Section 40.445.030

40.445.030 Protection Standards

A. Consistency With General Purposes. Any activity authorized under this chapter, including activities exempt from a permit pursuant to Section 40.445.040, shall be consistent with the general purposes of this chapter and shall not pose a significant threat to the public health, safety, or welfare.

(Amended: Ord. 2023-03-01; Ord. 2024-03-01)

B. General Standards. Any activity or development subject to a permit under this chapter shall be reviewed and approved, approved with conditions, or denied based on compliance with all of the following criteria. The responsible official may condition permits as necessary to mitigate impacts to wetlands, wetland buffers, and fish and wildlife habitat conservation areas and to conform to the following standards:

1. Mitigation Sequence. Permit applicants must demonstrate that a range of project alternatives have been given substantive consideration with the intent to avoid or minimize impacts to wetlands, wetland buffers, or fish and wildlife habitat conservation areas.

a. The application must demonstrate that the following hierarchy of avoidance and minimization has been pursued:

(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; and

(6) Monitoring the required compensation and taking remedial or corrective measures when necessary.

b. Impacts to wetlands, wetland buffers, and fish and wildlife habitat conservation areas for speculative purposes are prohibited.

c. Impacts to wetlands and fish and wildlife habitat conservation areas with functions and values that cannot be replaced within twenty (20) years shall be avoided unless the activity is authorized under Section 40.445.050.

d. Establishing development envelopes on project plans that clearly avoid wetlands, wetland buffers, and fish and wildlife habitat conservation areas on the proposed plans and preliminary plats complies with Section 40.445.030(B)(1)(a)(1).

e. Activities that affect functions and values of wetlands, wetland buffers, and fish and wildlife habitat conservation areas can only be authorized if the applicant demonstrates that there is no practicable alternative meeting the project purpose and need that would result in less impact to wetlands, wetland buffers, or fish and wildlife habitat conservation areas.

f. Isolated Category IV wetlands less than one-tenth (0.10) acre with a habitat score of five (5) points or less on the rating form and that do not contain federally listed species or their critical habitat are exempt from Section 40.445.030(B)(1)(a)(1) through (B)(1)(a)(4) of the mitigation sequence hierarchy.

2. Standard Requirements. Any action granting or approving a development permit application shall be conditioned on all the following, with each action to be completed by the permittee or the property owner or the permittee’s or owner’s successors, as appropriate:

a. Approved construction limits shall be clearly marked on the site prior to construction and markings shall be maintained until construction is completed.

b. Permanent physical demarcation along the outer extent of the wetlands, wetland buffers, and fish and wildlife habitat conservation areas shall be installed and thereafter maintained. Such demarcation may consist of logs, a tree or hedgerow, fencing, or other prominent physical marking approved by the responsible official.

c. Signs shall be posted at an interval of one (1) per lot or, for lots larger than one-half (1/2) acre, placement approved by the responsible official. Signs shall be worded substantially as follows:

Protected Critical Areas –

Leave in a natural state

d. All wetlands, wetland buffers, and fish and wildlife habitat conservation areas on the lot or lots in which the development is proposed shall be subject to a conservation covenant granted to Clark County and recorded with the county auditor in a form meeting the standards of Section 40.445.070(I).

(1) The responsible official may waive the covenant when:

(a) The development is not compensatory mitigation, does not benefit the landowner, and is located entirely within an easement established prior to the date the application was submitted;

(b) The development is located entirely in a public right-of-way; or

(c) The development is an ecological restoration project that will not be used for compensatory mitigation for other development and is not undertaken to avoid or resolve enforcement action of Title 32.

e. Additional Requirements for Site Plans.

(1) The face of the final site plan shall identify:

(a) All wetlands, wetland buffers, and fish and wildlife habitat conservation areas located within the site; or

(b) Development envelopes approved under Section 40.445.020(A)(4), if any.

(2) A site plan note shall state that any future development or clearing activity within identified wetlands, wetland buffers, or fish and wildlife habitat conservation areas, or outside identified development envelopes must comply with this chapter.

f. Additional Requirements for Plats and Short Plats.

(1) Within the urban growth area wetlands, wetland buffers, and fish and wildlife areas shall be placed in separate unbuildable tracts in plats for single-family homes.

(2) The face of the plat shall identify:

(a) All wetlands, wetland buffers, and fish and wildlife habitat conservation areas located within the plat; and

(b) Development envelopes approved under Section 40.445.020(A)(4), if any.

(3) A plat note shall refer to any previously recorded or concurrent conservation covenant that remains in effect upon recording of the plat.

(4) A plat note shall state that any future development or clearing activity within identified wetlands, wetland buffers, or fish and wildlife habitat conservation areas, or outside identified development envelopes must comply with this chapter.

g. Waivers. The responsible official shall waive the standard requirements in Sections 40.445.030(B)(2)(b) through (B)(2)(d) for the following:

(1) Certain developments where all clearing and development are located within development envelopes approved under Section 40.445.020(A)(4):

(a) All residential building permits and home businesses; and

(b) All site plan reviews and land divisions in the rural area; provided, that the location of development envelopes shall be required for a fully complete application;

(2) The development is not compensatory mitigation, and is located entirely within an easement or lease area established prior to the date the application was submitted;

(3) The development is located entirely in a public right-of-way; or

(4) The development is an ecological restoration project that will not be used for compensatory mitigation for other development and is not undertaken to avoid or resolve enforcement action initiated under Sections 40.445.080(K) and 40.460.745, or Title 32.

3. Permitted Activities. The following activities may be permitted subject to the standards in Section 40.445.030(B)(1); and additional standards in Sections 40.445.030(C)(1)(a), (C)(2)(a), and (C)(3)(a):

a. Clearing and Grading. Clearing of vegetation, disturbance of the soils, placement of fill, and excavation shall only be authorized in conjunction with, or subsequent to:

(1) Entitlement or approval of a proposed development plan under all other applicable standards of this title;

(2) Issuance of a building or grading permit under Title 14;

(3) Execution of a settlement agreement under Title 32; or

(4) Issuance of a determination or mitigated determination of nonsignificance pursuant to Chapter 197-11 WAC (State Environmental Policy Act Rules).

b. Roads, Trails, and Utilities. Crossing wetlands, wetland buffers, or fish and wildlife habitat conservation areas with linear structures or utilities shall be permitted when:

(1) The proposed alignment meets the standards in Section 40.445.030(B)(1);

(2) Native soil and hydrology are maintained or restored to the extent practicable; and

(3) Compensatory mitigation is sufficient to replace functions and values lost due to indirect effects such as habitat fragmentation, reduction in classification, or isolation/loss of wetland buffers.

c. Enhancement and Restoration. Ecological enhancement and restoration projects that are not exempt from obtaining a permit under Section 40.445.040 shall demonstrate that compensatory mitigation for any permanent loss of functions and values for individual wetlands or fish and wildlife habitat conservation areas within the site meets the standards of this section.

d. Mitigation Banking. Creation, restoration, or enhancement of wetlands or fish and wildlife habitat conservation areas to establish credits for use as compensatory mitigation shall be permitted; provided, that bank credit shall not be granted for actions completed prior to issuance of a permit.

e. Conversion From Existing Natural Resource Uses.

(1) Forest Conversions. Conversions of forest lands subject to WAC Title 222 and Section 40.260.080 as follows:

(a) Conversions authorized as a Class IV general, Class I nonexempt, or conversion option harvest plans. The responsible official shall determine functions and values based on the existing conditions at the time of conversion.

(b) Moratorium Waivers. The responsible official may require ecological restoration or compensatory mitigation for areas that have been, or will be, converted to nonforest land based on estimated functions and values of the pre-harvest condition and may consider temporal loss of function where converted lands have not met reforestation requirements of the forest practice permit.

(2) Conversion of Existing Agricultural Uses.

(a) For conversion of uses in compliance with Section 40.445.040(D)(2) the responsible official shall determine functions and values based on the existing conditions at the time of conversion.

(b) For conversion of uses not in compliance with Section 40.445.040(D)(2) the responsible official shall determine estimated functions and values based on conditions at the date of adoption of this chapter.

4. Compensatory Mitigation. Permittees shall compensate for unavoidable impacts by taking actions to restore, replace, preserve, or enhance ecological functions to the extent necessary to ensure no net loss of functions and values.

a. Approaches to Compensatory Mitigation.

(1) Mitigation Credits. Certified mitigation bank or approved in-lieu fee program (ILF) credits may be used to provide compensatory mitigation as follows:

(a) The responsible official determines that the credits provide ecologically appropriate compensation for the proposed impacts;

(b) The impact site is located in the service area, or an out-of-service area credit purchase has been authorized as specified in the establishing instrument; and

(c) The calculation of debits and proposed use of credits are consistent with the terms and conditions of the establishing instrument.

(2) Permittee-Responsible Mitigation. The permittee constructs, installs, and maintains compensatory mitigation after the permit is issued and is held responsible for completion and performance for an established maintenance period.

(a) There are no mitigation bank or ILF credits available or the responsible official concludes that available credits are not more ecologically appropriate than the proposed mitigation plan; and

(b) The mitigation is located at the site of the permitted impacts or at an off-site location in ecologically appropriate setting.

b. Timing of Compensatory Mitigation. Compensatory mitigation must be completed, to the extent practicable, immediately following disturbance and prior to recording, use, or occupancy of the development.

(1) The permittee may submit a request for a delay in completion of mitigation construction that includes:

(a) Explanation for the need for the delay.

(b) A performance assurance with a term no longer than one (1) year if one is not already in place.

(2) If mitigation is not completed within two (2) years of the impact, the responsible official may increase the amount of mitigation required to offset additional loss of functions and values caused by the delay in completing the mitigation.

5. Maintenance and Monitoring of Compensatory Mitigation. Mitigation actions that require construction, planting, or treatment of nonnative vegetation require periodic maintenance in order to succeed. The responsibility to maintain mitigation is with the permittee (including successors); however, the responsible official may recommend specific maintenance actions as part of the permit review or subsequent to the inspection process during the maintenance period.

a. Maintenance Period.

(1) The length of the maintenance period is dependent upon the complexity of the mitigation plan and the time frame in which the mitigation is expected to fully replace functions and values. Minimum maintenance periods for different elements of a mitigation action are listed in Table 40.445.030-1. The responsible official may specify a period for elements not listed or require a longer period to ensure that compensatory mitigation goals are met.

(a) The maintenance period for a mitigation plan is determined by the element that demands the longest period. The permittee may limit performance monitoring of specific elements with shorter periods after the minimum period for that element, but all elements must be maintained throughout the maintenance period.

(2) The maintenance period begins (year 0) when the responsible official deems the mitigation construction or installation complete in accordance with Section 40.445.080(I)(2)

Table 40.445.030-1. Minimum Maintenance Periods (Years)
Mitigation Element	Permit Review Threshold (see Section 40.445.080(A)(1))
Mitigation Element	Level 1	All Other
Habitat Structures	1	1
Herbaceous Cover	1	1
Invasive Vegetation Management	3	5
Riparian Planting	3	5
Shrub Cover	3	5
Tree Protection	5	5
Wetland Hydrology	5	5
Nonriparian Tree Cover/Canopy Release	5	10

b. Monitoring and Reporting Required. When a maintenance period is required, the permittee shall provide periodic reports (see Section 40.445.070(I)) to the responsible official based on the schedule in the approved monitoring plan. Default reporting schedules for typical maintenance periods are listed in Table 40.445.030-2. Permittees are encouraged to monitor performance in years during the maintenance period that reporting is not required to ensure that the mitigation will meet performance standards in the next reporting year.

Table 40.445.030-2. Default Reporting Schedule
Maintenance Period	Year
Maintenance Period	1	2	3	4	5	6	7	8	9	10
1 Year	x
3 Years	x	x	x
5 Years	x	x	x		x
10 Years	x	x	x		x		x			x

c. Adaptive Management. An adaptive management approach shall be used when mitigation is not meeting performance expectations and modifications to the mitigation plan, including monitoring, maintenance, and contingency plans, are necessary.

d. Maintenance Assurance. A financial assurance to the county for the maintenance period shall be required for mitigation plans that exceed two hundred (200) plants or cover more than three-tenths (0.3) acre of total area. The responsible official may require a maintenance assurance for a smaller mitigation plan if the mitigation actions have a significant risk of failure over time without maintenance and construction cost exceeds five thousand dollars ($5,000).

(Amended: Ord. 2023-03-01; Ord. 2024-03-01)

C. Specific Standards for Critical Areas and Buffers. Permitted activities shall meet the specific performance standards for wetlands, wetland buffers, and fish and wildlife habitat conservation areas as applicable.

1. Specific Standards for Wetlands.

a. Permitted Activities in Wetlands. The following additional activities are allowed in wetlands subject to the standards of Section 40.445.030(B)(1):

(1) Conversion to Upland. Placement of fill or installation of drainage to convert wetlands to uplands consistent with the stated purpose of the proposed development.

(2) Conversion to Wetland Buffer. Reduction in the functional area of wetlands due to buffer reductions that are not authorized under Section 40.445.030(C)(2).

(a) Conversions for placement of roads and utilities.

(b) Conversion caused by wetland alterations authorized under Section 40.445.030(C)(1)(a)(1).

(c) Conversions for other development. Compensatory mitigation for converted wetlands shall comply with the standards in Section 40.445.030(C)(1)(b).

(3) Stormwater Management Facilities. A wetland may be physically or hydrologically altered to meet the requirements of an LID or flow control BMP if all of the following criteria are met:

(a) The wetland is rated as Category III or IV with a habitat score less than six (6) points;

(b) The affected wetland area does not contain a breeding population of native amphibians or potential amphibian breeding habitat (per Question H 1.5 on the wetland rating form);

(d) The hydrologic functions of the wetland can be improved as indicated by one (1) or more of the following characteristics:

(i) Ditches or drain tiles effectively draining the wetland;

(ii) Manmade isolation from adjacent flooding (i.e., dikes);

(iii) Fill that can be removed to increase effective flood storage;

(iv) One (1) or more culverts that are lower than the natural outlet of the wetland; or

(v) The wetland is part of a priority restoration plan that achieves restoration goals identified in a shoreline master program or other local or regional watershed plan.

b. Compensatory Mitigation for Wetlands.

(1) Types of Wetland Mitigation Actions. The various types of wetland mitigation actions allowed are listed below in the general order of preference.

(a) 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:

(i) 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. Reestablishment results in a gain in wetland acres, and, therefore, functions. Activities could include removing fill material, plugging ditches, or breaking drain tiles.

(ii) Rehabilitation. The manipulation of the physical, chemical, or biological characteristics of a site with the goal of returning natural or historic functions to a degraded wetland. Rehabilitation results 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.

(b) Creation (Establishment). The manipulation of the physical, chemical, or biological characteristics of a site with the goal of developing a wetland on an upland or deepwater site where a wetland did not previously exist. Establishment results in a gain in wetland acres, and, therefore, functions. 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.

(c) Enhancement. The manipulation of the physical, chemical, or biological characteristics of a wetland site to heighten, intensify, or improve the 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, flood water 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.

(d) Protection/Maintenance (Preservation). Removing a threat to, or preventing the decline of, wetland conditions by an action in or near a wetland. This includes the purchase of land or easements repairing water control structures or fences, or structural protection such as repairing a barrier island. This term also includes activities commonly associated with the term “preservation.” Preservation does not result in a gain of wetland acres but may result in improved wetland functions.

(2) Location of Permittee-Responsible Mitigation. Compensatory mitigation actions shall generally be conducted within the same watershed (Figure 40.445.030-1) and on the site of the alteration except when the applicant can demonstrate that off-site mitigation is ecologically preferable. The following criteria will be evaluated when determining whether the proposal is ecologically preferable:

Figure 40.445.030-1

Clark County Watershed Map

(a) There are no reasonable opportunities on site or within the watershed. Considerations should include anticipated replacement ratios for wetland mitigation, buffer conditions and required widths, available hydrology, proposed flood storage capacity, and potential to enhance or connect to fish and wildlife habitat conservation areas.

(b) On-site mitigation would require elimination of functional upland habitat connecting the mitigation to other wetlands or fish and wildlife habitat conservation areas.

(c) Off-site mitigation has a greater likelihood of providing equal or improved wetland functions than the altered wetland.

(d) Off-site locations are in the same watershed (see Figure 40.445.030-1) or are ecologically appropriate pursuant to published statewide interagency guidance for wetland mitigation.

(3) Standard Wetland Mitigation Ratios. The following mitigation ratios for each of the mitigation types described in Section 40.445.040(D)(1)(c) apply:

Table 40.445.030-3. Standard Wetland Mitigation Ratios (In Area)
Wetland to Be Replaced	Reestablishment or Creation	Rehabilitation	Reestablishment or Creation and Rehabilitation	Reestablishment or Creation and Enhancement	Enhancement
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
Category III	2:1	4:1	1:1 R/C and 2:1 RH	1:1 R/C and 4:1 E	8:1
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, Wetland of High Conservation Value	Not Considered Possible	6:1 Rehabilitate a Wetland of High Conservation Value	N/A	N/A	Case-by-Case

(4) Preservation. Permanent protection of wetlands and associated buffer may be proposed for compensatory mitigation if all of the following criteria are met:

(a) The approval authority determines that the proposed preservation is the best mitigation option;

(b) The proposed preservation site is under threat of undesirable ecological change due to permitted, planned, or likely actions that will not be adequately mitigated under existing regulations;

(c) The area proposed for preservation is of high quality or critical for the health of the watershed or basin due to its location. Some of the following features may be indicative of high-quality sites:

(i) Category I or II wetland rating (using the wetland rating system for western Washington);

(ii) Rare or irreplaceable wetland type (for example, bogs, mature forested wetlands, estuarine wetlands) or aquatic habitat that is rare or a limited resource in the area;

(iii) Adjacency or connectivity to fish and wildlife habitat conservation areas or other wetlands;

(iv) The mitigation site is a priority site identified in an adopted watershed plan.

(d) Permanent preservation of the wetland and buffer will be provided through a conservation easement or tract held by an appropriate natural land resource manager, such as a land trust. The responsible official may approve other legal and administrative mechanisms in lieu of a conservation easement if it determines they are adequate to protect the site; and

(e) Ratios for preservation in combination with other forms of mitigation range from ten to one (10:1) to thirty to one (30:1), as determined on a case-by-case basis, depending on the rating of the wetlands being replaced and the extent to which the preservation site meets the approval criteria above. Ratios for preservation as the sole means of compensatory mitigation shall be at least twenty to one (20:1).

(5) Reduced Ratios. The responsible official has the authority to reduce wetland mitigation ratios under the following circumstances:

(a) Compensatory mitigation is completed in advance of the impact. Ratios shall be reduced from the standard ratios in Table 40.445.030-3 based on the performance of the mitigation at the time of application; or

(b) Lower mitigation ratios are derived from use of a published methodology that the responsible official finds suitable for use in Clark County for quantifying functional equivalency between wetland impacts and wetland mitigation actions.

2. Specific Performance Standards for Wetland Buffers.

a. Permitted Buffer Reductions.

(1) Minimum Buffer Width. Wetland buffer widths shall not, at any location, be reduced, except as allowed under Section 40.445.030(C)(2)(a)(2), to less than the greater of:

(a) Seventy-five percent (75%) of the required buffer; or

(b) The applicable low intensity land use water quality buffer in Table 40.445.020-3.

(2) Buffer Averaging. Buffer boundaries may be modified by averaging buffer widths. If buffer averaging is used, the following criteria apply:

(a) The buffer shall not be reduced from the required width by more than twenty-five percent (25%) in any location; and

(b) The total area contained in the buffer, after averaging, shall be functionally equivalent to the area contained within the buffer prior to averaging.

(i) Buffer functions in replacement areas may be restored or enhanced to meet this criterion.

(ii) The responsible official shall determine the replacement ratio required to meet this criterion.

(3) Mitigation of High Land Use Intensity Development. High intensity buffers may be reduced by twenty-five percent (25%) if:

(a) All of the minimization measures in Table 40.445.030-4 are applied to the extent that they are applicable to the site; and

(b) For wetlands with a moderate or high habitat function (more than five (5) points on the habitat section of the rating system form), a permanently protected, relatively undisturbed, vegetated corridor at least one hundred (100) feet wide is provided that meets one (1) or more of the following criteria:

(i) The corridor provides a direct connection to priority habitats, compensatory mitigation sites, wildlife areas/refuges, national, county, and state parks where they have management plans with identified areas designated as natural, natural forest, or natural area preserve; or

(ii) The corridor is an area that is the site of a watershed project identified within, and fully consistent with, a watershed plan as defined by RCW 89.08.460; or

(iii) The corridor is an area where development is prohibited according to the provisions of the local shoreline master program; or

(iv) The corridor is an area with equivalent habitat quality that is in permanent conservation status as recognized by WDFW.

Table 40.445.030-4 Required Measures to Minimize Impacts of High Intensity Uses (Table 40.445.020-3) to Wetlands (Measures are required if applicable to a specific proposal.)
Disturbance	Activities and Uses That Cause Disturbances	Required Measures to Minimize Impacts
Lights	• Parking lots • Commercial/industrial • Residential • Recreation (e.g., athletic fields) • Agricultural buildings	• Direct lights away from wetland • Only use lighting where necessary for public safety and keep lights off when not needed • Use motion-activated lights • Use full cut-off filters to cover light bulbs and direct light only where needed • Limit use of blue-white colored lights in favor of red-amber hues • Use lower-intensity LED lighting • Dim light to the lowest acceptable intensity
Noise	• Commercial • Industrial • Recreation (e.g., athletic fields, bleachers, etc.) • Residential • Agriculture	• Locate activity that generates noise away from wetland • Construct a fence to reduce noise impacts on adjacent wetland and buffer • Plant a strip of dense shrub vegetation adjacent to wetland buffer
Toxic runoff	• Parking lots • Roads • Commercial/industrial • Residential areas • Application of pesticides • Landscaping • Agriculture	• Route all new, untreated runoff away from wetland while ensuring wetland is not dewatered • Establish covenants limiting use of pesticides within 150 ft. of wetland • Apply integrated pest management (These examples are not necessarily adequate for minimizing toxic runoff if threatened or endangered species are present at the site.)
Stormwater runoff	• Parking lots • Roads • Residential areas • Commercial/industrial • Recreation • Landscaping/lawns • Other impermeable surfaces, compacted soil, etc.	• Retrofit stormwater detention and treatment for roads and existing adjacent development • Prevent channelized or sheet flow from lawns that directly enters the buffer • Infiltrate or treat, detain, and disperse new runoff from impervious surfaces and lawns
Pets and human disturbance	• Residential areas • Recreation	• Use privacy fencing • Plant dense native vegetation to delineate buffer edge and to discourage disturbance • Place wetland and its buffer in a separate tract • Place signs around the wetland buffer every 50-200 ft., and for subdivisions place signs at the back of each residential lot • When platting new subdivisions, locate greenbelts, stormwater facilities, and other lower-intensity uses adjacent to wetland buffers
Dust	• Tilled fields • Roads	• Use best management practices to control dust

b. Permitted Activities. The following additional activities are allowed in wetland buffers subject to the standards of Section 40.445.030(B)(1):

(1) Stormwater Facilities.

(a) Dispersion Facilities. Stormwater dispersion facilities that comply with the standards of Chapter 40.386 shall be allowed in all wetland buffers. Stormwater outfalls for dispersion facilities shall comply with the standards in subsection (C)(2)(b)(2) of this section. Enhancement of wetland buffer vegetation to meet dispersion requirements may also be considered as buffer enhancement for the purpose of meeting the buffer averaging or buffer reduction standards in this section.

(b) Stormwater facilities authorized under Section 40.445.030(C)(1)(a)(3) that provide equivalent or enhanced buffer function.

(c) Other stormwater facilities are only allowed in the outer twenty-five percent (25%) of buffers of wetlands with low habitat function (less than six (6) points on the habitat section of the rating system form); provided, that existing buffer functions are maintained. Unless determined otherwise by the responsible official, the following activities shall be considered to reduce the existing buffer functions when they are associated with the construction of a stormwater facility:

(i) Removal of trees greater than four (4) inches diameter at four and one-half (4 1/2) feet above the ground or greater than twenty (20) feet in height;

(ii) Disturbance of plant species that are listed as rare, threatened or endangered by the county or any state or federal management agency;

(iii) The construction of concrete structures other than manholes, inlets, and outlets that are exposed above the normal water surface elevation of the facility;

(iv) The construction of maintenance and access roads;

(v) Slope grading steeper than four to one (4:1) horizontal to vertical above the normal water surface elevation of the stormwater facility;

(vi) The construction of pretreatment facilities such as forebays, sediment traps, and pollution control manholes;

(vii) The construction of trench drain collection and conveyance facilities;

(viii) The placement of fencing; and

(ix) The placement of rock and/or riprap, except for the construction of flow spreaders, or the protection of pipe outfalls and overflow spillways; provided, that buffer functions for areas covered in rock and/or riprap are replaced.

(2) Road and Utility Crossings. Crossing buffers with new roads and utilities is allowed subject to the standards of Section 40.445.030(B)(1); provided, that wetland and buffer functions are restored or replaced.

(3) Other Activities in Wetland Buffers. Regulated activities not involving stormwater management, road and utility crossings, buffer conversion, or a buffer reduction are allowed in the buffer if all the following conditions are met:

(a) The activity is temporary and will cease or be completed within three (3) months of the date the activity begins;

(b) The activity will not result in a permanent structure in or under the buffer;

(d) The activity will not result in a reduction of wetland acreage or function.

3. Specific Performance Standards for Fish and Wildlife Habitat Conservation Areas.

a. Avoidance and Minimization Measures. The following avoidance and minimization measures shall be applied in fish and wildlife habitat conservation areas pursuant to Section 40.445.030(B)(1):

(1) Preserving important functions and natural habitat features by limiting clearing or alteration;

(2) Using existing stream crossings whenever practicable;

(3) Implementing best management practices (BMPs) and integrated management practices such as:

(a) Utilizing low impact development BMPs in design and construction;

(b) Seasonally restricting construction activities;

b. Permitted Activities.

(1) Stream Crossings. New stream crossings shall conform to the water crossing structure standards in WAC 220-660-190 (hydraulic code rules).

(2) In-Stream Work. All work below the OHWM of a stream shall conform to the standards in WAC 220-660-110 (in-water work times) and WAC 220-660-120 (in-water construction practices).

c. Compensatory Mitigation.

(1) Types of Habitat Mitigation Actions. The various types of habitat mitigation actions allowed are listed below.

(a) Restoration and Enhancement. Restoring native plant communities or altering physical habitat characteristics in an ecologically appropriate manner within existing fish and wildlife habitat conservation areas to improve or restore habitat functions and values.

(b) Creation. Altering native plant communities or physical habitat characteristics in a manner designed to add new or increase the total area of an existing fish and wildlife habitat conservation area.

(c) Riparian Averaging. Reduction of riparian habitat area width in one location and replacement in another on the site such that the total riparian habitat area increases or remains unchanged and habitat functions and values within the site are maintained. Land beyond the two hundred (200) year site potential tree height from the OHWM of a stream is not part of the riparian habitat area and cannot be used for riparian averaging.

(d) Long-Term Habitat Protection. Use of legal instruments to identify and protect fish and wildlife habitat conservation areas, such as conservation covenants or conservation easements.

(e) Site-Specific Mitigation Actions. The responsible official may authorize other mitigation actions that replace fish and wildlife habitat conservation area functions and values.

(2) Location of Permittee-Responsible Mitigation. Compensatory mitigation actions shall generally be conducted on the site of the alteration except when the applicant can demonstrate that:

(a) On-site mitigation is not practicable; or

(b) Off-site mitigation is ecologically preferable.

(3) Mitigation Amount. The amount of compensatory mitigation necessary to meet the performance standards in Section 40.445.030(B)(3) shall be evaluated on a case-by-case basis.

(4) The responsible official may maintain habitat mitigation guidelines and solicit recommendations from WDFW.

(Amended: Ord. 2023-03-01; Ord. 2024-03-01)