Chapter 16.17
WETLANDS PROTECTION

Sections:

16.17.010    Purpose.

16.17.020    Applicability.

16.17.030    Mapping.

16.17.040    Wetlands rating.

16.17.050    Development standards.

16.17.060    Wetland study.

16.17.070    Mitigation requirements.

16.17.080    Mitigation plans.

16.17.090    Performance standards—Subdivision.

16.17.110    Nonconforming activities.

16.17.120    Reasonable use exception.

16.17.130    Modification of wetland permits.

16.17.140    Amendments.

16.17.010 Purpose.

The purpose of this chapter is to regulate the use of land on and around wetlands; to protect wetlands from new nearby activities; to comply with the Washington State Growth Management Act, Chapter 36.70A RCW, and other city and state regulations and policies; and to protect the public health, safety and welfare by preventing the adverse environmental impacts of development. (Ord. 2232 § 5 (Exh. A), 2009).

16.17.020 Applicability.

Wetlands and wetland buffers are those areas within the city and its jurisdiction which satisfy the definitions established in this title. (Ord. 2232 § 5 (Exh. A), 2009).

16.17.030 Mapping.

A.    The approximate location and extent of wetlands in the city is displayed on the map titled Wetlands and Hydric Soils, 2001. This inventory is general and not designed to support permit applications, and does not establish jurisdictional boundaries. Furthermore, as site conditions change (due to natural and human processes), wetland areas and characteristics may change as well.

B.    The exact location of the wetland boundary shall be determined by the applicant through the performance of a field investigation applying the wetland definition provided in this title. (Ord. 2232 § 5 (Exh. A), 2009).

16.17.040 Wetlands rating.

A.    Wetlands shall be rated according to the Washington State Department of Ecology wetland rating system found in the Washington State Wetland Rating System for Western Washington (Department of Ecology Publication No. 14-06-029, October 2014) or as amended hereafter. This document contains the definitions and methods for determining if the criteria below are met.

Wetlands buffer widths, replacement ratios and avoidance criteria shall be based on this rating system. Wetland rating categories shall be applied as the regulated wetland exists on the date of adoption of the rating system by the city, as the regulated wetland may naturally change in accordance with permitted activities. Wetland rating categories shall not be altered to recognize illegal modifications.

1.    Washington State Four-Tier Wetlands Rating System.

a.    Category I Criteria.

i.    Relatively undisturbed estuarine wetlands larger than one acre.

ii.    Wetlands that are identified by scientists of the Washington Natural Heritage Program/DNR as high quality wetlands.

iii.    All bogs.

iv.    Mature and old growth forested wetlands larger than one acre.

v.    Wetlands in coastal lagoons.

vi.    Wetlands that perform functions at high levels scoring twenty-three points or more on the questions related to functions.

b.    Category I wetlands are those that:

i.    Represent a unique or rare wetland type; or

ii.    Are more sensitive to disturbance than most wetlands; or

iii.    Are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or

iv.    Provide a high level of functions.

c.    Category II Criteria.

i.    Estuarine wetlands smaller than one acre, or disturbed estuarine wetlands larger than one acre;

ii.    Wetlands judged to perform most functions relatively well (scoring twenty to twenty-two points on the questions related to functions), or performed one group of functions very well and the other two moderately well.

d.    Category III Criteria. Wetlands with a moderate level of functions (scores between sixteen and nineteen points) and often can be adequately replaced with a well-planned mitigation project.

e.    Category IV Criteria. Category IV wetlands have the lowest levels of functions (scores less than sixteen points) and are often heavily disturbed.

B.    Very Small Wetland Standards. Very small wetlands of four thousand square feet or less may or may not provide wetland functions that require protection. The following standards apply to regulating wetlands of four thousand square feet or less:

1.    For a wetland less than one thousand square feet to be declared exempt, it must be shown by the applicant that the following criteria have been met:

a.    They are not associated with a riparian corridor; and

b.    They are not part of a wetland mosaic; and

c.    They do not contain habitat identified as essential for local populations of priority species identified by Washington Department of Fish and Wildlife.

2.    The requirement to avoid impacts may be dropped for Category III and IV wetlands between one thousand and four thousand square feet that meet all of the following criteria:

a.    Wetland is not associated with a riparian corridor; and

b.    Wetland is not part of a wetland mosaic; and

c.    Wetland does not score five points or greater for habitat in the 2014 Western Washington Rating System; and

d.    Wetland does not contain habitat identified as essential for local populations of priority species identified by Washington Department of Fish and Wildlife.

3.    Impacts allowed under this provision to these wetlands will be fully mitigated as required in mitigation sections CMC 16.17.070 and 16.17.080.

C.    Date of Wetland Rating. Wetland rating categories shall be applied as the wetland exists on the date of adoption of the rating system by the city, as the wetland naturally changes thereafter, or as the wetland changes in accordance with permitted activities. Wetland rating categories shall not change due to illegal modifications. (Ord. 2396 § 7, 2017: Ord. 2232 § 5 (Exh. A), 2009).

16.17.050 Development standards.

A.    Activities may only be permitted in a wetland or wetland buffer if the applicant can show that the proposed activity will not degrade the functions and functional performance of the wetland and other critical areas.

B.    Activities and uses shall be prohibited in wetlands and wetland buffers, except as provided for in this title.

C.    Category I Wetlands. Activities and uses shall be prohibited from Category I, except as provided for in the public agency and utility exception, reasonable use exception, and variance sections of this title.

D.    Category II and III Wetlands. With respect to activities proposed in Category II and III wetlands, the following standard shall apply:

1.    Water-dependent activities as provided for under the city’s shoreline master program may be allowed where there are no feasible alternatives that would have a less adverse impact on the wetland, its buffers and other critical areas.

2.    Where nonwater-dependent activities are proposed, it shall be presumed that alternative locations are available, and activities and uses shall be prohibited, unless the applicant demonstrates that:

a.    The basic project purpose cannot reasonably be accomplished and successfully avoid or result in less adverse impact on a wetland on another site or sites in the general region;

b.    All alternative designs of the project as proposed that would avoid or result in less of an adverse impact on a wetland or its buffer, such as a reduction in the size, scope, configuration, or density of the project, are not feasible; and

c.    Full compensation for the acreage and loss of functions will be provided under the terms established under CMC 16.17.070(G), Mitigation Requirements.

E.    Category IV Wetlands. Activities and uses that result in unavoidable and necessary impacts may be permitted in Category IV wetlands and associated buffers in accordance with an approved wetland report and mitigation plan, and only if the proposed activity is the only reasonable alternative that will accomplish the applicant’s objectives. Full compensation for the acreage and loss of functions will be provided under the terms established under CMC 16.17.070(G), Mitigation Ratios.

F.    Buffers. Wetland buffer zones shall be required for all regulated activities adjacent to regulated wetlands. Any wetland created, restored or enhanced as compensation for approved wetland alterations shall also include a buffer equivalent to or greater than that required for the category of wetland to be replaced. Buffer widths presume the existence of relatively intact native vegetation within the buffer zone that is adequate to protect the wetland values and functions. If the vegetation is inadequate, then the buffer width may be increased or additional plants added to maintain the width. The width of the wetland buffer shall be based on the wetland category according to the following table:

Wetland Category: Scoring system uses the Washington State Wetland Rating System for Western Washington	Low Intensity Land Uses: Forestry (not including roads), utility corridor (without associated road), passive recreation not otherwise allowed	Moderate Intensity Land Uses: Residential development with net density of 1 unit/acre or less dense; active recreation (sport courts, golf courses); paved trails or logging roads; utility corridors with associated access and maintenance roads	High Intensity Land Uses: Commercial, industrial, or institutional development; residential net densities greater than 1 unit/acre
Category I
Natural heritage wetlands	125 feet	190 feet 300 feet for septic systems	250 feet 300 feet for septic systems
Bogs	125 feet	190 feet	250 feet
Habitat score: 8—9 points	150 feet	225 feet	300 feet
Habitat score: 5—7 points	75 feet	110 feet	150 feet
Water quality score: 8—9 points and habitat score: 3—4 points	50 feet	75 feet	100 feet
Not meeting any of the above characteristics	50 feet	75 feet	100 feet
Category II
Habitat score: 8—9 points	150 feet	225 feet	300 feet
Habitat score: 5—7 points	75 feet	110 feet	150 feet
Water quality score: 8—9 points and habitat score: 3—4 points	50 feet	75 feet	100 feet
Not meeting above characteristics	50 feet	75 feet	100 feet
Category III
Habitat function score: 5—7 points	75 feet	110 feet	150 feet
Habitat score 3—4 points	40 feet	60 feet	80 feet
Category IV
Score 9—15 points for all functions	25 feet	40 feet	50 feet

1.    Measurement of Wetland Buffers. All buffers shall be measured horizontally from a perpendicular line established at the wetland edge as surveyed in the field. The width of the wetland buffer shall be determined according to the wetland category. 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. The following table provides examples of measures that can minimize impacts to wetlands from proposed change in land use:

Examples of Disturbance	Activities and Uses that Cause Disturbances		Examples of Measures to Minimize Impacts
Lights	• Parking lots • Warehouse • Manufacturing • Residential		• Direct lights away from wetland
Noise	• Manufacturing • Residential		• Locate 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 while ensuring wetland is not dewatered • Establish covenants limiting use of pesticides within 150 feet of wetland • Apply integrated pest management
Stormwater runoff	• Parking lots • Roads • Manufacturing • Residential areas • Commercial • Landscaping		• Retrofit stormwater detention and treatment for roads and existing adjacent development • Prevent channelized flow from lawns that directly enters the buffer
Change in water regime	• Impermeable surfaces • Lawns • Tilling		• Infiltrate or treat, detain, and disperse into buffer new runoff from impervious surfaces and new lawns
Pets and human disturbance	• Residential areas		• Use privacy fencing; plant dense vegetation to delineate buffer edge and to discourage disturbance using vegetation appropriate for the ecoregion; place wetland and its buffer in a separate tract
Dust	• Tilled fields		• Use best management practices to control dust

*These examples are not necessarily adequate for minimizing toxic runoff if threatened or endangered species are present at the site.

2.    Increased Buffers. The director may require additional buffer width around a wetland on a case-by-case basis when it can be demonstrated that the increase is necessary to:

a.    Protect the function and value of the wetland; or

b.    Protect habitat for federally or state listed fish and wildlife species, or federally listed plant species.

c.    An additional buffer width may be increased in accordance with the recommendations of an experienced, qualified professional wetland scientist, and the best available science.

3.    Buffer Width Averaging Standards. Buffer averaging to improve wetland protection may be permitted when all of the following are met:

a.    The wetland has significant differences in 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; and

b.    The buffer is increased adjacent to the higher functioning area of habitat or more sensitive portion of the wetland and decreased adjacent to the lower functioning or less sensitive portion; and

c.    The total buffer area after averaging is equal to the area required with averaging; and

d.    The buffer at its narrowest point is never less than three-quarters of the standard width.

e.    Buffer width averaging standards may not be used in conjunction with buffer reduction standards.

Averaging to allow reasonable use of a parcel may be permitted when all of the following are met:

a.    There are no feasible alternatives to the site design that could be accomplished without buffer averaging; and

b.    The averaged buffer will not result in degradation of the wetland’s functions and values as demonstrated by a report from a qualified wetland professional; and

c.    The total buffer area after averaging is equal to the area required without averaging; and

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

4.    Buffer Width Reduction Standards. The director may reduce the standard wetland buffer zone widths on a case-by-case basis where it can be demonstrated by a qualified professional wetland scientist that:

a.    The proposal will not reduce the function and value of the wetland;

b.    The proposal will not reduce the function of a habitat for federally or state listed fish and wildlife species, or federally listed plant species; or

c.    A buffer enhancement plan using native vegetation may be required to maintain the functional attributes of the buffer. An enhanced buffer shall not result in greater than a twenty-five percent reduction in the buffer width or a reduced buffer less than fifty feet, whichever is larger.

d.    Buffer width reduction standards may not be used in conjunction with buffer averaging standards.

5.    Buffer Maintenance. Except as otherwise specified or allowed in accordance with this title, wetland buffers shall be retained in an undisturbed or enhanced condition. Where buffer disturbance has occurred during construction, revegetation with native vegetation will be required.

6.    Permitted Buffer Uses. The following activities shall be allowed within a wetland or wetland buffer provided they are conducted using best management practices:

a.    Activities on areas lying fallow as part of a conventional rotational cycle are part of an ongoing operation. Activities which bring an area into agricultural use are not part of an ongoing operation. An operation ceases to be ongoing when the area on which it was conducted has been converted to another use;

b.    Conservation and Restoration Activities. Conservation or restoration activities aimed at protecting the soil, water, vegetation, or wildlife;

c.    Passive Recreation. Low-impact uses and activities which are consistent with the purpose and function of the wetland buffer and do not detract from its integrity may be permitted within the buffer depending on the sensitivity of the wetland. Trails may be permitted at the discretion of the director if they are limited to permeable surfaces no more than five feet wide and located within the outer twenty-five percent of the buffer. Trails must be designed to avoid removal of significant trees. Trails shall not be permitted in the wetlands themselves except for minor crossings that minimize impact;

d.    Stormwater Management Facilities. Stormwater management facilities, limited to stormwater dispersion outfalls, storm ponds and bioswales, may be allowed within the outer seventy-five percent of the buffer of Category III or IV wetlands only; provided, that no other location is feasible and the location of such facilities will not degrade the functions or values of the wetland;

e.    Navigation aids and boundary markers;

f.    Boat mooring buoys;

g.    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, or alteration of the wetland by changing existing topography, water conditions or water sources; and

h.    The following uses are allowed within wetlands and/or wetland buffers; provided, that written notice at least ten days prior to the commencement of such work has been given to the director; and provided, that wetland impacts are minimized and that disturbed areas are immediately restored:

i.    Normal maintenance, repair, or operation of existing serviceable structures, facilities, or improved areas. Maintenance and repair does not include any modification that changes the character, scope, or size of the original structure, facility, or improved area and does not include the construction of a maintenance road; and

ii.    Minor modification of existing serviceable structures within a buffer zone where modification does not adversely impact wetland functions.

7.    Regulated Buffer Uses. An approval from the director shall be obtained prior to undertaking the following in a regulated wetland or its buffer unless authorized:

a.    The removal, excavation, grading, or dredging of soil, sand, gravel, minerals, organic matter, or material of any kind;

b.    The dumping, discharging, or filling with any material;

c.    The draining, flooding, or disturbing of the water level or water table;

d.    The driving of pilings;

e.    The placing of obstructions;

f.    The construction, reconstruction, demolition, or expansion of any structure;

g.    The destruction or alteration of wetlands vegetation through clearing, harvesting, intentional burning, or planting of vegetation within a regulated wetland or its buffer that would alter the character of a regulated wetland; provided, that these activities are not part of a forest practice governed under Chapter 76.09 RCW and its rules; or

h.    Activities adjacent to a regulated wetland that result in a significant adverse impact to the functions and values provided by the wetland or its buffer;

i.    For Category I wetlands, an applicant must demonstrate that denial of the permit would impose an extraordinary hardship on the part of the applicant brought about by circumstances peculiar to the subject property;

j.    For Category II and III wetlands, the following provision shall apply:

Where nonwater-dependent activities are proposed, it shall be presumed that adverse impacts are avoidable. This presumption may be rebutted upon a demonstration that the basic project purpose cannot reasonably be accomplished utilizing one or more other sites in the general region that would avoid, or result in less, adverse impact on a regulated wetland; and a reduction in the size, scope, configuration, or density of the project as proposed and all alternative designs of the project as proposed that would avoid, or result in less, adverse impact on a regulated wetland or its buffer will not accomplish the basic purpose of the project; and in cases where the applicant has rejected alternatives to the project as proposed due to constraints such as zoning, deficiencies of infrastructure, or parcel size, the applicant has made reasonable attempt to remove or accommodate such constraints;

k.    With respect to Category IV wetlands, unavoidable and necessary impacts can be demonstrated where the proposed activity is the only reasonable alternative which will accomplish the applicant’s objectives.

8.    Signs and Fencing. As a condition of any permit or authorization issued pursuant to this chapter, the director may require the applicant to install temporary or permanent signs along the boundary of a wetland or buffer.

a.    Buffer Marking. Buffer markers may be required around the outer perimeter of the wetland or buffer and the limits of the areas to be disturbed pursuant to an approved permit or authorization. Markers shall be placed in the field in such a way as to ensure that no unauthorized intrusion will occur, and inspected by the director prior to the commencement of permitted activities. This marking shall be maintained throughout construction, and shall not be removed until permanent signs, if required, are in place.

b.    Permanent Signs. Permanent signs shall be made of a metal face and attached to a metal post, or another material of equal durability. Signs must be posted at an interval of one per lot or every fifty feet, whichever is less, and must be maintained by the property owner in perpetuity. The sign shall be worded as follows or with alternative language approved by the director:

Protected Wetland Area

Do Not Disturb

Contact City of Centralia (360) 330-7662

Regarding Uses and Restriction

c.    Fencing. The director shall determine if fencing is necessary to protect the functions and values of the critical area. If found to be necessary, the director shall require the applicant to install a permanent fence at the edge of the wetland buffer. The applicant will be required to install a permanent fence around the wetland or buffer when domestic grazing animals are present or may be introduced on site. The fencing shall be designed so as to not interfere with species migration and constructed in a manner that minimizes impacts to the wetland and associated habitat. Fencing will usually be black vinyl coated chain link to blend in with the native landscaping unless approved by the director. In no case shall the following types of fencing be allowed: uncoated chain link, masonry, block, wood, or other sight obscuring material. (Ord. 2396 § 8, 2017: Ord. 2232 § 5 (Exh. A), 2009).

16.17.060 Wetland study.

A.    Critical area reports for wetlands must meet the requirements of this section.

B.    The wetland study shall be prepared by a qualified professional who is a wetland biologist with experience preparing wetland reports.

C.    A wetland study shall contain the following site- and proposal-related information at a minimum:

1.    A written assessment and accompanying maps of the wetlands and buffers within two hundred feet of the project area, including the following information at a minimum:

a.    Wetland delineation and required buffers;

b.    Existing wetland acreage;

c.    Wetland category; vegetative, faunal, and hydrologic characteristics;

d.    Soil and substrate conditions;

e.    Topographic elevations, at two-foot contours;

f.    All shoreline areas, water features, floodplains, other critical areas, and related buffers within two hundred feet of the project area;

2.    A site plan for the proposed activity overlaid on an aerial photograph at a scale no smaller than one inch equals four hundred feet showing the location, width, depth and length of all existing and proposed structures, roads, sewage treatment, and installations within the wetland and its buffer;

3.    The exact sites and specifications for all regulated activities;

4.    A discussion of measures, including avoidance, minimization and mitigation, proposed to preserve existing wetlands and restore any wetlands that were degraded prior to the current proposed land use activity;

5.    The purposes of the project and an explanation why the proposed activity cannot be located at other sites including an explanation of how the proposed activity is dependent upon wetlands or water-related resources; except that proposals to alter prior converted cropland need not provide this explanation;

6.    Proposed mitigation, if needed, including a written assessment and accompanying maps of the mitigation area, including the following information at a minimum:

a.    Existing and proposed wetland acreage;

b.    Vegetative, faunal, and hydrologic conditions;

c.    Relationship within watershed and to existing waterbodies;

d.    Soil and substrate conditions, topographic elevations;

e.    Existing and proposed adjacent site conditions;

f.    Required wetland buffers; and

g.    Property ownership;

7.    A discussion of ongoing management practices that will protect wetlands after the project site has been developed, including proposed monitoring and maintenance programs.

a.    The director may require additional information including, but not limited to, an assessment of wetland functional characteristics, including a discussion of the methodology used; documentation of the ecological, aesthetic, economic, or other values of a wetland; a study of flood, erosion, or other hazards at the site and the effect of any protective measures that might be taken to reduce such hazards; and any other information deemed necessary to verify compliance with the provisions of this chapter or to evaluate the proposed use in terms of the purposes of this chapter.

b.    When appropriate, the director may also require the wetland analysis to include an evaluation by the Department of Ecology or an independent qualified expert regarding the applicant’s analysis and the effectiveness of any proposed mitigating measures or programs, and to include any recommendations as appropriate. (Ord. 2232 § 5 (Exh. A), 2009).

16.17.070 Mitigation requirements.

A.    Compensating for Wetland Impacts. As a condition of any permit allowing alteration of wetland and/or wetland buffers, or as an enforcement action pursuant to CMC 16.16.140, the city shall require that the applicant demonstrate that wetland impact avoidance is not possible and engage in the restoration, creation or enhancement of wetlands and their buffers in order to offset the impacts resulting from the applicant’s or violator’s actions. Mitigation for alterations to wetlands shall achieve equivalent or greater biologic functions. Mitigation plans shall be consistent with the Washington State Department of Ecology Wetland Mitigation in Washington State: Part 2—Developing Mitigation Plans, March 2006, as revised. The applicant shall develop a plan that provides for land acquisition, construction, maintenance and monitoring of replacement wetlands that recreate as nearly as possible the original wetlands in terms of acreage, function, geographic location and setting, and that are larger than the original wetlands. Compensatory mitigation shall be completed prior to wetland destruction, where possible. Mitigation shall result in no net loss of wetlands function and acreage and seeks a net resource gain in wetlands over present conditions with the exception of enforcement actions.

B.    Mitigation shall be required in the following order of preference:

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.    Reducing or eliminating the impact over time by preservation and maintenance operations.

5.    Compensating for the impact by replacing, enhancing, or providing substitute resources or environments. This type of mitigation can include an in-lieu of program established by the city.

C.    Mitigation for Lost or Affected Functions. Compensatory mitigation actions shall address functions affected by the alteration to achieve functional equivalency or improvement and shall provide similar wetland functions as those lost, except when:

1.    The lost wetland provides minimal functions as determined by a site-specific function assessment, and the proposed compensatory mitigation action(s) will provide equal or greater functions or will provide functions shown to be limiting within a watershed through a formal Washington State watershed assessment plan or protocol; or

2.    Out-of-kind replacement will best meet formally identified watershed goals, such as replacement of historically diminished wetland types.

D.    Mitigation actions that require compensation by replacing, enhancing, or substitution shall occur in the following order of preference:

1.    Restoring wetlands on upland sites that were formerly wetlands.

2.    Creating wetlands on disturbed upland sites such as those with vegetative cover consisting primarily of nonnative introduced species. This should only be attempted when there is a consistent source of hydrology and it can be shown that the surface and subsurface hydrologic regime is conducive for the wetland community that is being designed.

3.    Enhancing significantly degraded wetlands in combination with restoration or creation. Such enhancement should be part of a mitigation package that includes replacing the impacted area meeting appropriate ratio requirements.

E.    Type and Location of Mitigation. Unless it is demonstrated that a higher level of ecological functioning would result from an alternate approach, such as a mitigation bank located within WRIA 23 Upper Chehalis Watershed or the city of Centralia-sponsored fee-in-lieu program compensatory mitigation for ecological functions shall be either in-kind and on-site, or in-kind and within the same stream reach, subbasin, or drift cell. Mitigation actions shall be conducted within the same sub-drainage basin and on the site as the alteration except when all of the following apply:

1.    There are no reasonable on-site or in-subdrainage basin opportunities or on-site and in-subdrainage basin opportunities do not have a high likelihood of success, after a determination of the natural capacity of the site to mitigate for the impacts. Consideration should include: anticipated wetland mitigation replacement ratios, buffer conditions and proposed widths, hydrogeomorphic classes of on-site wetlands when restored, proposed flood storage capacity, potential to mitigate riparian fish and wildlife impacts (such as connectivity);

2.    Off-site mitigation has a greater likelihood of providing equal or improved wetland functions than the impacted wetland; and

3.    Off-site locations shall be in the same subdrainage basin unless:

a.    Established watershed goals for water quality, flood or conveyance, habitat, or other wetland functions have been established and strongly justify location of mitigation at another site; or

b.    Credits from a state-certified wetland mitigation bank are used as mitigation and the use of credits is consistent with the terms of the bank’s certification; or

c.    The mitigation occurs as part of a city of Centralia-sponsored fee-in-lieu program.

F.    Timing for wetland impacts shall be completed prior to activities that will disturb wetlands. In all other cases, mitigation shall be completed immediately following disturbance and prior to use or occupancy of the activity or development. Construction of mitigation projects shall be timed to reduce impacts to existing fisheries, wildlife, and flora. The director may authorize a one-time temporary delay, up to one hundred twenty days, in completing minor construction and landscaping when environmental conditions could produce a high probability of failure or significant construction difficulties. The delay shall not create or perpetuate hazardous conditions or environmental damage or degradation, and the delay shall not be injurious to the health, safety, and general welfare of the public. The request for the temporary delay must include a written justification that documents the environmental constraints that preclude implementation of the mitigation plan. The justification must be verified and approved by the city and include a financial guarantee.

G.    Mitigation Ratios. The following ratios shall apply to creation or restoration which is in-kind, on-site, timed prior to or concurrent with alteration, and has a high probability of success. These ratios do not apply to remedial actions resulting from unauthorized alterations. The first number specifies the acreage of replacement wetlands and the second specifies the acreage of wetlands impacted.

Category and Type of Wetland Impacts	Reestablishment or Creation	Rehabilitation Only	Reestablishment or Creation (R/C) and Rehabilitation (RH)	Reestablishment or Creation (R/C) and Enhancement (E)	Enhancement Only
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 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 Forested	6:1	12:1	1:1 R/C and 10:1 RH	1:1 R/C and 20:1 E	24:1
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 possible1	6:1 rehabilitation of a natural heritage site1	R/C not considered possible1	R/C not considered possible1	Case-by-case
Category I Bog	Not considered possible1	6:1 rehabilitation of a bog1	R/C not considered possible1	R/C not considered possible1	Case-by-case

1.    Natural heritage sites and bogs are considered irreplacable wetlands because they perform some special 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.

1.    Increased Replacement Ratio. The director may increase the ratios under the following circumstances:

a.    Uncertainty exists as to the probable success of the proposed restoration or creation;

b.    A significant period of time will elapse between impact and replication of wetland functions;

c.    Proposed mitigation will result in a lower category wetland or reduced functions relative to the wetland being impacted; or

d.    The impact was an unauthorized impact.

2.    Decreased Replacement Ratio. The city may decrease these ratios for Category II, III, and IV wetlands under the following circumstances:

a.    Documentation by a qualified wetlands specialist demonstrates that the proposed mitigation actions have a very high likelihood of success;

b.    Documentation by a qualified wetlands specialist demonstrates that the proposed mitigation actions will provide functions and values that are significantly greater than the wetland being impacted;

c.    The proposed mitigation actions are conducted in advance of the impact and have been shown to be successful.

3.    In all cases, a minimum acreage replacement ratio of one-to-one shall be required.

4.    At the discretion of the director, the city may use fees in lieu of reestablishment, rehabilitation, creation or enhancement proposed through mitigation for an established wetlands enhancement program.

H.    Wetlands Enhancement, Cooperative Restoration, and Preservation for Mitigation.

1.    Any applicant proposing to alter wetlands may propose to enhance existing significantly degraded wetlands in order to compensate for wetland losses. Applicants proposing to enhance wetlands must produce a wetland study that identifies how enhancement will increase the functions of the degraded wetland and how this increase will adequately mitigate for the loss of wetland area and function at the impact site. An enhancement proposal must also show whether existing wetland functions will be reduced by the enhancement actions.

2.    A wetlands enhancement compensation project shall be determined pursuant to this section; provided, that enhancement for one function and value will not degrade another function or value and that acreage replacement ratios shall, at a minimum, be doubled to recognize existing functional values. Only Category III and IV wetlands are eligible for enhancement.

3.    Cooperative Restoration. The city may encourage, facilitate, and approve cooperative projects wherein a single applicant or other organization with demonstrated capability may undertake a compensation project with funding from other applicants under the following circumstances:

a.    Restoration, creation or enhancement at a particular site may be scientifically difficult or impossible;

b.    Creation of one or several larger wetlands may be preferable to many small wetlands;

c.    Persons proposing cooperative compensation projects shall submit a joint permit application, demonstrate compliance with all standards, demonstrate the organizational and fiscal capability to act cooperatively, and demonstrate that long-term management can and will be provided.

4.    Wetland Preservation as Mitigation. Impacts to wetlands may be mitigated by preservation of wetland areas in a separate tract or easement, when used in combination with other forms of mitigation such as creation, restoration, or enhancement at the preservation site or at a separate location. Preservation may also be used by itself, but more restrictions as outlined below will apply. Preservation as mitigation is acceptable when done in combination with restoration, creation, or enhancement providing that a minimum of one-to-one acreage replacement is provided by restoration or creation and the criteria below are met:

a.    The impact area is small, and impacts are to a Category III or IV wetland;

b.    Preservation sites include buffer areas adequate to protect the habitat and its functions from encroachment and degradation; and

c.    Mitigation ratios for preservation in combination with other forms of mitigation shall range from ten-to-one to twenty-to-one, as determined by the city, depending on the quality of the wetlands being mitigated and the quality of the wetlands being preserved.

I.    Wetland Mitigation Banks.

1.    Credits from a wetland mitigation bank may be approved for use as compensation for unavoidable impacts to wetlands when:

a.    The bank is certified under Chapter 173-700 WAC; and

b.    The director determines that the wetland mitigation bank provides appropriate compensation for the authorized impacts; and

c.    The proposed use of credits is consistent with the terms and conditions of the bank’s certification.

2.    Replacement ratios for projects using bank credits shall be consistent with replacement ratios specified in the bank’s certification.

3.    Credits from a certified wetland mitigation bank may be used to compensate for impacts located within the service area specified in the bank’s certification. In some cases, bank service areas may include portions of more than one adjacent drainage basin for specific wetland functions.

J.    Wetland Mitigation Monitoring. The mitigation plan shall include a program for monitoring construction of the compensation project and for assessing a completed project. A protocol shall be included outlining the schedule for site monitoring, and how the monitoring data will be evaluated. At a minimum, the monitoring program will continue for at least five years from the date of plant installation. Monitoring will continue for ten years where woody vegetation (forested or shrub wetlands) is the intended result. These communities take at least eight years after planting to reach eighty percent canopy closure. Reporting for a ten-year monitoring period shall occur in years one, two, three, five, seven and ten. A monitoring report shall be submitted as needed to document milestones, successes, problems, and contingency actions of the compensation project. The compensation project shall be monitored for a period necessary to establish that performance standards have been met, but not for a period less than five years. (Ord. 2232 § 5 (Exh. A), 2009).

16.17.080 Mitigation plans.

All wetland restoration, compensation, creation, and/or enhancement projects required pursuant to this chapter either as a permit condition or as the result of an enforcement action shall follow a mitigation plan prepared by qualified wetland professionals approved by the director. Unless waived by the director, in consultation with resource agencies, mitigation plans shall be prepared by qualified wetlands professionals and shall contain the following:

A.    Baseline information for the impacted and any compensation site including written assessment and accompanying maps of the existing acreage; vegetative, faunal and hydrologic conditions; relationship within watershed and to existing water bodies; soil and substrate conditions; topographic elevations; existing and proposed adjacent site conditions; buffers; and ownership;

B.    Specific criteria (including water quality standards, survival rates of planted vegetation, species abundance and diversity targets, or other ecological, geological or hydrological criteria) for evaluating the mitigation proposal relative to the objectives of this chapter and the goals and objectives of the city’s comprehensive plan;

C.    A description of how lost functional values will be replaced;

D.    Specifics on when mitigation will occur relative to project construction and to the requirements of permits required by other jurisdictions;

E.    Detailed construction plans which establish the appropriate methods of construction, sequencing, and times of construction;

F.    Provisions for monitoring the mitigation area to determine whether the mitigation plan is successful. Monitoring of the area shall include:

1.    At a minimum, the monitoring program will continue for at least five years from the date of plant installation. Monitoring will continue for ten years where woody vegetation (forested or shrub wetlands) is the intended result. These communities take at least eight years after planting to reach eighty percent canopy closure. Reporting for a ten-year monitoring period shall occur in years one, two, three, five, seven and ten. A monitoring report shall be submitted as needed to document milestones, successes, problems, and contingency actions of the compensation project;

2.    Provisions for monetary security as established in CMC 16.16.130, Bonds and financial guarantees, in an amount equal to one hundred fifteen percent of the estimated funds necessary to complete work and monitoring in accordance with the mitigation plan, including restoration or rehabilitation to be performed if planned mitigation fails within the designated period of implementation. (Ord. 2232 § 5 (Exh. A), 2009).

16.17.090 Performance standards—Subdivision.

The subdivision and short subdivision of land in wetlands and associated buffers is subject to the following:

A.    Land that is located wholly within a wetland or its buffer may not be subdivided.

B.    Land that is located partially within a wetland or its buffer may be subdivided; provided, that an accessible and contiguous portion of each new lot is located outside of the wetland and its buffer.

C.    Access roads and utilities serving the proposed subdivision may be permitted within the wetland and associated buffers only if the city determines that no other feasible alternative exists and is consistent with other provisions of this title. (Ord. 2232 § 5 (Exh. A), 2009).

16.17.110 Nonconforming activities.

An activity that was approved prior to the passage of this chapter but which is not in conformity with the provisions of this chapter may be continued subject to the provisions of CMC Title 20. (Ord. 2232 § 5 (Exh. A), 2009).

16.17.120 Reasonable use exception.

After it has been determined by the city that losses of wetland are unavoidable and all options have been considered and that all reasonable economic use has been denied, an exception may be applied for and be granted if the permit, on its face or as conditioned, is consistent with CMC 16.16.110, Reasonable use exception, and the following criteria:

A.    The impact is both unavoidable and necessary due to site-specific constraints;

B.    The proposed activity results in no net loss of wetland;

C.    Denial of a permit would cause an extraordinary hardship on the applicant;

D.    In designing the request the applicant shall take deliberate measures to minimize wetland impacts. Steps to minimize impacts to wetlands shall include but are not limited to reduced project scope, sensitive site design, best management practices, off-site construction staging, limiting the season of construction, and consultation with resource agencies in site design.

E.    The hearing examiner may impose any conditions necessary to ensure compliance with the goals of this chapter and the comprehensive plan.

F.    Permitting authority for critical areas within the shoreline jurisdiction is under the shoreline master program (SMP). This section is not applicable to critical areas located within the shoreline jurisdiction unless specifically adopted by the SMP. See Centralia shoreline master program for permitting information in these areas. (Ord. 2396 § 9, 2017: Ord. 2232 § 5 (Exh. A), 2009).

16.17.130 Modification of wetland permits.

A wetland permit holder may request and the city may approve modification of a previously issued wetland permit. (Ord. 2232 § 5 (Exh. A), 2009).

16.17.140 Amendments.

These regulations and the National Wetland Inventory or subsequent Lewis County Wetland Inventory may from time to time be amended in accordance with the procedures and requirements in the general statues and as new information concerning wetland location, soils, hydrology, flooding, or wetland plants and wildlife becomes available. (Ord. 2232 § 5 (Exh. A), 2009).