i. The plants are removed using hand labor and/or light equipment;

ii. Soil disturbance is minimized, and no filling or modification of soil contours occurs;

iii. Water quality is protected and there is no modification of hydrology patterns within the critical area or buffer;

iv. Use of pesticides, insecticides, herbicides, and fertilizers within critical areas and their buffers shall be allowed on a case-by-case basis as part of the City of Sammamish Integrated Pest Management Policy, consistent with King County Noxious Weed Control Board best management practices, and in accordance with state and federal laws. In accord with Washington State Department of Ecology requirements, aquatic-approved pesticides and adjuvants are required in seasonally or permanently wet environments;

v. Native plants are protected from removal or damage;

vi. All removed plant material shall be taken away from the site and disposed of properly;

vii. Appropriate erosion-control measures are used;

viii. The area is replanted within one growing season with a like kind and density of native vegetation following nonnative plant removal; and

ix. Removal of nonnative or invasive plants authorized under this subsection shall not require a critical areas report.

i. Replace with appropriate native trees on site at the ratios designated in the tree replacement standards (SMC 21.03.060.J);

ii. Demonstrate critical area functions will be restored through a critical areas report (subsection I.3 of this section) and vegetation management plan (subsection O of this section). Restoration actions may include invasive plant removal and revegetation with shrub and groundcover plants where on-site tree replacement is determined by a qualified professional to be unsustainable.

iii. When on-site tree replacement or restoration cannot be achieved, then off-site planting is allowed within protected open space, or critical areas and their buffers within Sammamish City limits. Off-site planting may be achieved through purchase of credits from an in-lieu fee program if available that supports off-site tree planting equivalent to tree replacement requirements within the City.

i. Removal or discontinuance of the existing improvement or nonconformance is necessary to meet water quality, drainage, or revegetation requirements or to qualify for incentives.

ii. The existing improvement or nonconformance is a use no longer allowed in the zoning designation or would be incompatible with a proposed use.

iii. Removal or discontinuance of the existing improvement or nonconformance is necessary for public health, safety, or welfare, including but not limited to adequate sanitation, access, and/or safe walking conditions.

i. Landslide Hazard Areas. If the existing legally created single detached dwelling unit(s) and accessory dwelling unit(s) and associated impervious surfaces are located within the building setback or buffer required for a landslide hazard area, a critical areas report must be supplied consistent with the provisions of subsection I.3 of this section and approved by the City that demonstrates that there will be no increased risk to life or property by the proposed footprint expansion.

ii. Aquatic and Habitat Resources. If an existing legally created single detached dwelling unit and an accessory dwelling unit and associated impervious surfaces are located within the building setback or buffer for a stream, wetland, or within a fish and wildlife habitat conservation area, the following must be met:

i. Landslide Hazard Areas. If the existing legally created building(s) and associated impervious surfaces are located within the building setback or buffer required for a landslide hazard area, a critical areas report must be supplied consistent with the provisions of subsection I.3 of this section and approved by the City that demonstrates that there will be no increased risk to life or property by the proposed footprint expansion.

ii. Aquatic and Habitat Resources. If an existing legally created building(s), and associated impervious surfaces, are located within the building setback or buffer for a stream or wetland, or within a fish and wildlife habitat conservation area:

i. There is no other feasible alternative to the activity or proposed development with less impact to the critical area; and

ii. The activity or development proposal is designed to avoid, minimize, and mitigate the impact to environmentally critical areas consistent with the avoidance and mitigation sequencing requirements in this chapter; and

iii. The proposed use does not pose a threat to the public health, safety, or welfare.

i. The application of this chapter would deny all reasonable use of the property;

ii. There is no other reasonable economic use with less impact to the critical area;

iii. The proposed development does not pose an unreasonable threat to the environment or public health, safety, or welfare on or off the development proposal site and is consistent with the general purposes of this chapter and the public interest;

iv. Any alterations permitted to the critical area or buffer shall be the minimum necessary to allow for reasonable use of the property and the project design must follow mitigation sequencing as outlined in subsection K of this section and achieve no net loss of ecological functions; and any authorized alteration of a critical area under this subsection shall be subject to conditions established by the Department including, but not limited to, mitigation under an approved mitigation plan; and

v. The lack of a reasonable economic use alternative is not the result of actions taken by the applicant.

i. A critical areas report from a qualified professional detailing how the project has been designed to avoid and minimize impacts to the critical area and buffer. The report shall detail the anticipated impact on the critical area and buffer along with specific mitigation measures that may include restoration of previously impacted critical area.

ii. A site plan showing the critical area, buffer, natural features, topography, and proposed development area.

iii. A proposed monitoring plan for a minimum of five years, including submittal of an annual report to the City outlining how proposed mitigation measures are functioning, such as plantings.

iv. The applicant shall submit a detailed review of the permitted uses allowed in the underlying zoning district with supporting information explaining why all other permitted uses that may have less impact to the critical area and buffer are not feasible, including transfer of development rights (TDRs) (SMC 21.06.070) as an alternative economic use.

v. A neighborhood land analysis on a form provided by the City adopted by the Director that evaluates the surrounding conditions in the immediate vicinity to verify that the request is consistent with the criteria included in subsection F.2 of this section.

i. Confirm whether critical areas or buffers have been mapped or identified within the distance equal to the largest potential required buffer applicable to the development proposal area;

ii. Confirm the nature and type of the critical area;

iii. Determine whether a critical areas report is required;

iv. Evaluate the critical areas report and require third-party review, if necessary;

v. Determine whether the development proposal is consistent with this chapter;

vi. Determine whether any proposed alteration to the critical area is necessary; and

vii. 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.

i. There will be no alteration of the critical area or buffer;

ii. The development proposal will not have an impact on the critical area in a manner contrary to the goals, purposes, objectives, and requirements of this chapter; and

iii. The minimum standards required by this chapter are met; or

iv. Critical areas are located off site and access to applicable off-site property is restricted.

i. The applicant shall disclose to the City the presence of critical areas on the development proposal site and any mapped or identifiable critical areas within the distance equal to the largest potential required buffer applicable to the development proposal area on the applicant’s property;

ii. Documentation of any fieldwork and desktop review performed by qualified professional(s) to identify, map, and classify critical areas in the project vicinity as described in subsection I.3.a.i of this section;

iii. Assessment of the impacts or risks to an environmentally critical area or buffer:

iv. A description of efforts made to apply mitigation sequencing pursuant to subsection K of this section to avoid, minimize and mitigate impacts to environmentally critical areas;

v. Analysis of the proposal for conformance with applicable critical area development standards in subsections T through X of this section;

vi. Studies that propose adequate mitigation, maintenance, monitoring, and contingency plans and bonding measures as necessary to offset impacts to the critical area from the development proposal;

vii. A scale map of the development proposal site;

viii. Photographic records of the site before the proposed alteration occurs;

ix. Detailed studies, as required by this chapter, for individual critical areas or as otherwise deemed necessary for critical areas protection by the Director;

x. Assessment of potential impacts that may occur downstream or downhill from the development site, such as sedimentation or erosion, where applicable;

xi. Assessment of potential impacts to lake management areas, and other areas designated for special protection, where applicable; and

xii. Consideration of the protection recommendations of the Lake Washington/Cedar/Sammamish Watershed Chinook Salmon Conservation Plan – WRIA 8 Steering Committee and adopted sub-basin plans.

i. Protect, restore, or enhance the habitat, natural drainage, or other valuable functions of the aquatic resource resulting in a net improvement to the aquatic resource and its buffer;

ii. Design, implement, maintain, and monitor a restoration or enhancement plan prepared by a qualified professional or document other approved mitigation bank use or in-lieu fee plan;

iii. Perform the restoration or enhancement under the direction of a qualified professional; and

iv. Will otherwise be consistent with the purposes of this chapter and state and federal requirements.

i. Qualified professionals for preparing geotechnical reports and geotechnical design recommendations for erosion hazard areas must be a geotechnical engineer with a professional civil engineering license or geotechnical reports and geotechnical design recommendations must be prepared by a geotechnical engineer with a professional civil engineer, licensed by the state of Washington.

ii. Demonstrate that the proposed development substantially improves water quality by showing all of the following:

i. Geotechnical reports and geotechnical design recommendations associated with alteration or modification of a landslide hazard or protective regulations must be prepared jointly by both a geotechnical engineer with a professional civil engineering license and a licensed geologist, licensed by the state of Washington.

ii. The critical areas report for a landslide hazard area shall also include the following:

i. Restoration. Restoring the impacted critical areas by repairing, rehabilitating, or restoring the affected critical area or its buffer.

ii. Preservation or Maintenance. Reducing or eliminating the impact or hazard over time by preservation or maintenance operations during the life of the development proposal, activity or alteration.

iii. Compensation. Compensating for the adverse impact by replacing or enhancing critical areas and their buffers or creating substitute critical areas and their buffers as required in this chapter.

i. Plats;

ii. Short plats;

iii. Parks;

iv. Other development proposals, including but not limited to multifamily, mixed use, and commercial development where the Director determines that such fencing is necessary to protect the functions of the critical area;

i. Areas of historic failures, such as:

ii. Areas that have shown movement during the Holocene epoch, from 10,000 years ago to the present, or which are underlain or covered by mass wastage debris of that epoch;

iii. Areas with all three of the following characteristics:

iv. Areas with a slope of 40 percent or steeper and with a vertical relief of 10 or more feet except areas composed of consolidated rock. A slope is delineated by establishing its toe and top, as defined in SMC 21.04.040.B, and measured by averaging the inclination over at least 10 feet of vertical relief;

v. Slopes that are parallel or subparallel to planes of weakness (such as bedding planes, joint systems, and fault planes) in subsurface materials;

vi. Slopes having gradients steeper than 80 percent subject to rock fall during seismic shaking;

vii. Areas potentially unstable because of rapid stream incision, stream bank erosion, and undercutting by wave action;

viii. Unconsolidated glacial deposits subject to elevated groundwater levels after prolonged rainfall or rain-on-snow events as designation criteria for a landslide hazard area; and

ix. Areas located in a canyon or an active alluvial fan, presently or potentially subject to inundation by debris flows or catastrophic flooding.

i. Construction outside of this seasonal development limitation may be authorized if the Director determines that the hazard area will not be adversely impacted by the proposed construction work, or the applicant demonstrates that erosion hazards will be fully mitigated through a temporary erosion and sediment control management plan that includes:

ii. In addition to the requirements of this section, the Director may require additional studies of the site hydrology, soils, and stormwater retention, and may also require grading, structural improvements, erosion control measures, restoration plans, and/or an indemnification/release agreement.

iii. Construction activity associated with subdivisions, short subdivisions, and similar projects that drain to Lake Sammamish during the wet season shall provide water quality monitoring reports to the City.

iv. The Director may halt wet season construction as necessary to protect the hazard area and/or to prevent downstream impacts.

i. Existing vegetation shall be retained on lots until building permits are approved for development by the Department;

ii. If any vegetation on the lots is damaged or removed during construction of the subdivision infrastructure, the applicant shall be required to submit an erosion control plan to the Department for review and approval. Following approval, the applicant shall be required to implement the plan.

i. A landslide hazard area located on a slope 40 percent or steeper may be altered only if the alteration meets the following standards and limitations:

ii. A landslide hazard area located on a slope less than 40 percent may be altered only if the alteration meets the following requirements:

iii. Neither buffers nor a critical area tract shall be required if the alteration meets the standards of subsection T.4.e.ii of this section.

i. Slopes that are 40 percent or steeper with a vertical elevation change of up to 20 feet if no adverse impact will result from the exemption based on the City’s review of and concurrence with a soils report prepared by a licensed geologist or geotechnical engineer; and

ii. The approved regrading of any slope that was created through previous legal grading activities.

i. The evaluation of site-specific subsurface conditions shows that the proposed development site is not located in a seismic hazard area; or

ii. Mitigation based on the best available engineering and geological practices is implemented that either eliminates or minimizes the risk of damage, death, or injury resulting from surface rupture, seismically induced settlement, landsliding, lateral spreading, or soil liquefaction.

i. Activities that generate runoff must be treated to preserve water quality and remove potential contaminants, including biological oxygen demand (BOD), fecal coliform, nutrients, oil, grease, and total suspended solids (TSS);

ii. Stormwater runoff from roads and highways must be treated to preserve water quality and remove pollutants from vehicles, including polynuclear aromatic hydrocarbons (PAHs), lead, zinc, copper, cadmium, as well as sediments (soil particles) and road salt;

iii. Runoff from industrial activities must be treated to preserve water quality including the removal of heavy metals, sediments, and a broad range of manmade organic pollutants, including phthalates, PAHs, and other petroleum hydrocarbon;

iv. Residential activities must include stormwater treatment methods to preserve water quality and remove road-based pollutants, as well as herbicides, pesticides, nutrients, bacteria, and viruses, where applicable; and

v. Activities shall be designed to prevent impacts from toxic organics, such as per- and polyfluoroalkyl substances (PFAS), pollutants from rubber preservatives (including 6PPD-q), and polychlorinated biphenyls (PCBs), to the extent practicable.

i. Retail sale of containers five gallons or less in size, where there are less than 500 total gallons; and

ii. Hazardous materials of no risk to the aquifer.

i. Information regarding geologic and hydrogeologic characteristics of the site including the surface location of all CARA classes located on site or immediately adjacent to the site and permeability of the unsaturated/vadose zone;

ii. Groundwater depth, flow direction and gradient;

iii. Data on wells and springs within 1,300 feet of the project area;

iv. Location of other critical areas, including surface waters, within 1,300 feet of the project area;

v. Historic hydrogeologic data for the area to be affected by the proposed activity;

vi. Presumptive best management practices (BMPs) and integrated pest management (IPM) proposed to be used; and

vii. At the discretion of the Director permitting of stormwater infiltration or injection facilities in CARA 1 and CARA 2 areas may require a demonstrative BMP approach;

viii. Discussion of the effects of the proposed project on the groundwater quality and quantity, including:

i. Criteria used to determine the need for site monitoring shall include, but not be limited to, the proximity of the facility to production or monitoring wells, the type and quantity of hazardous materials on site, and whether or not the hazardous materials are stored in underground vessels.

ii. The City may employ an outside consultant at the applicant’s expense to review the monitoring plan and analysis, to ensure that the monitoring plan is followed, and that corrective actions are completed.

i. In all CARA classes, vehicle repair and servicing must be conducted over impermeable pads, with containment curbs, and within a covered structure capable of withstanding normally expected weather conditions. Chemicals used in the process of vehicle repair and servicing must be stored in a manner that protects them from weather and provides containment should leaks occur.

ii. In all CARA classes, no dry wells shall be allowed on sites used for vehicle repair and servicing. Dry wells existing on the site prior to facility establishment must be abandoned using techniques approved by the State Department of Ecology prior to commencement of the proposed activity.

i. Residential Use. In all CARA classes, use of household pesticides, herbicides, and fertilizers shall not exceed times, rates, concentrations and locations specified on the packaging.

ii. Other Uses. In Class 1 and 2 CARA areas, proposed developments with maintained landscape areas greater than 10,000 square feet in area shall prepare an operations and maintenance manual using best management practices (BMPs) and integrated pest management (IPM) for fertilizer and pesticide/herbicide applications. The BMPs shall include recommendations on the quantity, timing and type of fertilizers applied to lawns and gardens to protect groundwater quality.

i. A hydrogeologic report prepared by a qualified professional hydrogeologist shall be provided that includes an analysis to assess the risks to the specific aquifer and viability of the proposed infiltration and/or UIC. In addition to the report requirements described in subsection U.5.c of this section, the analysis shall also include:

i. Source location of imported fill;

ii. Previous land uses of the source location; and

iii. Whether or not fill to be imported is native, undisturbed soil.

i. The system is approved by the Seattle-King County Department of Public Health and the system either uses an upflow media filter system or a proprietary packed-bed filter system or is designed to achieve approximately 80 percent total nitrogen removal for typical domestic wastewater; or

ii. The Seattle-King County Department of Public Health determines that the systems required under subsection U.7.e.i of this section will not function on the site.

i. The system is approved by the Washington Department of Ecology as compliant with the provisions of Chapter 173-160 WAC, or as amended; and

ii. A notice on title is recorded documenting the maintenance requirements of the geothermal/heat exchange wells.

i. Category 1. Category 1 wetlands include those that receive a score of greater than or equal to 23 through 27 points based on functions, or those that are rated Category 1 based on special characteristics as defined in the rating form.

ii. Category 2. Category 2 wetlands include those that receive a score of 20 through 22 points based on functions, or those that are rated Category 2 based on special characteristics as defined in the rating form.

iii. Category 3. Category 3 wetlands include those that receive a score of 16 through 19 points based on functions.

iv. Category 4. Category 4 wetlands include those that score equal to or less than 15 points based on functions.

i. A relatively undisturbed, vegetated corridor at least 100 feet wide is protected between the wetland and:

ii. If the features described in subsection V.1.e.i of this section are not present, mitigated buffers shall be allowed through demonstrated use of applicable measures listed in the Impact Minimization Measures Table above.

iii. The corridor is permanently protected for the entire distance between the wetland and the shoreline or legally protected area by a conservation easement, deed restriction, or other legal site protection mechanisms.

iv. Presence or absence of the shoreline or priority habitat must be confirmed by a qualified biologist or Shoreline Administrator.

v. The measures in the Impact Minimization Measures Table above are implemented, as applicable, to minimize the impacts of the adjacent land uses.

vi. For wetlands that score five or fewer habitat points, only the measures in the Impact Minimization Measures Table above are required for use of mitigated buffers.

vii. If an applicant does not apply the mitigation measures or does not provide a protected corridor when a potential corridor is available, then the standard buffers shall be used.

viii. The mitigated narrower buffer widths in the table above assume the buffer is vegetated with a native plant community appropriate for the ecoregion. If the existing buffer does not meet vegetative buffer standards, is unvegetated, sparsely vegetated, or vegetated with invasive species that do not perform needed functions, the buffer must either be densely planted to create the appropriate native plant community or apply the wider buffer widths in the buffer table above to ensure that the buffer provides adequate functions to protect the wetland.

ix. Where a legally established, constructed street, or legally established development transects a wetland buffer, the Department may approve a modification of the standard buffer width to the edge of the interruption if the isolated part of the buffer does not provide additional protection of the wetland and provides insignificant biological, geological or hydrological buffer functions relating to the wetland. If the resulting buffer distance is less than 75 percent of the standard buffer for the applicable wetland category, no further reduction shall be allowed.

x. In addition to the provisions of subsection E of this section, where a buffer has been previously established on a legally created parcel or tract that was legally established according to the regulations in place at the time of establishment, and is permanently recorded on title or placed within a separate tract, and the parcels that are included on the plat at the time of recording of the subject parcel or tract, then the buffer shall remain as previously established, provided:

xi. Where wetland functions have been improved due to voluntary implementation of an approved stewardship, restoration and/or enhancement plan that is not associated with required mitigation or enforcement, the wetland buffer width shall be determined based on the previously established wetland category and habitat score as documented in the approved stewardship and enhancement plan.

i. It will provide additional protection to wetlands or enhance their functions, as long as the total area contained in the buffer on the development proposal site does not decrease (see also SMC 21.06.020.F.2.e for buffer compensation requirements for trails);

ii. 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;

iii. The buffer width is not reduced to less than 75 percent of the standard buffer width at any location;

iv. The buffer width is decreased on one part of a wetland and increased on another part of the same wetland feature; and

v. The buffer is associated with a development proposal, and it will not further encumber a neighboring property not owned by the applicant.

i. Fish and wildlife habitat conservation area and habitat connections are present;

ii. Landslide or erosion hazard areas are contiguous to wetlands;

iii. Groundwater recharge and discharge areas are at risk;

iv. Or to offset buffer impacts, such as trail and utility corridors; and

v. Ecological wetland functions are at risk including, but not limited to, the following:

i. Protect, restore or enhance the wildlife habitat, natural drainage, or other valuable functions of the wetland resulting in a net improvement to the functions of the wetland system;

ii. Design, implement, maintain, and monitor a mitigation plan prepared by a qualified professional;

iii. Perform the mitigation under the direction of a qualified professional; and

iv. Will otherwise be consistent with the purposes of this chapter.

i. The Director determines that no feasible alternative location is available; and

ii. The utility corridor meets any additional requirements for installation, replacement of vegetation and maintenance, as needed to mitigate impacts.

i. The applicant demonstrates that the sewer line location is necessary for gravity flow;

ii. The corridor is not located in a wetland or buffer used by species listed as endangered or threatened by the state or federal government or containing critical or outstanding actual habitat for those species or heron rookeries or raptor nesting trees;

iii. The corridor alignment including, but not limited to, any allowed maintenance roads follows a path farthest from the wetland edge as feasible;

iv. Corridor construction and maintenance protects the wetland and buffer and is aligned to avoid cutting trees greater than 12 inches in diameter at breast height, when possible, and pesticides, herbicides and other hazardous substances are not used;

v. An additional, contiguous and undisturbed buffer, equal in width to the proposed corridor, including any allowed maintenance roads, is provided to protect the wetland;

vi. The corridor is revegetated with appropriate native vegetation at preconstruction densities or greater immediately upon completion of construction or as soon thereafter as possible, and the sewer utility ensures that such vegetation survives;

vii. Any additional corridor access for maintenance is provided, to the extent possible, at specific points rather than by a parallel road; and

viii. The width of any necessary parallel road providing access for maintenance is as small as possible, but not greater than 15 feet; the road is maintained without the use of herbicides, pesticides or other hazardous substances; and the location of the road is contiguous to the utility corridor on the side away from the wetland.

i. The existing and zoned density around the wetland is three dwelling units per acre or more;

ii. At least 75 percent of the lots around the wetland have been built upon and no significant buffer or wetland vegetation remains on these lots; and

iii. Open water is at least 50 percent of the wetland.

i. The crossing is identified as a part of a corridor shown in a City-adopted parks or trails plan, park master plan, transportation plan, or comprehensive plan, or otherwise is necessary to connect or construct the road or trail to publicly owned lands, utility corridors, rights-of-way or other public infrastructure, or is required to provide access to property where no other feasible alternative access is possible; or the applicant demonstrates that the new crossing creates less overall or less incremental impacts to critical areas and habitat than the use of an existing corridor while still achieving overall project goals and objectives;

ii. All crossings avoid or minimize impact to the wetland and provide mitigation for unavoidable impacts through restoration, enhancement or replacement of disturbed areas as described in this chapter and in the SMC;

iii. Crossings do not significantly change the overall wetland hydrology;

iv. Crossings do not diminish the flood storage capacity of the wetland; and

v. All crossings are constructed during summer low water periods.

i. The restoration is approved by all agencies with jurisdiction;

ii. The restoration is not associated with mitigation of a specific development proposal;

iii. The restoration is limited to revegetation of wetlands and their buffers and other specific fish and wildlife habitat improvements that result in a net improvement to the functions of the wetland system;

iv. The restoration should be completed in accordance with best management practices (BMPs) and acceptable standards consistent with best available wetland science to minimize impacts to wetlands; and

v. The restoration is performed under the direction of a qualified professional.

i. There are no feasible on-site opportunities for mitigation, or on-site opportunities do not have a high likelihood of success due to development pressures, adjacent land uses, or on-site buffers or connectivity are inadequate;

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

iii. Off-site locations have been identified and evaluated in the following order of preference:

i. Wetland Mitigation Ratios. The following ratios shall apply to required wetland mitigation. The first number specifies the acreage of replacement wetlands and the second specifies the acreage of wetlands altered.

ii. Wetland Buffer Replacement Ratio. Altered wetland buffer area shall be replaced at a minimum ratio of one-to-one; provided, that the replacement ratio may be increased at the Director’s discretion to replace lost functions and values.

iii. Increased Mitigation Ratio. The Director may increase the ratios under the following circumstances:

iv. Decreased Mitigation Ratio. The Director may decrease these ratios under the following circumstances:

v. Minimum Mitigation Ratio. In all cases of permanent wetland impacts, a minimum acreage replacement ratio of one to one shall be required.

i. A mitigation plan for restoration conforming to the requirements of this chapter and section shall be provided.

ii. On sites where nonnative vegetation was cleared, restoration shall include installation of native vegetation with a density equal to or greater than the prealtered site conditions.

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

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

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

iv. Implementation of a mitigation bank is subject to City Council review and approval.

i. Fee-in-lieu mitigation may be approved for use as compensation for approved impacts to wetlands, when:

ii. Fee-in-lieu mitigation may be authorized in the City based upon the following order of preference:

i. The wetland does not score six points or more for habitat in the adopted Western Washington rating system; and

ii. Are not associated with riparian areas or their buffers; and

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

iv. Are not part of a wetland mosaic; and

v. Do not contain a priority habitat or a priority area for a priority species identified by the Washington Department of Fish and Wildlife, do not contain federally listed species or their critical habitat, or species of local importance; and

vi. The buffer functions associated with the area of the reduced buffer width are mitigated through the enhancement of the wetland, the remaining on-site wetland buffer area, and/or other adjoining high value habitat areas as needed to replace lost buffer functions and values; and

vii. No subsequent buffer alteration or averaging is authorized.

i. Federally designated endangered and threatened species are those fish and wildlife species identified by the U.S. Fish and Wildlife Service and the National Marine Fisheries Service that are in danger of extinction or are threatened to become endangered. The U.S. Fish and Wildlife Service and the National Marine Fisheries Service should be consulted as necessary for current listing status;

ii. State-designated endangered, threatened, and sensitive species are those fish and wildlife species native to the coastal region of the Pacific Northwest identified by the State Department of Fish and Wildlife, that are in danger of extinction, threatened to become endangered, vulnerable, or declining and are likely to become endangered or threatened in a significant portion of their range within the state without cooperative management or removal of threats. State-designated endangered, threatened, and sensitive species are periodically recorded in WAC 232-12-014 (state endangered species), and WAC 232-12-011 (state threatened and sensitive species). The State Department of Fish and Wildlife maintains the most current listing and should be consulted as necessary for current listing status;

i. Bald eagle (Haliaeetus leucocephalus);

ii. Peregrine falcon (Falco peregrinus);

iii. Common loon (Gavia immer);

iv. Pileated woodpecker (Dryocopus pileatus);

v. Vaux’s swift (Chaetura vauxi);

vi. Merlin (Falco columbarius);

vii. Purple martin (Progne subis);

viii. Western grebe (Aechmophorus occidentalis);

ix. Great blue heron (Ardea herodias);

x. Osprey (Pandion haliaetus);

xi. Green heron (Butorides striatus);

xii. Red-tailed hawk (Buteo jamaicensis);

xiii. Western big-eared bat (Plecotus townsendii);

xiv. Keen’s myotis (Myotis keenii);

xv. Long-legged myotis (Myotis volans);

xvi. Long-eared myotis (Myotis evotis);

xvii. Townsend’s big-eared bat (Corynorhinus townsendii);

xviii. Oregon spotted frog (Rana pretiosa);

xix. Western toad (Bufo boreas);

xx. Western pond turtle (Clemmys marmorata);

xxi. Chinook salmon (Oncorhynchus tshawytscha);

xxii. Bull trout (Salvelinus confluentus);

xxiii. Coho salmon (Oncorhynchus kisutch);

xxiv. Kokanee salmon (Oncorhynchus nerka);

xxv. River lamprey (Lampetra ayresi).

i. A map prepared at an easily readable scale that includes the following:

ii. The nature and intensity of the proposed development;

iii. An analysis of mitigation sequencing as outlined in subsection M of this section;

iv. A discussion of any federal or state management recommendations, including Washington Department of Fish and Wildlife habitat management recommendations, that have been developed for species or habitats located on or adjacent to the project area;

v. An analysis of the direct and indirect potential impacts of the proposed development, activity or land use change upon the wildlife species and habitat identified for protection, including potential impacts to water quality and soil;

vi. A mitigation plan shall be provided that ensures no net loss of ecological functions and meets the following requirements:

vii. When appropriate due to the type of habitat or species present or the project area conditions, the Director may also require the habitat management plan to include an evaluation by the Washington Department of Fish and Wildlife, local Native American Indian Tribe, or other qualified professional regarding the applicant’s analysis and the effectiveness of any proposed mitigating measures or programs, to include any recommendations as appropriate; and

viii. When appropriate, information from the Washington Department of Fish and Wildlife’s Habitat at Home program shall be included.

i. The Department shall require the establishment of buffer areas for development activities in, or adjacent to, habitat conservation areas when needed to protect habitat conservation areas. Buffers shall consist of an undisturbed area of native vegetation, or areas identified for restoration, established to protect the integrity and specified season.

ii. Where applicable, a fish and wildlife habitat corridor shall be established as required in subsection W.3 of this section. A habitat conservation area may be altered only if the proposed alteration improves functions of the habitat. Required buffer widths shall consider the management recommendations identified in this section and reflect the sensitivity of the habitat and the type and intensity of human activity proposed to be conducted nearby. When a species is more susceptible to adverse impacts during specific periods of the year, seasonal restrictions may apply. Development activities may be further restricted, and buffers may be increased, if the mitigation proposed does not improve the quantitative and qualitative functions and values of the habitat, except in accordance with this chapter.

iii. In addition to the provisions of subsection E of this section, removal of any native vegetation or woody debris from the habitat conservation area may be allowed only as part of an approved habitat management plan, critical areas report, and/or alteration plan.

iv. Low impact uses and development activities which are consistent with the purpose and function of the habitat conservation area and do not detract from its integrity may be permitted within the conservation area depending on the sensitivity of the habitat area based on a study from a qualified professional. Examples of uses and development activities which may be permitted in appropriate cases include trails that are pervious, viewing platforms, stormwater management facilities such as grass-lined swales, utility easements and other similar uses and development activities; provided, that any impacts to the habitat resulting from such permitted facilities shall be fully mitigated.

v. Whenever development activities are proposed in or adjacent to a habitat conservation area with which state or federally endangered or threatened species have a primary association, such area shall be protected through the application of measures in accordance with a critical areas report prepared by a qualified professional and approved by the City of Sammamish, with guidance provided by the appropriate state and/or federal agencies.

vi. Plant, wildlife, or fish species not native to the coastal region of the Pacific Northwest shall not be introduced into habitat conservation areas unless authorized by this chapter and by any required state or federal permit or approval.

vii. Mitigation sites shall be located to achieve contiguous wildlife habitat corridors in accordance with a mitigation plan that is part of an approved critical areas report to minimize the isolating effects of development on habitat areas, so long as mitigation of aquatic habitat is located within the same aquatic ecosystem as the area disturbed.

viii. The Director shall condition approvals of development activities allowed within or adjacent to a habitat conservation area or its buffers, as necessary, to minimize or mitigate any potential adverse impacts. Conditions may include, but are not limited to, the following:

ix. Mitigation of alterations to habitat conservation areas shall achieve equivalent or greater biologic functions and shall include mitigation for adverse impacts from the proposed development as appropriate. Mitigation shall address each function affected by the alteration to achieve functional equivalency or improvement on a per-function basis.

i. Forms one contiguous tract that connects on-site high value habitat areas to other on-site or off-site high value habitat areas;

ii. New development proposals shall provide a minimum fish and wildlife habitat corridor width of 100 feet or a corridor width that is consistent with an approved habitat management plan;

iii. In addition to the provisions of subsection E of this section, development proposals on sites constrained by a fish and wildlife habitat corridor and where development already exists shall maintain a minimum fish and wildlife habitat corridor width of 100 feet unless, through an approved habitat management plan, it can be shown that a lesser habitat corridor width supports and maintains the corridor’s function and value;

iv. Be contiguous with and include and/or connect critical areas, buffers, and open space tracts or wooded areas on site or on adjacent properties, if present; and

v. The Director may modify corridor widths based on supporting documentation from an approved habitat management plan.

i. The buffer widths in the table above assume the buffer is vegetated with a native plant community appropriate for the ecoregion. If the existing buffer does not meet vegetative buffer standards, is unvegetated, sparsely vegetated, or vegetated with invasive species that do not perform needed functions, the buffer must either be densely planted to create the appropriate native plant community or be widened by 33 percent to ensure that the buffer provides adequate functions to protect the stream.

ii. Interrupted Buffer. Where a legally established and constructed street transects a stream buffer, the Department may approve a modification of the standard buffer width to the edge of the street if the isolated part of the buffer does not provide additional protection of the stream and provides insignificant biological, geological or hydrological buffer functions relating to the stream. If the resulting buffer distance is less than 50 percent of the standard buffer, no further reduction shall be allowed.

iii. Legally Established Buffer. Where a buffer has been previously established on a legally created parcel or tract that was legally established according to the regulations in place at the time of establishment and is permanently recorded on title or placed within a separate tract, and the parcels that are included on the plat at the time of recording of the subject parcel or tract, then the buffer shall remain as previously established, provided:

i. The minimum buffer required for the stream type involved or a 25-foot buffer beyond the top of the slope, whichever is greater, if the horizontal length of the slope, including small benches and terraces, is within the buffer for that stream type; or

ii. A 25-foot buffer beyond the minimum buffer width required for the stream type involved if the horizontal length of the slope, including small benches and terraces, extends beyond the buffer for that stream type.

i. It will provide additional natural resource protection as long as the total area contained in the buffer on the development proposal site does not decrease, and equivalent or greater buffer functions are provided (see also SMC 21.06.020.F.2.d for buffer compensation requirements for trails);

ii. The riparian area contains variations in sensitivity due to existing physical characteristics or the character of the buffer varies in slope, soils, or vegetation, and the stream would benefit from a wider buffer in places and would not be adversely impacted by a narrower buffer in other places;

iii. The buffer width is not reduced to less than 75 percent of the standard buffer;

iv. The buffer is associated with a development proposal, and it will not further encumber a neighboring property not owned by the applicant.

i. The development proposal has known locations of a designated fish and wildlife habitat conservation area or habitat connections for which a habitat management plan indicates that a larger buffer is necessary to protect habitat values for such species;

ii. A landslide or erosion hazard area is contiguous to a regulated stream and/or its buffer;

iii. A larger buffer is necessary to offset buffer impacts, such as trail and utility corridors; or

iv. The development is within the vicinity of at-risk ecological stream and/or riparian area functions identified in a critical areas report or habitat management plan including, but not limited to, the following:

i. No feasible alternative location is available;

ii. The utility corridor meets any additional requirements for installation, replacement of vegetation and maintenance, as needed to mitigate impacts;

iii. The requirements for sewer utility corridors in subsection V.2 of this section shall also apply to streams; and

iv. Joint use of an approved sewer utility corridor by other utilities may be allowed.

i. Surface water discharge to a stream from a flow control or water quality treatment facility, sediment pond or other surface water management activity or facility may be allowed if the discharge is in compliance with the applicable City-adopted stormwater requirements.

i. Bridges, bottomless culverts, or other appropriate methods demonstrated to provide fisheries protection shall be used for stream crossings and the applicant shall demonstrate that such methods and their implementation will pose no harm to the stream or riparian habitat or inhibit migration of anadromous fish;

ii. All crossings are constructed during the summer low flow and are timed to avoid stream disturbance during periods when use is critical to fish use;

iii. Crossings do not occur over spawning areas used by resident or anadromous fish including salmonids unless the City determines that no other feasible crossing site exists;

iv. Bridge piers or abutments are not placed within the FEMA floodway or the ordinary high water mark;

v. Crossings do not diminish the flood-carrying capacity of the stream;

vi. Underground utility crossings are laterally drilled and located at a depth of four feet below the maximum depth of scour for the base flood predicted by a civil engineer licensed by the state of Washington. Temporary bore pits to perform such crossings may be permitted within the stream buffer established in subsection W.4 of this section. Crossing of Type Ns streams when dry may be made with open cuts;

vii. Trail crossings shall use bridges and boardwalks consistent with the design requirements of the Washington Department of Fish and Wildlife (WDFW, 2013, Water Crossing Design Guidelines, as amended); and

viii. The number of crossings is minimized and consolidated to serve multiple purposes and properties whenever possible.

i. Type F, Np, and Ns streams as part of a public road, trail, or park project for which a public agency and utility exception is granted pursuant to subsection F of this section; and

ii. Type F, Np, and Ns streams for the purpose of enhancing resources in the stream if:

i. The equivalent base flood storage volume and function will be maintained;

ii. There will be no adverse impact to local groundwater;

iii. There will be no increase in velocity;

iv. There will be no interbasin transfer of water;

v. There will be no increase in sediment load;

vi. Requirements set out in the mitigation plan are met;

vii. The relocation conforms to other applicable laws; and

viii. All work will be carried out under the direct supervision of a qualified biologist.

i. Movement of the stream channel threatens existing residential or commercial structures, public facilities or improvements, unique natural resources or the only existing access to property;

ii. The stabilization is done in compliance with the requirements of subsection X of this section and Chapter 15.10 SMC and is consistent with the guidelines of the Washington State Integrated Streambank Protection Guidelines (2003, or as amended); and

iii. Soft-bank stabilization techniques are utilized unless the applicant demonstrates that soft-bank techniques are not a feasible alternative due to site-specific soil, geologic and/or hydrologic conditions.

i. The restoration is sponsored or approved by a public agency with a mandate to do such work;

ii. The restoration is unassociated with mitigation of a specific development proposal;

iii. The restoration is limited to placement of rock weirs, log controls, spawning gravel, and other specific habitat improvements for resident or anadromous fish including salmonids;

iv. The restoration only involves the use of hand labor and light equipment; or the use of helicopters and cranes that deliver supplies to the project site; provided, that they have no contact with critical areas or their buffers;

v. The restoration is performed under the direction of qualified professionals; and

vi. Stream relocation, if proposed, may be approved pursuant to subsection W.5.h of this section as part of an approved restoration plan.

vii. The City encourages opening up or daylighting piped stream segments to restore the stream to a more natural and open condition.

i. Habitat complexity, connectivity, and other biological functions;

ii. Seasonal hydrological dynamics, water storage capacity and water quality; and

iii. Geomorphic and habitat processes and functions.

i. There are no feasible on-site opportunities for mitigation or on-site opportunities do not have a high likelihood of success due to development pressures, adjacent land uses, or on-site buffers or connectivity are inadequate;

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

iii. Off-site locations have been identified and evaluated in the following order of preference:

i. A City-approved program that utilizes receiving mitigation sites within the same sub-basin as the approved wetland impact.

ii. The King County mitigation reserves program, or other approved program that gives priority to sites within the same sub-basin.

iii. A City-approved program, the King County mitigation reserves program, or other approved program that gives priority to sites that will expand or improve habitat for Lake Sammamish kokanee.

iv. The King County mitigation reserves program, or other approved program that gives priority to sites within the same sub-basin and/or a predefined service area that includes the City of Sammamish.

i. The restoration will reliably and demonstrably improve the water quality and fish and wildlife habitat of the stream;

ii. The restoration will have no lasting significant adverse impact on any stream functions; and

iii. On sites where nonnative vegetation was cleared, restoration shall include installation of native vegetation with a density equal to or greater than the prealtered site conditions.

i. Existing whole-lake total phosphorus concentration for the combined Beaver Lake system is 23 micrograms/liter. Beaver Lake 1 and Beaver Lake 2, individually, have whole-lake total phosphorus concentrations of 36 (±2) micrograms/liter and 20 (±1) micrograms/liter, respectively;