Chapter 14.40
WETLANDS

Sections:

14.40.010    Purpose.

14.40.020    Identification, delineation, mapping, and rating.

14.40.030    Buffer standards – Wetlands.

14.40.040    Wetland review procedures.

14.40.050    Allowed activities.

14.40.060    Mitigation requirements.

14.40.070    Appendices.

14.40.010 Purpose.

A. The purpose of this chapter is to avoid or, in appropriate circumstances, to minimize, rectify, reduce, or compensate for impacts arising from land development and other activities affecting wetlands, and to maintain and enhance the biological and physical functions and values of wetlands with respect to water quality maintenance, stormwater and floodwater storage and conveyance, fish and wildlife habitat, primary productivity, recreation, education, and historic and cultural preservation. When wetland impacts occur, mitigation will be required to achieve no net loss of wetlands in terms of acreage, function, and value.

B. This chapter is intended to be consistent with the requirements of Chapter 36.70A RCW and to implement the goals and policies of the city’s comprehensive plan for protecting wetlands. (Ord. 17-513 § 3 (Exh. A)).

14.40.020 Identification, delineation, mapping, and rating.

A. Designation. All areas within the city meeting the definition of “wetland” in Chapter 14.20 EMC are hereby designated as critical areas.

B. Identification and Delineation.

1. Wetlands shall be identified and delineated by a qualified wetland specialist in accordance with the approved federal wetland delineation manual and applicable regional supplements.

2. A wetland delineation is valid for five years, after which date the city shall require verification that the wetland boundaries and prior conditions have not changed to determine whether a revision or additional assessment is needed.

C. Mapping.

1. The approximate location and extent of wetlands are shown on maps maintained by the city.

2. These maps are useful as a guide for project applicants and property owners, but the maps do not provide a conclusive or definitive indication of a wetland presence or its extent.

3. Wetlands may exist that do not appear on the maps and some wetlands that appear on the maps may not meet all of the wetland designation criteria.

D. Rating. Wetlands shall be rated according to the Washington Department of Ecology Wetland Rating System, as set forth in the Washington State Wetland Rating System for Western Washington: 2014 Update (Ecology Publication No. 14-06-029, or as revised and approved by the Department of Ecology).

E. Illegal Modifications. Wetland rating categories shall not change due to illegal modifications made by the applicant or with the applicant’s knowledge. (Ord. 17-513 § 3 (Exh. A)).

14.40.030 Buffer standards – Wetlands.

A. Determining Buffer Widths. Buffer widths shall be measured horizontally from the perpendicular line established at the wetland edge as shown in Table 14.40.030.1. Note that Table 14.40.030.1 is reduced wetland buffers with minimization of impacts. See Table 14.40.030.3 for buffers that apply without minimization techniques.

B. The following 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: 2014 Update (Ecology Publication No. 14-06-029, or as revised and approved by Ecology). The adjacent land use intensity is assumed to be high.

1. For wetlands that score five points or more for habitat function, the buffers in Table 14.40.030.1 can be used if both of the following criteria are met:

a. A relatively undisturbed, vegetated corridor at least 100 feet wide is protected between the wetland and any other priority habitats as defined by the Washington Department of Fish and Wildlife.

i. The latest definitions of priority habitats and their locations are available on the WDFW website at: http://wdfw.wa.gov/hab/ phshabs.htm.

ii. The corridor must be protected for the entire distance between the wetland and the priority habitat by some type of legal protection such as a conservation easement.

iii. Presence or absence of a nearby habitat must be confirmed by a qualified biologist. If no option for providing a corridor is available, Table 14.40.030.1 may be used with the required measures in Table 14.040.030.2 alone.

b. The measures in Table 14.40.030.2 are implemented, where applicable, to minimize the impacts of the adjacent land uses.

2. For wetlands that score three to four habitat points, only the measures in Table 14.40.030.2 are required for the use of Table 14.40.030.1

Table 14.40.030.1

Buffer Standards – Wetlands 

Wetland Category

Buffer Width (Wetland scores 3-4 habitat points)

Buffer Width (Wetland scores 5 habitat points)

Buffer Width (Wetland scores

6-7 habitat points)

Buffer Width (Wetland scores

8-9 habitat points)

Category I:

Based on total score

75 ft.

105 ft.

165 ft.

225 ft.

Category I: Bogs and wetlands of high conservation value

190 ft.

190 ft.

190 ft.

225 ft.

Category I: Forested

75 ft.

105 ft.

165 ft.

225 ft.

Category II (all)

75 ft.

105 ft.

165 ft.

225 ft.

Category III (all)

60 ft.

105 ft.

165 ft.

225 ft.

Category IV (all)

40 ft.

40 ft.

40 ft.

40 ft.

C. Required Measures to Minimize Impacts to Wetlands. Measures to minimize the impacts of the land use adjacent to wetlands shall be applied as shown in Table 14.40.030.2.

Table 14.40.030.2

Wetland Impact Minimization Measures 

Disturbance

Required Measures to Minimize Impacts

Lights

• Direct lights away from any wetland

Noise

• Locate activity that generates noise away from any wetland

• For activities that generate relatively continuous, potentially disruptive noise, such as certain heavy industry or mining, establish an additional 10-foot heavily vegetated buffer strip immediately adjacent to the outer buffer

Toxic runoff

• Route all new, untreated runoff away from any wetland while ensuring the wetland is not dewatered

• Establish covenants limiting use of pesticides within 150 feet of wetlands

• Apply integrated pest management

Stormwater runoff

• Retrofit stormwater detention and treatment for roads and existing adjacent development

• Prevent channelized flow from lawns that directly enters the buffer

• Use low impact development techniques

Change in water regime

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

Pets and human disturbance

• Use privacy fencing or 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 or protect with a conservation easement

Dust

• Use BMPs to control dust

D. Modification of Buffer Widths. The standard buffer widths of subsection (A) of this section may be modified by averaging or increasing.

1. Buffer Averaging. Buffer width averaging may be allowed only where the applicant demonstrates all of the following through the submittal of a wetland report that is prepared by a qualified professional:

a. Buffer encroachment is unavoidable;

b. The wetland contains variations in sensitivity due to existing physical characteristics;

c. Width averaging will provide equal or greater protection of current wetland functions and values;

d. The total buffer area after averaging is no less than the buffer area prior to averaging;

e. The width of the buffer at any given point after averaging shall be no smaller than 75 percent of the standard buffer;

f. The averaging is accomplished within the project boundaries; and

g. Measures will be taken to ensure that there is no loss of wetland function due to the buffer averaging.

2. Buffer Increases.

a. The department may require increased buffer width(s) when any of the following are identified:

i. A larger buffer is necessary to maintain viable populations of existing species;

ii. The wetland is used by, or associated with, species listed by the federal government or the state as endangered, threatened, sensitive, or as documented priority species or habitats, or essential or outstanding potential sites such as heron rookeries or raptor nesting areas;

iii. The adjacent land is susceptible to severe erosion and erosion control measures will not effectively prevent adverse wetland impacts;

iv. The adjacent land has minimal vegetative cover, or slopes greater than 20 percent.

b. If an applicant chooses not to apply the wetland impact minimization measures identified in Table 14.40.030.2, then the wetland buffers applicable to the site shall be per Table 14.40.030.3.

Table 14.40.030.3

Wetland Buffers without Minimization of Impacts 

Wetland Category

Buffer Width (Wetland scores 3-4 habitat points)

Buffer Width (Wetland scores 5 habitat points)

Buffer Width (Wetland scores

6-7 habitat points)

Buffer Width (Wetland scores

8-9 habitat points)

Category I:

Based on total score

100 ft.

140 ft.

220 ft.

300 ft.

Category I: Bogs and wetlands of high conservation value

250 ft.

300 ft.

Category I: Forested

100 ft.

140 ft.

220 ft.

300 ft.

Category II (all)

100 ft.

140 ft.

220 ft.

300 ft.

Category III (all)

80 ft.

140 ft.

220 ft.

300 ft.

Category IV (all)

50 ft.

(Ord. 17-513 § 3 (Exh. A)).

14.40.040 Wetland review procedures.

A. Wetland Report Requirements. If the department’s maps indicate that a proposed project may be located within 300 feet of a wetland, the applicant shall submit a wetland critical areas report prepared by a qualified wetland specialist. The report requirement may be waived if the department determines that there are no potential direct or indirect impacts on the wetland or its buffers that would result from the proposed development. Wetland critical areas reports shall comply with the requirements of this chapter.

B. Single-Family Dwelling Wetland Review. Construction of a single-family dwelling and regulated activities accessory to a single-family dwelling, such as driveways, gardens, fences, walls, lawns, or on-site septic systems, may utilize an alternative wetland review procedure, subject to the following:

1. Prior to issuance of a building permit, site development permit, or on-site sewage system permit, the applicant shall submit a single-family wetland certification form completed by a wetland specialist that certifies either:

a. No regulated wetlands are present within 300 feet of the project area; or

b. Wetlands are present within 300 feet of the project area, but the buffer does not extend onto the project site.

2. The single-family certification form may be used only to authorize single-family dwellings and accessory structures. It may not be used for new agricultural activities, expansion of existing agricultural activities, forest practices activities, commercial projects, land divisions, or buffer width modifications. (Ord. 17-513 § 3 (Exh. A)).

14.40.050 Allowed activities.

A. The three types of wetlands identified in subsections (A)(1) through (3) of this section are exempt from the requirement to avoid impacts in EMC 14.10.070(B) and may be altered if the impacts are fully mitigated based on the remaining mitigation sequencing actions in EMC 14.10.070(B). In order to verify the following conditions, a wetland critical areas report meeting the requirements of EMC 14.40.070, Appendices, must be submitted:

1. All isolated Category IV wetlands less than 4,000 square feet that:

a. Are not associated with riparian areas or their buffers;

b. Are not part of a wetland mosaic;

c. Are not associated with shorelines of the state or their associated buffers;

d. Do not score five or more points for habitat functions based on current version of the Washington State Wetland Rating System for Western Washington (Ecology, 2014);

e. Do not contain a priority habitat or a priority area for a priority species identified by the Washington Department of Fish and Wildlife, federally listed species or their critical habitat, or habitats of and species of local importance as identified in Chapter 14.50 EMC.

2. Wetlands less than 1,000 square feet that meet the criteria specified in subsection (A)(l) of this section.

3. Utility projects within the outer 25 percent of any wetland buffers which have minor or short-duration impacts, as determined by the department in accordance with the criteria below, and which do not significantly impact the function or values of wetlands; provided, that such projects are constructed with BMPs and additional restoration measures are provided. Minor activities shall not result in the transport of sediment or increased stormwater. Such allowed minor utility projects shall meet the following criteria:

a. There is no practical alternative to the proposed activity with less impact on wetlands;

b. The activity involves the placement of a utility pole, street signs, anchor, or vault or other small component of a utility facility; and

c. The activity involves disturbance of an area less than 75 square feet.

B. The activities listed below are allowed in wetlands and their buffers, except where such activities would result in a loss of the functions and values of a wetland or wetland buffer. A critical areas report must be submitted to the department to determine if function or value will be lost. These activities include:

1. Activities in wetlands in areas managed according to a special area management plan or other plan adopted by the department and specifically designed to protect wetland resources.

2. Trimming of vegetation for purposes of providing a view corridor will be allowed. The trimming is limited to a maximum 20-foot width and the benefit to fish and wildlife habitat may not be reduced. No more than 30 percent of the live crown of a tree may be removed. Trimming shall be limited to hand pruning of branches and vegetation and does not include felling, topping, or the removal of trees.

a. Trimming and limbing of vegetation for the creation and maintenance of view corridors shall occur in accordance with the pruning standards of the International Society of Arboriculture. (See articles published by the International Society of Arboriculture, Consumer Information Program, updated July 2005.)

b. The activity will not increase the risk of landslide or erosion.

3. Drilling for utilities or utility corridors under a wetland, with an entrance or exit portal located completely outside of the wetland buffer; provided, that the drilling does not interrupt the groundwater connection to the wetland or percolation of surface water down through the soil column. Specified studies by a hydrologist are necessary to determine whether the groundwater connection to the wetland or percolation of surface water down through the soil column will be disturbed. (Ord. 17-513 § 3 (Exh. A)).

14.40.060 Mitigation requirements.

A. Mitigation. Compensatory mitigation is required for all unavoidable alterations to wetlands or their buffers, except for buffer averaging when done in accordance with this chapter. Compensatory mitigation actions shall replace functions affected by the alteration and shall provide equal or greater functions compared to the impacted wetland. All projects must first demonstrate compliance with EMC 14.10.070(B) prior to development of compensatory mitigation plans.

B. Preference of Mitigation Actions. Compensatory mitigation of wetland areas shall occur in the following order of preference:

1. Restoration. The manipulation of the physical, chemical, or biological characteristics of a site with the goal of returning natural or historic functions to a former or degraded wetland. For the purpose of tracking net gains in wetland acres, restoration is divided into:

a. Reestablishment. The manipulation of the physical, chemical, or biological characteristics of a site with the goal of returning natural or historic functions to a former wetland. The reestablishment must result in a gain in wetland acres and functions. Activities could include removing fill material, plugging ditches, or breaking drain tiles.

b. Rehabilitation. The manipulation of the physical, chemical, or biological characteristics of a site with the goal of repairing natural or historic functions of a degraded wetland. The rehabilitation must result in a gain in wetland function but does not result in a gain in wetland acres. Activities could involve breaching a dike to reconnect wetlands to a floodplain or return tidal influence to a wetland

2. Creation. The manipulation of the physical, chemical, or biological characteristics of a site to develop a wetland on an upland or deep water site where a wetland did not previously exist. Creation results in a gain in wetland acres. Activities typically involve excavation of upland soils to elevations that will produce a wetland hydroperiod, create hydric soils, and support the growth of hydrophytic plant species.

3. Enhancement. The manipulation of the physical, chemical, or biological characteristics of a wetland site to heighten, intensify, or improve specific function(s) or to change the growth stage or composition of the vegetation present. Enhancement is undertaken for specified purposes such as water quality improvement, floodwater retention, or wildlife habitat. Enhancement results in a change in some wetland functions and can lead to a decline in other wetland functions, but does not result in a gain in wetland acres. Activities typically consist of planting vegetation, controlling nonnative or invasive species, modifying site elevations or the proportion of open water to influence hydroperiods, or some combination of these activities.

C. Approaches to Compensatory Mitigation. Mitigation for alterations to wetland and their buffers shall rely on the approaches listed below:

1. Wetland Mitigation Banks. Credits from a certified wetland mitigation bank may be used to compensate for impacts within the service area specified in the mitigation bank instrument. Use of credits from a wetland mitigation bank certified under Chapter 173-700 WAC is allowed if:

a. The department determines that it would provide appropriate compensation for the proposed impacts;

b. The impact site is located in the service area of the bank;

c. The proposed use of credits is consistent with the terms and conditions of the certified bank instrument; and

d. Replacement ratios for projects using bank credits is consistent with replacement ratios specified in the certified mitigation bank instrument.

2. In-Lieu Fee Mitigation. Credits from an approved in-lieu fee program may be used when all the following apply:

a. The approval authority determines that it would provide environmentally appropriate compensation for the proposed impacts.

b. The proposed use of credits is consistent with the terms and conditions of the approved in-lieu fee program instrument.

c. Projects using in-lieu fee credits shall have debits associated with the proposed impacts calculated by the applicant’s qualified wetland specialist using the credit assessment method specified in the approved instrument for the in-lieu fee program.

d. The impacts are located within the service area specified in the approved in-lieu fee instrument.

3. Permittee-Responsible Mitigation. In this situation, the permittee performs the mitigation after the permit is issued and is ultimately responsible for implementation and success of the mitigation. Permittee-responsible mitigation may occur at the site of the permitted impacts or at an off-site location within the same watershed. If available, the use of wetland mitigation banks and in-lieu fee programs are preferable to permittee-responsible mitigation.

D. Wetland Mitigation Ratios. The ratios listed in Table 14.40.060 apply to permittee-responsible mitigation. The first number specifies the acreage of replacement wetlands required, and the second number specifies the acreage of wetlands altered or relocated.

Table 14.40.060

Wetland Mitigation Ratios 

Category and Type of Wetland

Creation or Reestablishment

Rehabilitation

Enhancement

Category I: High conservation value/bog

Not considered possible

Not considered possible

Not considered possible

Category I: Mature and old growth forest

6:1

12:1

24:1

Category I: Based on functions

4:1

8:1

16:1

Category II

3:1

6:1

12:1

Category III

2:1

4:1

8:1

Category IV

1.5:1

3:1

6:1

The director may increase the ratios under the following circumstances:

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

2. Significant period of time between destruction and replication of wetland values;

3. Projected losses in functional value; or

4. The compensatory mitigation is off site.

E. Wetland Buffer Mitigation. To mitigate unavoidable impacts to functions and values of wetland buffers, a minimum buffer ratio of 1:1 (alteration area: mitigation area) is required. This ratio assumes that creation or restoration of a wetland buffer with appropriate native vegetation is sufficient to compensate for the wetland buffer functions and values affected by alteration of an existing wetland buffer. If enhancement of an existing buffer is proposed as mitigation, a higher mitigation ratio may be required. For any proposed buffer activities, the applicant must demonstrate that the functions and values of the altered buffer will be fully replaced by the proposed mitigation. The department may increase the buffer mitigation ratios under the following circumstances:

1. The replacement ratio needed to recover the lost functions and values of buffer area is greater than 1:1 based upon the existing type of vegetative cover of either the impact site or the proposed mitigation site;

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

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

4. The impact was an unauthorized impact.

F. Wetland and Buffer Mitigation Plans. Compensatory wetland mitigation plans shall be consistent with Wetland Mitigation in Washington State – Part 2: Developing Mitigation Plans (Ecology, 2006); and Selecting Wetland Mitigation Sites Using a Watershed Approach (Ecology, 2009), or as revised. Mitigation plans shall comply with the requirements established in EMC 14.40.070(B). (Ord. 17-513 § 3 (Exh. A)).

14.40.070 Appendices.

A. Wetland Report.

B. Wetland Mitigation Plan.

APPENDIX A

WETLAND REPORT

A. A wetland critical areas report shall, at a minimum, include the following:

1. The general critical areas report requirements in EMC 14.10.080;

2. Map showing the location of all wetlands and required buffers within 300 feet of the proposed development;

3. An analysis of the on-site wetland(s) include the following site- and proposal-related information:

a. Documentation of any fieldwork performed on the site, including, but not limited to, field delineation data sheets for delineations and wetland rating forms;

b. Wetland acreage;

c. Wetland category;

d. A discussion of the water sources supplying the wetland and documentation of hydrologic regime (locations of inlet and outlet features, water depths throughout the wetland, evidence of recharge or discharge);

e. A discussion of the functions of existing wetlands, including vegetative, faunal, and hydrologic conditions; and

f. A description of the methodologies used to conduct the wetland delineations;

4. A discussion of measures, including avoidance, minimization, and mitigation, proposed to preserve existing wetlands;

5. A detailed discussion of the direct and/or indirect potential impacts on the wetland by the project; and

6. The wetland mitigation plan requirements of Appendix B of this section, if the activity will result in unavoidable impacts to wetlands or their buffers.

APPENDIX B

WETLAND MITIGATION PLAN

A. A wetland mitigation plan shall, at a minimum, include the general mitigation plan requirements in EMC 14.10.090 and the following information:

1. Existing and proposed wetland acreage;

2. Vegetative and faunal conditions;

3. Surface and subsurface hydrologic conditions including an analysis of existing and future hydrologic regime and proposed hydrologic regime for enhanced, created, or restored mitigation areas;

4. Relationship within watershed and to existing water bodies;

5. Soils and substrate conditions, topographic elevations;

6. Existing and proposed adjacent site conditions;

7. Required wetland buffers (including any buffer reduction or averaging and mitigation proposed to enhance buffers);

8. Property ownership;

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

10. A bond estimate for the installation, site preparation, plant materials and installation, fertilizers, mulch, and the proposed monitoring and maintenance work for the required number of years, pursuant to EMC 14.10.070(E). (Ord. 17-513 § 3 (Exh. A)).