to the wetland and its potential impact to the wetland; and

(ii) Any proposed mitigation, including a discussion of how the project has been designed to avoid and minimize adverse impacts to wetlands, as well as the necessary monitoring and contingency actions for the continued maintenance of the wetland and its associated buffer;

(iii) A report which includes, but is not limited to:

(A) Location maps.

(B) A site map prepared at a scale no smaller than one inch equals 200 feet indicating the boundaries of the identified wetlands; the width and length of all existing and proposed structures, utilities, roads, easements; wastewater and stormwater management facilities; adjacent land uses, zoning districts, and comprehensive plan designations;

(C) A description of the vegetation in the wetland, on the overall project site, and adjacent to the site. A description of the existing wetland and buffer areas proposed to be impacted;

(D) A discussion of any federal, state, or local wetland-related permits required for the project;

(E) A discussion of the following mitigation alternatives as they relate to the proposal:

1. Avoiding the impact altogether by not taking a certain action or parts of an action;

2. Minimizing impacts by limiting the degree or magnitude of the action and its implementation, by using appropriate technology, or by taking affirmative steps to avoid or reduce impacts;

3. Rectifying the impact by repairing, rehabilitating, or restoring the affected environment;

4. Compensating for functions affected by the proposed project, with the intention to achieve functional equivalency or improvement of functions;

(iv) Include a description of the compensatory mitigation site, including location and rationale for selection. Describe how preferred order of wetlands mitigation was followed: (A) restoration (including reestablishment and rehabilitation), (B) creation (establishment), (C) enhancement in combination with restoration or creation, and (D) preservation of high-quality, at-risk wetlands. Include an assessment of existing conditions and estimate future conditions if actions are not undertaken. Describe the proposed actions for compensating wetland and upland areas affected by the project. Include the overall goals of the proposed mitigation, including targeted functions. Describe the proposed mitigation construction activities and timing of activities, along with a detailed discussion of ongoing management and monitoring practices which will protect the wetland after the project site has been fully developed, including proposed monitoring, contingency, maintenance and surety programs; and

(v) Proposed mitigation ratios, including a discussion of functions and values of and the variety of habitats provided by the proposed replacement wetland. To more fully protect functions and values, and as an alternative to the mitigation ratios found in the joint guidance “Wetland Mitigation in Washington State Parts I and II” (Ecology Publication No. 06-06-011a-b, Olympia, WA, March 2006), the shoreline administrator may allow mitigation based on the “credit/debit” method developed by the Department of Ecology in “Calculating Credits and Debits for Compensatory Mitigation in Wetlands of Eastern Washington: Final Report” (Ecology Publication No. 11-06-015, August 2012, or as revised). (Ord. 484 § 2, 2014)