13.13.020 Wetlands | Bothell Municipal Code

13.13.020 Wetlands.

A. Designating Wetlands. Wetlands are those areas designated in accordance with the approved federal Wetland Delineation Manual and applicable regional supplements that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation adapted for life in saturated soil conditions. All areas within the city meeting the wetland designation criteria in the federal Wetland Delineation Manual, regardless of any formal identification, are hereby designated critical areas and are subject to the provisions of this chapter.

B. Wetland Ratings. Wetlands shall be rated according to the Washington State Department of Ecology wetland rating system found in the Washington State wetland rating system documents (Washington State Wetland Rating System for Western Washington (revised), Department of Ecology Publication No. 14-06-029) or as revised by Ecology. These documents contain the definitions and methods for determining if the criteria below are met:

a. Category I. Category I wetlands are those wetlands that (1) represent a unique or rare wetland type; or (2) are more sensitive to disturbance than most wetlands; or (3) are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or (4) provide a high level of functions. These include bogs, mature and old-growth forested wetlands, wetlands of high conservation value, and wetlands that perform many functions very well (score 23 points or more (out of 27) on a completed rating form for the appropriate hydrogeomorphic class).

b. Category II. Category II wetlands are difficult, though not impossible, to replace, and provide high levels of some functions. These wetlands occur more commonly than Category I wetlands, but still need a relatively high level of protection. Category II wetlands are those that score between 20 and 22 (out of 27) points. These wetlands were judged to perform most functions relatively well, or performed one group of functions very well and the other two moderately well.

c. Category III. Category III wetlands are wetlands with a moderate level of functions (scores between 16 and 19 points out of 27) and can often be adequately replaced with a well-planned mitigation project. These wetlands generally have been disturbed in some ways, and are often less diverse or more isolated from other natural resources in the landscape than Category II wetlands.

d. Category IV. Category IV wetlands have the lowest levels of functions (scores less than 16 points out of 27) and are often heavily disturbed. These are wetlands that should be able to be replaced, and in some cases be able to be improved. However, experience has shown that replacement cannot be guaranteed in any specific case. These wetlands may provide some important functions, and also need to be protected.

2. 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 local government, 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.

C. Mapping. The approximate location and extent of wetlands are shown on the adopted critical area maps. The following critical area maps, including locally adopted maps, are hereby adopted. Additionally, soil maps produced by U.S. Department of Agriculture National Resources Conservation Service may be useful in helping to identify potential wetland areas. These maps are to be used as a guide for the city, project applicants, and/or property owners, and may be continuously updated as new critical areas are identified. They are a reference and do not provide a final critical area designation. The exact location of a wetland’s boundary shall be determined through the performance of a field investigation by a qualified professional wetland scientist applying the approved federal Wetland Delineation Manual and applicable regional supplements.

D. Activities Allowed in Wetlands. The activities listed below are allowed in wetlands in addition to those activities listed in, and consistent with, the provisions established in BMC 13.13.010(K), Activities Allowed Without a Critical Areas Report, and do not require submission of a critical area report, except where such activities result in a loss to the functions and values of a wetland or wetland buffer. These activities include:

1. Conservation or preservation of soil, water, vegetation, fish, shellfish, and other wildlife that does not entail changing the structure or functions of the existing wetland.

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

3. Drilling for utilities under a wetland; provided, that the drilling does not interrupt the groundwater connection to the wetland or percolation of surface water down through the soil column. Specific studies by a hydrologist are necessary to determine whether the groundwater connection to the wetland or percolation of surface water down through the soil column is disturbed.

4. Enhancement of a wetland through the removal of nonnative invasive species. Weeding shall be restricted to hand removal and weed material shall be removed from the site. Bare areas that remain after weed removal shall be revegetated with native shrubs and trees at natural densities. Some hand seeding may also be done over the bare areas with native herbs.

E. Additional Report Requirements. In addition to the general critical area report requirements of BMC 13.13.010(O), critical area reports for wetlands must meet the requirements of this section. Critical area reports for two or more types of critical areas must meet the report requirements for each relevant type of critical area.

1. Preparation by a Qualified Professional. A critical area report for wetlands shall be prepared by a qualified professional who is a certified professional wetland scientist or a noncertified professional wetland scientist with a minimum of five years of experience in the field of wetland science and with experience preparing wetland reports.

2. Area Addressed in Critical Area Report. The following areas shall be addressed in a critical area report for wetlands:

a. The project area of the proposed activity;

b. All wetlands and recommended buffers within 300 feet of the project area; and

c. All shoreline areas, water features, floodplains, and other critical areas, and related buffers within 300 feet of the project area.

3. Wetland Analysis. In addition to the minimum required contents of BMC 13.13.010(O), Critical Areas Report – Requirements, a critical area report for wetlands shall contain an analysis of the wetlands including the following site- and proposal-related information at a minimum:

a. A written assessment and accompanying maps of the wetlands and buffers within 300 feet of the project area, including the following information at a minimum:

(1) Wetland delineation and required buffers;

(2) Existing wetland acreage;

(3) Wetland category;

(4) Vegetative, faunal, and hydrologic characteristics;

(5) Soil and substrate conditions;

(6) Topographic elevations, at two-foot contours; and

(7) 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, evidence of water depths throughout the year – drift lines, algal layers, moss lines, and sediment deposits).

b. 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.

c. A habitat and native vegetation conservation strategy that addresses methods to protect and enhance on-site habitat and wetland functions.

d. Functional evaluation for the wetland and adjacent buffer using the Washington State Wetland Rating System for Western Washington (revised), Department of Ecology Publication No. 14-06-029 and including the reference of the method and all data sheets.

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

(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) Soil and substrate conditions, topographic elevations;

(6) Existing and proposed adjacent site conditions;

(7) Required wetland buffers (including any buffer reduction and mitigation proposed to increase the plant densities, remove weedy vegetation, and replant the buffers);

(8) Property ownership; and

(9) Associated wetlands and related wetlands that may be greater than 300 feet from the subject project.

f. A scale map of the development proposal site and adjacent area. A discussion of ongoing management practices that will protect wetlands after the project site has been developed, including proposed monitoring and maintenance programs.

g. A bond estimate for the installation (including site preparation, plant materials and installation, fertilizers, mulch, stakes) and the proposed monitoring and maintenance work for the required number of years.

h. Title Notification. All activity in critical area protection areas shall be accompanied by a title.

4. Additional Information. When appropriate, the shoreline administrator may also require the critical area report to include an evaluation by the state 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.

a. If the development proposal site contains or is within a wetland area, the applicant shall submit an affidavit, which declares whether the applicant has knowledge of any illegal alteration to any or all wetlands on the proposed site and whether the applicant previously had been found in violation of this chapter. If the applicant has been found previously in violation, the applicant shall declare whether such violation has been corrected to the satisfaction of the jurisdiction.

b. The shoreline administrator shall determine if the mitigation and monitoring plans and bonding measures proposed by the applicant are sufficient to protect the public health, safety, and welfare, consistent with the goals, purposes, objectives and requirements of this chapter.

1. Activities may only be permitted in a wetland or wetland buffer if the applicant can show that short- and long-term impacts of the proposed activity will not degrade the functions and functional performance of the wetland and other critical areas when mitigation is performed in accordance with the preferred sequencing shown in BMC 13.13.010(C).

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

3. Category I Wetlands. Activities and uses shall be prohibited from Category I wetlands, except for low-impact public access and recreation facilities, such as raised boardwalks or platforms for hiking or bird/wildlife watching, that provide opportunities for significant numbers of people to enjoy the natural environment. Such facilities shall be designed to avoid or minimize significant vegetation removal. Projects shall be designed to result in no net loss of ecological functions, and all adverse impacts shall be mitigated.

4. Category II, III and IV Wetlands. With respect to activities proposed in Category II, III, and IV wetlands, the following standards shall apply:

a. Water-dependent activities may be allowed where there are no practicable alternatives that would have a less adverse impact on the wetland, its buffers and other critical areas.

b. Low-impact public access and recreation facilities, such as raised boardwalks, may be allowed if they provide opportunities for substantial numbers of the general public to enjoy the natural environment. Such facilities shall be designed to avoid or minimize significant vegetation removal. Projects shall be designed to result in no net loss of ecological functions, and all adverse impacts shall be mitigated. Public access and recreational facilities shall incorporate interpretive signs or other mechanism to educate the public about wetland functions.

c. Where activities are proposed that are neither water-dependent or related to public access and recreation, it shall be presumed that alternative locations are available, and activities and uses shall be prohibited.

a. Standard buffer widths apply, if the minimization measures of Table 13.13.020-2 are implemented and any existing habitat corridors on the project site are protected. Required standard wetland buffers, based on wetland category and habitat score, are as follows:

Table 13.13.020-1. Wetland Buffer Widths (In Feet)
Wetland Category	Standard (feet) if habitat score is 3 – 4	Buffer (in feet) if 5 habitat points*	Buffer (in feet) if 6 – 7 habitat points*	Buffer (in feet) if 8 – 9 habitat points*
I	75	105	165	225
II	75	105	165	225
III	60	105	165	225
IV	40	40	40	40

*The habitat points are derived from one of three scoring elements (habitat, hydrology and water quality) included in the Washington State Wetland Rating System for Western Washington (revised), Department of Ecology Publication No. 14-06-029.

Table 13.13.020-2. Required Measures to Minimize Impacts to Wetlands
Disturbance	Required Measures to Minimize Impacts
Lights	• Direct lights away from wetland
Noise	• Locate activity that generates noise away from wetland • If warranted, enhance existing buffer with native vegetation plantings adjacent to noise source • 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 wetland buffer
Toxic runoff	• 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	• Retrofit storm water detention and treatment for roads and existing adjacent development • Prevent channelized flow from lawns that directly enters the buffer • Use low-intensity development techniques (for more information refer to the drainage ordinance and manual)
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 best management practices to control dust

(1) Where a legally established roadway transects the buffer, the buffer edge shall extend to the edge of the roadway nearest the wetland.

(2) Where a legally established structure is located within the designated buffer, the buffer edge shall be the edge of the structure.

(3) Where a legally established use or activity is located within the designated buffer, the buffer edge shall extend to the edge of the use or activity.

c. Decreased Buffer Widths. In accordance with an approved critical areas report, buffer widths may be reduced as follows:

(1) Buffer Enhancement. Buffer widths for wetlands may be reduced up to 25 percent of the required width, or to a minimum of 75 feet for Category I and II, 50 feet for Category III, and 25 feet for Category IV wetlands, whichever is greater, when buffer enhancement is performed that increases the existing functions and values beyond that which the wetland would achieve with a standard buffer width. Buffer quality will be evaluated by a qualified wetlands biologist and verified by the city’s third-party biologist; or

(2) Impact Mitigation. The shoreline administrator may approve a reduction in the buffer width if one or more of the following mitigating conditions exist or are provided:

(A) Groundwater Recharge. Where site storm water from impervious surfaces is collected, treated, and infiltrated into the ground above the wetland and the infiltration system is recorded on the title to the property on which it is located; or

(B) Physical Barriers. Where dense vegetation, such as rose and/or hawthorn, is planted at the outer edge of the wetland buffer to minimize animal and/or human intrusion into the wetland.

d. Increased Wetland Buffer Widths. The shoreline administrator shall consider, and may require, increased buffer widths, up to 33 percent of the standard buffer, in accordance with the recommendations of an experienced, qualified professional wetland scientist, and the most current available scientific and technical information, on a case-by-case basis when a larger buffer is necessary to protect existing wetland functions and values based on site-specific characteristics. This determination shall be based on one or more of the following criteria:

(1) A larger buffer is needed to protect other critical areas.

(2) Wetlands within 25 feet of the toe of slopes equal to or greater than 15 percent shall have the following buffers:

(A) Where the horizontal length of the slope including small benches and terraces is within the buffer for that wetland category, the buffer width shall be the greater of the required buffer for that wetland category or 25 feet beyond the toe of the slope.

(B) Where the horizontal length of the slope extends beyond the required buffer for that wetland category, the buffer shall extend to a point 25 feet beyond the required buffer for that wetland category.

(3) The buffer area has minimal vegetative cover. In lieu of increasing the buffer width where existing buffer vegetation is inadequate to protect the existing wetland functions and values, implementation of a buffer planting plan developed by a qualified wetland scientist in accordance with an approved critical areas report may substitute. Existing buffer vegetation is considered “inadequate” and will need to be enhanced through additional native plantings and (if appropriate) removal of nonnative plants when: (A) nonnative or invasive plant species provide the dominant cover, (B) vegetation is lacking due to disturbance and wetland resources could be adversely affected, or (C) enhancement plantings in the buffer could significantly improve buffer functions.

(4) Buffer widths may vary for any one wetland based on its existing characteristics. It is understood that gradual transition zones will be employed between one buffer width and another. The required buffer width may be increased if any of the following circumstances exist:

(A) Species listed by the federal government or the state of Washington as endangered, threatened, sensitive or priority, or essential or outstanding actual habitat for those species, or plant associations of infrequent occurrence are present;

(B) Unusual nesting or resting sites such as heron rookeries or raptor nesting or lookout trees are present;

(C) The wetland has been identified as providing particularly important water quality maintenance or flood control function, or is particularly sensitive to erosion and/or sedimentation.

(5) If the minimization measures in Table 13.13.020-2 are not implemented or existing on-site habitat corridors connecting the subject wetland to WDFW priority habitat are not preserved.

(6) The standard buffer width assumes that the buffer area is well vegetated with native vegetation appropriate for the ecoregion. If the buffer does not consist of vegetation adequate to provide necessary functions and protection, then the buffer shall either be increased by 33 percent or should be planted with native vegetation.

e. Wetland Buffer Width Averaging. The shoreline administrator may allow modification of the standard wetland buffer width in accordance with an approved critical areas report and the most current, available scientific and technical information on a case-by-case basis by averaging buffer widths. Averaging of buffer widths may only be allowed where a qualified professional wetland scientist demonstrates that:

(1) It will not reduce wetland functions or functional performance;

(2) The wetland contains variations in sensitivity due to existing physical characteristics or the character of the buffer varies in slope, soils, or vegetation, and the wetland would benefit from a wider buffer in places and would not be adversely impacted by a narrower buffer in other places;

(3) The total area contained in the buffer area after averaging is no less than that which would be contained within the standard buffer; and

(4) The buffer at its narrowest point is never less than either 75 percent of the required width or 75 feet for Category I and II, 50 feet for Category III, and 25 feet for Category IV, whichever is greater.

(1) All buffers shall be measured from the wetland boundary as surveyed in the field.

(2) 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.

g. Buffer Consistency. All mitigation sites shall have buffers consistent with the buffer requirements of this chapter.

h. Buffer Maintenance. Except as otherwise specified or allowed in accordance with this chapter, wetland buffers shall be retained in an undisturbed or enhanced condition. Removal of invasive nonnative weeds is required for the duration of the mitigation bond.

i. Buffer Uses. The following uses may be permitted within a wetland buffer in accordance with the review procedures of this chapter, provided they are not prohibited by any other applicable law and they are conducted in a manner so as to minimize adverse impacts to the buffer and adjacent wetland:

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

(2) Passive Recreation. Passive recreation facilities designed and in accordance with an approved critical areas report, including:

(A) Walkways and trails; provided, that those pathways that are generally parallel to the perimeter of the wetland shall, where practicable, be located in the outer one-third of the buffer area. Surface permeability of walkways and trails shall be considered where applicable. Raised boardwalks utilizing nontreated pilings area may be acceptable. Buffer widths shall be increased, where practicable, equal to the width of the trail corridor;

(B) Wildlife viewing structures; and

(3) Other Water-Oriented Public Access and Recreation. Consistent with the use allowances for each environment designation, public access and public recreation facilities and their accessory uses and developments may be located in wetland buffers. All such uses and facilities in wetland buffers shall be located to avoid or minimize significant vegetation removal and shall minimize impervious areas. The project shall be designed to result in no net loss of ecological functions, and all adverse impacts shall be mitigated.

(4) Storm Water Management Facilities. Storm water management facilities, except conveyance facilities and dispersion outfalls for which no alternative location is feasible, are prohibited within Category I and II wetland buffers. Storm water management facilities may be located within the outer 25 percent of the buffer of Category III or IV wetlands; provided, that:

(A) No other location is feasible; and

(B) The location of such facilities will not degrade the functions or values of the wetland.

a. Temporary Markers. The outer perimeter of the wetland or buffer and the limits of those areas to be disturbed pursuant to an approved permit or authorization shall be marked in the field in such a way as to ensure that no unauthorized intrusion will occur and is subject to inspection by the shoreline administrator prior to the commencement of permitted activities. This temporary marking shall be maintained throughout construction and shall not be removed until permanent signs, if required, are in place.

b. Permanent Signs. As a condition of any permit or authorization issued pursuant to this chapter, the shoreline administrator may require the applicant to install permanent signs along the boundary of a wetland or buffer.

(1) Permanent signs shall be made of an enamel-coated metal face and attached to a metal post, or another nontreated material of equal durability. Signs must be posted at an interval of one per lot or every 50 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 shoreline administrator:

Protected Wetland Area

Do Not Disturb

Contact the City of Bothell

Regarding Uses and Restriction

(2) The provisions of subsection (F)(8)(a) of this section may be modified as necessary to assure protection of sensitive features or wildlife.

(1) The shoreline administrator shall determine if fencing is necessary to protect the functions and values of the critical area. If found to be necessary, the shoreline administrator shall condition any permit or authorization issued pursuant to this chapter to require the applicant to install a permanent fence at the edge of the wetland buffer, when fencing will prevent future adverse impacts to the wetland.

(2) The applicant shall be required to install a permanent fence around the wetland or buffer when domestic grazing animals are present or may be introduced on site.

(3) Fencing installed as part of a proposed activity or as required in this subsection shall be designed so as to not interfere with species migration, including fish runs, and shall be constructed in a manner that minimizes adverse impacts to the wetland and associated habitat.

G. Compensatory Mitigation Requirements. Compensatory mitigation for alterations to wetlands shall achieve equivalent or greater biologic functions. Compensatory mitigation plans shall be consistent with the state Department of Ecology Wetland Mitigation in Washington State – Part 2: Developing Mitigation Plans (Version 1), Ecology Publication No. 06-06-011b, Olympia, WA, March 2006 or as revised.

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

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

b. Minimizing adverse 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.

c. Rectifying the adverse impact by repairing, rehabilitating, or restoring the affected environment.

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

e. Compensating for the adverse impact by replacing, enhancing, or providing substitute resources or environments.

2. 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:

a. 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

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

3. Preference of Mitigation Actions. Compensatory mitigation actions shall address functions affected by the alteration to achieve functional equivalency or improvement. Mitigation actions that require compensation shall occur in the following order of preference:

a. Restoring wetlands on upland sites that were formerly wetlands. Wetland restoration refers to actions performed to reestablish wetland functional characteristics and processes that have been lost by alterations, activities, or catastrophic events within an area that no longer meets the definition of a wetland.

b. Creating wetlands on disturbed upland sites such as those with vegetative cover consisting primarily of nonnative introduced species. Wetlands creation refers to actions performed to intentionally establish a wetland at a site where it did not formerly exist. Creation 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.

c. Enhancing significantly degraded wetlands in combination with restoration or creation. Enhancement refers to actions performed to improve the condition of existing degraded wetlands so that the functions they provide are of a higher quality. Such enhancement should be part of a mitigation package that includes replacing the impacted area meeting appropriate ratio requirements.

d. Preserving/maintaining a wetland to remove threat or prevent decline, such as purchasing land. Preservation does not result in gain of wetland areas.

4. Type of Mitigation. Compensatory mitigation shall address the functions affected by the proposed project, with an intention to achieve functional equivalency or improvement of functions (“in kind”). The goal shall be for the compensatory mitigation to provide similar wetland functions to those lost, except the city may allow out-of-kind replacement of wetland type or functions when either:

a. The lost wetland provides minimal functions, 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

b. Out-of-kind replacement of wetland type or functions will best meet watershed goals or restoration priorities in the final Lake Washington/Cedar/Sammamish Watershed (WRIA 8) Chinook Salmon Conservation Plan (WRIA 8 Salmon Plan) initially adopted by the city council in 2005, and as updated or supplemented thereafter, or the Shoreline Restoration Plan adopted by the city council in 2013, and as updated thereafter.

a. Compensatory mitigation actions shall be conducted on the site of the alteration except when the applicant can demonstrate that off-site mitigation is ecologically preferable and will provide equivalent or greater replacement of critical area functions and values when compared to on-site mitigation.

b. The city will review applications for off-site mitigation as a shoreline conditional use following the procedures for a Type III development application pursuant to BMC Title 11, Administration of Development Regulations.

c. The city may allow off-site mitigation only when an applicant can demonstrate that a higher level of ecological functioning would result from an alternate approach and when all of the following apply:

(1) There are no reasonable on-site opportunities or on-site opportunities do not have a high likelihood of success, after a determination of the natural capacity of the site to mitigate for the adverse impacts. Consideration shall include: anticipated wetland mitigation replacement ratios; buffer conditions and proposed widths; hydrogeomorphic classes of on-site wetlands when restored; proposed flood storage capacity; position in the landscape; and 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 may include state-certified mitigation banks, federally certified in-lieu-fee programs, applicant-owned properties, or public property subject to agreement with the city.

d. Off-site mitigation, when approved by the city, shall be required in the following order of preference, as illustrated in Figure 13.13.020(G)(5)(d) below:

(1) On an adjacent property in Bothell within the same subdrainage basin on North Creek or Swamp Creek, or on the Sammamish River.

(2) In the same subdrainage basin in Bothell as the impacted wetland when the wetland is located in shoreline jurisdiction associated with North Creek or Swamp Creek, or on the Sammamish River in Bothell when the impacted wetland is located in shoreline jurisdiction associated with the Sammamish River.

(3) Within the shoreline jurisdiction of the city of Bothell or its municipal urban growth area.

(4) In adjacent jurisdictions within the same subdrainage basin on North Creek or Swamp Creek, or on the Sammamish River downstream of Bothell or upstream as far as the 145th Street NE bridge in Woodinville, only when the applicant can demonstrate that the mitigation project will provide equal or greater ecological benefits to the shoreline jurisdiction of the city of Bothell or its municipal urban growth area.

6. Mitigation Banks. The city may approve the use of credits from a certified wetland mitigation bank to compensate for impacts located within the service area specified in the mitigation bank instrument only after the applicant has demonstrated consistency with subsection (G)(5) of this section. If the impacts occur in the service area of more than one bank, the city will give preference to a bank that has implemented restoration actions included in the WRIA 8 Salmon Plan initially adopted by the city council in 2005, and as updated or supplemented thereafter, or the Shoreline Restoration Plan adopted by the city council in 2013, and as updated thereafter. The city may allow the use of credits from a wetland mitigation bank certified under Chapter 173-700 WAC if:

a. The city determines that the proposed use of credits would provide appropriate compensation for the proposed impacts; and

b. The city determines that the proposed use of credits is consistent with the terms and conditions of the certified mitigation bank instrument; and

c. The city determines that the replacement ratios for projects using bank credits are consistent with replacement ratios specified in the certified mitigation bank instrument.

7. In-Lieu-Fee Mitigation. Applicants may use credits from a federally certified approved in-lieu-fee program that implements restoration projects with collected funds only after the applicant has demonstrated consistency with subsection (G)(5) of this section and when all of the following conditions apply:

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

b. The city determines that the proposed use of credits is consistent with the terms and conditions of the federally certified in-lieu-fee program instrument.

c. The applicant’s qualified wetland professional shall calculate the debits associated with the proposed impacts using the credit assessment method specified in the federally approved instrument for the in-lieu-fee program.

d. The proposed impacts must be located within the service area specified in the federally approved in-lieu-fee instrument, and the fees collected by the in-lieu-fee program sponsor will be applied to a project within the impacted area’s subdrainage basin or the same Sammamish River reach. If the program has more than one project available in the subdrainage basin or Sammamish River reach, the city will give preference to the project that will implement restoration actions included in the WRIA 8 Salmon Plan adopted by the city council in 2005, as updated or supplemented thereafter, or the Shoreline Restoration Plan adopted by the city council in 2013, as updated thereafter.

8. Mitigation Timing. Mitigation projects shall be completed with an approved monitoring plan 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 adverse impacts to existing fisheries, wildlife, and flora.

The shoreline administrator may authorize a one-time temporary delay, up to 120 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.

a. Acreage Replacement Ratios. The following ratios shall apply to creation or restoration that is in-kind, is on site, is the same category, is 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; greater ratios shall apply in those cases. These ratios do not apply to the use of credits from a state certified wetland mitigation bank. When credits from a certified bank are used, replacement ratios should be consistent with the requirements of the bank’s certification. The first number specifies the acreage of replacement wetlands and the second specifies the acreage of wetlands altered.

Table 13.13.020-3. Wetland Mitigation Ratios
Category and Type of Wetland Impacts	Reestablishment or Creation	Rehabilitation Only¹	Reestablishment or Creation (R/C) and Rehabilitation (RH)¹	Reestablishment or Creation (R/C) and Enhancement (E)¹	Enhancement Only¹
All Category IV	1.5:1	3:1	1:1 R/C and 1:1 RH	1:1 R/C and 2:1 E	6:1
All Category III	2:1	4:1	1:1 R/C and 2:1 RH	1:1 R/C and 4:1 E	8:1
Category II	3:1	6:1	1:1 R/C and 4:1 RH	1:1 R/C and 8:1 E	Not allowed
Category I forested	6:1	12:1	1:1 R/C and 10:1 RH	1:1 R/C and 20:1 E	Not allowed
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	Not allowed
Category I Natural Heritage site	Not allowed	6:1 Rehabilitation of a Natural Heritage site	Not allowed	Not allowed	Not allowed
Category I bog	Not allowed	6:1 Rehabilitation of a bog	Not allowed	Not allowed	Not allowed

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

b. Increased Replacement Ratio. The shoreline administrator may increase the ratios under the following circumstances:

(1) Uncertainty exists as to the probable success of the proposed restoration or creation;

(2) A significant period of time will elapse between adverse impact and replication of wetland functions;

(3) Proposed mitigation will result in a lower category wetland or reduced functions relative to the wetland being adversely impacted; or

(4) The impact was an unauthorized impact.

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

1. Land that is located wholly within a Category I, II or III wetland or its buffer may not be subdivided.

2. Land that is located partially within a Category I, II or III wetland or its buffer may be subdivided; provided, that an accessible and contiguous portion of each new lot is:

a. Located outside of the wetland and its buffer; and

b. Meets the minimum lot size requirements of BMC Title 12.

3. 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 when consistent with this chapter. (Ord. 2280 § 10, 2019; Ord. 2112 § 3 (Exh. C), 2013).