Town of Winthrop, WA Chapter 18.06 CRITICAL AREAS REGULATIONS [1]

[1] Prior legislation: Ord. 599.

§ 18.06.010 Purpose and applicability.

A. Purpose. The purpose of this title is to designate ecologically sensitive and hazardous areas and to protect these areas and their functions and values in a manner that also allows reasonable use of private property. This chapter is intended to:

1. Implement the town of Winthrop comprehensive plan (as amended) and the requirements of Chapter 36.70A RCW;

2. Protect critical areas, in accordance with Chapter 36.70A RCW and through the application of best available science, as determined according to WAC 365-195-900 through 365-195-925, and in consultation with state and federal agencies and other qualified professionals;

3. Protect the general public, resources and facilities from injury, loss of life, property damage or financial loss due to flooding, erosion, landslides, or steep slopes failure;

4. Protect unique, fragile and valuable elements of the environment, including ground and surface waters, wetlands, and fish and wildlife and their habitats, with special consideration for protection of anadromous fisheries;

5. Prevent cumulative adverse environmental impacts to water quality and availability, wetlands, and fish and wildlife habitat; and

6. Provide flexibility and attention to site specific characteristics to permit reasonable use of property.

7. Compliance with the provisions of the chapter does not constitute compliance with other federal, state, and local regulations and permit requirements that may be required (for example, shoreline substantial development permits or hydraulic project approval permits). The applicant is responsible for complying with any additional requirements, apart from the process established in this chapter.

B. Applicability. These critical area regulations shall apply as an overlay to zoning and other land use regulations established by this code (as amended).

1. All land uses and/or development permit applications on all lots or parcels within the town that lie within critical areas as defined herein shall comply with the provisions of this chapter. No action shall be taken by any person that results in any alteration of any critical area except as consistent with the purposes, objectives and intent of this chapter.

2. Where two or more types of critical areas overlap, requirements for development shall be consistent with the standards for each critical area.

3. These critical areas regulations shall apply concurrently with review conducted under the State Environmental Policy Act (SEPA), as locally adopted. Any conditions required pursuant to this chapter shall be included in the SEPA review and threshold determination.

4. Regulations for Protecting Waters of the State. The provisions of the shoreline master program apply to all shorelines of the state as defined herein. Where conflicts arise between the shoreline development regulations and critical areas regulations applicable in shoreline areas, the more restrictive will apply.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.020 Definitions.

"Administrator"

means the Winthrop town planner or other person designated by the mayor and approved by the council.

"Agency consultation"

means consultation with any state or federal agency with expertise in the best available science as it applies to critical areas within the town of Winthrop. Such agency consultation includes, but is not limited to, consultation with the Washington Department of Fish and Wildlife and/or the U. S. Fish and Wildlife Service for the purpose of making a preliminary determination regarding impacts of a development proposal on fish and wildlife habitat conservation area functions and values; consultation with the Washington Department of Ecology regarding delineation and regulation of wetlands; and/or consultation with the Washington Department of Health regarding impacts to critical aquifer recharge areas. "Agency consultation" does not mean "endangered species section 7 consultation."

"Anadromous fish"

means fish species that spend most of their life cycle in salt water, but return to freshwater to reproduce.

"Avulsion"

means a sudden abandonment of a part or the whole of a meander belt by a stream for some new course.

"Avulsion hazard zone (AHZ)"

means the portion of the CMZ that delineates avulsion hazards not accounted for in the HMZ.

"Best available science"

means current scientific information used in the process to designate, protect or restore critical areas, that is derived from a valid scientific process as defined by WAC 365-195-900 through 365-195-925.

"Buffer" or "buffer zone"

means an area contiguous to and protective of a critical area that is required for the continued maintenance, functioning, and/or structural stability of a critical area.

"Channel migration zone (CMZ)"

means those areas subject to risk from lateral channel movement due to stream bank destabilization, rapid stream channel changes (i.e., avulsions), stream bank erosion, and/or shifts in location of stream channels, as shown on Okanogan County's channel migration zone hazard maps.

"Critical aquifer recharge areas"

means those areas with a critical recharging effect on aquifers used for potable water.

"Critical areas"

include the following areas and ecosystems: critical aquifer recharge areas; fish and wildlife habitat conservation areas; flood hazard areas (including frequently flooded areas and channel migration zones); geologically hazardous areas; and wetlands.

"Development"

means any activity upon the land consisting of construction or alteration of structures, earth movement, dredging, dumping, grading, filling, mining, removal of any sand, gravel or minerals, driving of piles, drilling operations, bulkheading, clearing of vegetation, or other land disturbance. "Development" includes storage or use of equipment or materials inconsistent with the existing use. Development approvals issued by the town that bind land to specific patterns of use, including, but not limited to, subdivisions, short subdivisions, zone changes, conditional use permits and planned developments. "Development" does not include interior building improvements, exterior structure maintenance activities, routine landscape maintenance, or maintenance of individual utility service connections.

"Dwelling"

means a building or portion thereof that contains living facilities, including provisions for sleeping, eating, cooking and sanitation for not more than one family. This definition specifically excludes recreational vehicles.

"Erosion hazard zone (EHZ)"

means the area of the CMZ unaccounted for in the AHZ or the HMZ, which delineates channel susceptibility to lateral bank erosion.

"Fish and wildlife habitat conservation areas" are areas that serve a critical role in sustaining needed habitats and species for the functional integrity of the ecosystem, and which, if altered, may reduce the likelihood that the species will persist over the long term.

These areas may include, but are not limited to, rare or vulnerable ecological systems, communities, and habitat or habitat elements including seasonal ranges, breeding habitat, winter range, and movement corridors; and areas with high relative population density or species richness. "Fish and wildlife habitat conservation areas" do not include such artificial features or constructs as irrigation delivery systems, irrigation infrastructure, irrigation canals, or drainage ditches that lie within the boundaries of and are maintained by an irrigation district or company.

"Fish habitat"

means a complex of physical, chemical, and biological conditions that provide the life supporting and reproductive needs of a species or life stage of fish. Although the habitat requirements of a species depend on its age and activity, the basic components of fish habitat in rivers, streams, ponds, lakes, estuaries, marine waters, and near shore areas include, but are not limited to, the following:

1. Clean water and appropriate temperatures for spawning, rearing, and holding;

2. Adequate water depth and velocity for migrating, spawning, rearing, and holding, including off-channel habitat;

3. Abundance of bank and in-stream structures to provide hiding and resting areas and stabilize stream banks and beds;

4. Appropriate substrates for spawning and embryonic development. For stream and lake dwelling fishes, substrates range from sands and gravel to rooted vegetation or submerged rocks and logs. Generally, substrates must be relatively stable and free of silts or fine sand;

5. Presence of riparian vegetation. Riparian vegetation creates a transition zone, which provides shade, and food sources of aquatic and terrestrial insects for fish;

6. Unimpeded passage (i.e., due to suitable gradient and lack of barriers) for upstream and downstream migrating juveniles and adults.

"Flood event"

means any rise in the surface elevation of a water body to a level that causes the inundation or submersion of areas normally above the ordinary high water mark.

"Flood hazard areas"

means those areas designated in Section 18.06.170.

"Functions and values"

means beneficial roles served by critical areas; including, but not limited to, water quality protection and enhancement, fish and wildlife habitat, flood storage, conveyance and attenuation, ground water recharge and discharge, erosion control, protection from hazards, historical and archaeological and aesthetic value protection, and recreation.

"Geologically hazardous areas"

means areas that because of their susceptibility to erosion, sliding, earthquake, or other geological events, are not suited to the siting of commercial, residential, or industrial development consistent with public health or safety concerns.

"Low impact development (LID)"

is a stormwater and land use management strategy that strives to mimic predisturbance hydrologic processes of infiltration, filtration, storage, evaporation and transpiration by emphasizing conservation, use of on-site natural features, site planning, and distributed stormwater management practices that are integrated into a project design.

"Priority habitat"

means a habitat type or element designated as priority habitat by the Washington Department of Fish and Wildlife.

"Qualified professional"

means a person with experience and training in the pertinent scientific discipline. A qualified professional must have obtained a B.S. or B.A. or equivalent degree in biology, engineering, environmental studies, fisheries, geomorphology or related field, and two years of related work experience. A qualified professional for habitat must have a degree in biology and professional experience related to the subject species. A qualified professional for wetlands must be a professional wetland scientist with at least two years of full-time work experience as a wetlands professional, including delineating wetlands using the state or federal manuals, preparing wetland reports, conducting function assessments, and developing and implementing mitigation plans. A qualified professional for geological hazards must be a professional engineer or geologist, licensed in the state of Washington. A qualified professional for critical aquifer recharge areas must be a state-licensed hydrogeologist, geologist, engineer, or other scientist with experience in preparing hydrogeologic assessments.

"Resident fish species"

means a fish species that completes all stages of its life cycle within freshwater and frequently within a local area.

"River-reach scale"

means the scope of engineering assessments addressing erosion and/or scour problems shall incorporate potential impacts that may extend both up- and downstream of the project site, and not only be limited to the project site boundaries. The term "reach" refers to a segment of the river that exhibits similar hydrologic, hydraulic, and/or fluvial geomorphic characteristics. It is assumed that a river reach will therefore exhibit similar and/or linked fluvial geomorphic characteristics in response to changes that may be implemented within the boundaries of the defined reach.

"Wellhead protection area"

means the portion of a well's, wellfield's, or spring's zone of contribution within the ten (10) year time of travel boundary, or boundaries established using alternate criteria approved by the State Department of Health in those settings where groundwater time of travel is not a reasonable delineation criteria.

"Wetland" or "wetlands"

means areas that are inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. "Wetlands" generally include swamps, marshes, bogs, and similar areas. "Wetlands" do not include those artificial wetlands intentionally created from nonwetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands created after July 1, 1990, that were unintentionally created as a result of the construction of a road, street, or highway. "Wetlands" may include those artificial wetlands intentionally created from nonwetland areas to mitigate conversion of wetlands.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.030 Exemptions.

The activities listed below are exempt from the provisions of this chapter. Exempt activities shall be conducted using all reasonable methods to avoid impacts to critical areas. Exemption from the chapter shall not be considered permission to degrade a critical area or ignore risks from natural hazards. Incidental damage to, or alteration of, a critical area that is not a necessary outcome of the exempted activity shall be restored and rehabilitated at the responsible party's expense.

A. Emergency construction necessary to protect life or property from immediate damage by the elements. An "emergency" is an unanticipated event or occurrence which poses an imminent threat to public health, safety, or the environment, and which requires immediate action within a time too short to allow full compliance. Once the threat to the public health, safety, or the environment has dissipated, the construction undertaken as a result of the previous emergency shall then be subject to and brought into full compliance with this title;

B. Normal maintenance or repair of existing buildings, structures, roads, utilities, levees, or drainage systems, provided the activity does not further alter, encroach upon, or increase impacts to critical areas or associated buffers;

C. Existing agricultural activities normal or necessary to general farming conducted according to industry-recognized best management practices, including the raising of crops or the grazing of livestock;

D. Site investigative work necessary for land use application submittals such as surveys, soil logs, percolation tests and other related activities. In every case, critical area impacts shall be minimized and disturbed areas shall be immediately restored; and

E. Passive recreational activities, including, but not limited to: fishing, bird watching, hiking, hunting, boating, horseback riding, skiing, swimming, canoeing, and bicycling, provided the activity does not alter the critical area or its buffer by changing existing topography, water conditions or water sources.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.040 Public agency and utility exception.

A. If application of this title would prohibit a development proposal by a public agency or public utility, the agency or utility may apply for an exception pursuant to this section. To qualify for an exception the agency or utility must demonstrate the following:

1. That there is no other practical alternative to the proposed development which has less impact on critical areas;

2. The application of this title would unreasonably restrict the ability to provide utility services to the public;

3. That the proposed use does not pose a threat to the public health, safety or welfare;

4. That the proposal protects critical areas functions and values to the extent feasible and provides for mitigation in accord with the provisions of this title; and

5. The proposal is consistent with other applicable regulations and standards.

B. A request for exception shall be submitted to the town with the application materials for the particular development proposal. The application shall be supplemented with an explanation as to how the public agency and utility exception criteria are satisfied. The administrator may require additional information or studies to supplement the exception request.

C. A public agency and utility exception shall be processed according to the provisions of Title 19, Administrative Procedures, governing a Type I review process.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.050 Reasonable use exception.

A. If the application of this title would deny all reasonable use of the subject property, the property owner may apply for an exception pursuant to this section. To qualify for an exception the applicant must demonstrate all of the following:

1. That no other reasonable use can be made of the property that will have a lesser adverse impact on the critical area and adjoining and neighboring lands;

2. That the proposed use does not pose a threat to the public health, safety or welfare;

3. Any alteration is the minimum necessary to allow reasonable use of the property; and

4. The inability of the proponent to derive reasonable use of the property is not the result of actions by the applicant after the effective date of this chapter.

B. A request for a reasonable use exception shall be submitted to the town with the application materials for the particular development proposal. The application shall be supplemented with an explanation as to how the reasonable use exception criteria are satisfied. The town may require additional information or studies to supplement the reasonable use exception request.

C. Where a request for a reasonable use exception is granted, impacts to critical areas and buffers shall be mitigated consistent with the purpose and standards of this chapter to the greatest extent feasible.

D. A reasonable use exception shall be processed according to the provisions of Title 19, Administrative Procedures, governing a Type I review process.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.060 Reference maps and materials.

The town shall maintain reference maps and materials that provide information on the general locations of critical areas. Since boundaries are generalized, the application of this chapter and the actual type, extent and boundaries of critical areas shall be determined and governed by the classification section established for each critical area. In the event of any conflict between the critical area location or designation shown on the town's maps and the criteria and standards established in this chapter, or the site-specific conditions, the criteria, standards and/or site-specific conditions shall prevail. Reference maps and inventories shall include, but are not limited to the following (or, where applicable, any subsequent or amended version):

A. Town of Winthrop comprehensive plan;

B. Town of Winthrop shoreline master program;

C. Town of Winthrop comprehensive flood hazard management plan;

D. Town of Winthrop water system plan and wellhead protection area;

E. Wetlands map, based upon the U.S. Fish and Wildlife Service National Wetlands Inventory;

F. Fish and wildlife habitat area maps, based upon the Washington Department of Fish and Wildlife priority habitats and species data;

G. NRCS hydrologic soils group mapping;

H. Flood Insurance Rate Map Community 530124B, Panel H&I-01, 1977; Community 530117, Panels 0675D and 0850C (as amended);

I. U.S. Army Corps of Engineers Wetland Delineation Manual, 1987, or as amended, arid west regional supplement;

J. Washington State Wetlands Rating System for Eastern Washington (Department of Ecology Publication No. 4-06-15), as revised;

K. Wetlands in Washington State, Volumes 1 and 2: Managing and Protecting Wetlands (Department of Ecology Publications Nos. 05-06-006 and 05-06-008);

L. Washington State Department of Health Source Water Assessment Program (SWAP) mapping application at https://fortress.wa.gov/doh/swap/index.html (wellhead protection areas);

M. Approved critical areas reports, special studies, geotechnical analyses, and other special reports previously completed for a subject property;

N. Monitoring data.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.070 Critical areas review process.

A. Dislosure of Activities. All land use and building permits and business licenses shall require that applicants disclose development activities as follows:

1. Activities with the potential to contaminate groundwater or inhibit aquifer recharge on lands within the town limits.

2. Activities within one hundred (100) feet of known or suspected fish and wildlife habitat areas and geologically hazardous areas. Indications of these types of critical areas could include, but are not limited to, undeveloped lands with native vegetation and steep slopes.

3. Activities within two hundred (200) feet of wetlands or water bodies.

4. Where the known or suspected critical area is a fish and wildlife habitat conservation area and a plan or agreement for the habitat or species in question has been prepared and approved by the Washington Department of Fish and Wildlife (WDFW) and the town of Winthrop, the provisions of said plan or agreement shall take precedence over the provisions of this critical areas review process. If, based on the provisions of such a plan or agreement, the requirements of any part of the critical areas review process have been waived, all relevant land use/development applications and, where applicable, a SEPA checklist, shall be required.

B. Preapplication Meeting/Site Visit. Upon receiving a land use or development proposal, the administrator shall schedule a preapplication meeting and/or site visit with the proponent for purposes of a preliminary determination whether the proposal is likely to result in impacts to the functions and values of critical areas or pose health and safety hazards. At this meeting, the administrator shall discuss the requirements of this chapter and other applicable local regulations; provide critical areas maps and other available reference materials; outline the review and permitting processes; and work with the proponent to identify any potential concerns with regards to critical areas. If the administrator determines there are no critical areas present or that proposed development does not impact critical areas, no further action is required.

C. Agency Consultation. Agency consultation shall be required where activities are proposed within one hundred (100) feet of a designated fish and wildlife habitat conservation area or two hundred (200) feet of wetlands. The administrator shall initiate agency consultation to determine the value of the site to federal or state identified endangered, threatened, sensitive, or candidate species; animal aggregations considered vulnerable by the WDFW; and those species of recreational, commercial, or tribal importance that are considered vulnerable by the WDFW. The administrator shall consult with the WDFW to determine whether the proposed action may affect priority habitat, and shall consult with the Washington Department of Ecology when development falls within 200 feet of known or potential wetlands. The administrator may utilize agency consultation in consideration of proposed activity within critical aquifer recharge areas, flood hazard areas, or geologic hazard areas.

D. Application and SEPA Checklist. For all nonexempt proposals where the administrator has determined critical areas may be present or impacted, the proponent shall submit all relevant land use/development applications, together with a SEPA checklist. The administrator may waive the requirement for a SEPA checklist if the proposal is categorically exempt under SEPA regulations.

E. Determination of Need for a Critical Areas Report. Based upon the preapplication meeting, application materials, SEPA checklist, and the outcome of the agency consultation, the administrator shall determine if there is cause to require a critical areas report, hydrogeological assessment, and/or geotechnical report. In addition, the administrator may use critical areas maps and reference materials, information and scientific opinions from appropriate agencies, or any reasonable evidence regarding the existence of critical area(s) on or within one hundred (100) feet of the site of the proposed activity or within two hundred (200) feet of wetlands.

F. Review of Documentation. The administrator may retain professional consultant services for the review of critical areas reports and associated application materials. Applicants shall reimburse the town for all such costs at the same rate that is paid by the town, as established by the town's fee resolution (as revised or amended).

G. Documentation and Notification. The administrator shall document the preapplication meeting and/or site visit, agency consultation, application and SEPA threshold determination, and any other steps or findings that inform the determination whether a critical areas report shall be required. The applicant shall receive notice of the determination and any findings which support it.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.080 Critical areas report.

If the administrator determines that the site of a proposed development potentially includes, or is adjacent to, critical area(s), a critical areas report may be required. When required, the expense of preparing the critical areas report shall be borne by the applicant. The content, format and extent of the critical areas report shall be approved by the administrator.

A. The requirement for critical areas reports may be waived by the administrator if there is substantial evidence that:

1. There will be no alteration of the critical area(s) and/or the required buffer(s);

2. The proposal will not impact the critical area(s) in a manner contrary to the purpose, intent and requirements of this chapter and the comprehensive plan; and

3. The minimum standards of this chapter will be met.

B. No critical areas report is required for proposals that are exempt from the provisions of this chapter as set forth under Section 18.06.030, Exemptions.

C. Critical area reports shall be completed by a qualified professional who is knowledgeable about the specific critical area(s) in question and approved by the administrator.

D. At a minimum, a required critical areas report shall contain the following information:

1. Applicant's name and contact information; permits being sought; and description of the proposal;

2. A copy of the site plan for the development proposal, drawn to scale and showing:

a. Identified critical areas, buffers where applicable, and the development proposal with dimensions;

b. Limits of any areas to be cleared; and

c. A description of the proposed stormwater management plan for the development and consideration of impacts to drainage alterations;

3. The names and qualifications of the persons preparing the report and documentation of any fieldwork performed on the site;

4. Identification and characterization of all critical areas, wetlands, water bodies, and buffers on or adjacent to the proposed project area;

5. An assessment of the probable cumulative impacts to critical areas resulting from the proposed development of the site;

6. An analysis of site development alternatives;

7. A description of reasonable efforts made to apply mitigation sequencing to avoid, minimize, and mitigate impacts to wetlands, geohazard areas or fish and wildlife habitat areas;

8. A mitigation plan, as applicable, in accordance with the mitigation requirements of this chapter, including, but not limited to:

a. The impacts of any proposed development within or adjacent to a critical area or buffer on the critical area; and

b. The impacts of any proposed alteration of a critical area or buffer on the development proposal, other properties and the environment;

9. A discussion of the performance standards applicable to the critical area and proposed activity;

10. Additional requirements for wetlands, as detailed in Section 18.06.160(G);

11. Geotechnical reports and/or hydrogeologic assessments, as required to assess impacts of development within critical aquifer recharge areas or geologically hazardous areas;

12. Financial guarantees to ensure compliance; and

13. Any additional information required for specific critical areas as listed in subsequent sections of this chapter.

E. The administrator may request any other information reasonably deemed necessary to understand impacts to critical areas.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.085 Geotechnical reports.

If the administrator determines that the site of a proposed development potentially includes or is adjacent to geological hazard areas, a geotechnical report may be required. When required the expense of preparing the geotechnical report shall be borne by the applicant. Geotechnical reports shall be completed by a qualified professional approved by the administrator. Geotechnical reports shall contain description of the geology of the site, conclusions and recommendations regarding the effect of geologic conditions on the proposed development, and opinions and recommendations on the suitability of the site to be developed. More specifically, the report shall evaluate the actual presence of geologic conditions giving rise to the geologic hazard, including without limitation the following:

A. Documentation of site history, evidence of past geologically hazardous activities in the vicinity, quantitative analysis of slope stability and available geologic information;

B. Surface reconnaissance of the site and adjacent areas;

C. Subsurface exploration of the site to assess potential geologic impacts of the proposal;

D. Hydrologic analysis of slope and/or soil stability;

E. Approximate depth to groundwater;

F. Evaluation of the safety of the proposed project, and identification of construction practices, monitoring programs and other mitigation measures necessary; and

G. Demonstration of the following:

1. There will be no increase in surface water discharge or sedimentation to adjacent properties;

2. There will be no decrease in slope stability on the site nor on adjacent properties;

3. There is no hazard as proven by evidence of no past geologically hazardous activity in the vicinity of the proposed development and a quantitative analysis of slope stability indicates no significant risk to the development proposal and adjacent properties; and

4. The geologically hazardous area can be modified or the development proposal can be designed such that the hazard is eliminated or mitigated, making the site as safe as one without a hazard.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.090 Mitigation requirements.

The applicant shall avoid all impacts that degrade the functions and values of critical areas. If alteration of wetlands, fish and wildlife habitat areas, or geohazard areas is unavoidable, all adverse impacts to these three types of critical areas and buffers resulting from the proposal shall be mitigated in accordance with an approved critical areas report and SEPA documents. Mitigation shall be on site, when possible, and sufficient to maintain the functions and values of the critical area, and to prevent risk from a hazard posed by a critical area.

A. Mitigation Sequencing. Applicants shall demonstrate that all reasonable efforts have been examined with the intent to avoid and minimize impacts to critical areas. When an alteration to a critical area is proposed, such alteration shall be avoided, minimized, or compensated for in the following order of preference:

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

2. Minimizing impacts by limiting the degree or magnitude of the action and its implementation, by using appropriate technology, or by taking affirmative steps, such as project redesign, relocation, or timing, to avoid or reduce impacts;

3. Rectifying the impact to wetlands and habitat conservation areas by repairing, rehabilitating, or restoring the affected environment to the historical conditions or the conditions existing at the time of the initiation of the project;

4. Minimizing or eliminating the hazard by restoring or stabilizing the hazard area through engineered or other methods;

5. Reducing or eliminating the impact or hazard over time by preservation and maintenance operations during the life of the action;

6. Compensating for the impact to wetlands and habitat conservation areas by replacing, enhancing, or providing substitute resources or environments; and

7. Monitoring the hazard or other required mitigation and taking remedial action when necessary.

B. Mitigation Plan. When mitigation is required, the applicant shall submit for approval a mitigation plan as part of the critical area report. Approval of a mitigation plan is subject to Section 18.06.070(F). The mitigation plan shall include:

1. A written report identifying mitigation objectives, including:

a. A description of the anticipated impacts to the critical areas and the mitigating actions proposed and the purposes of the compensation measures, including the site selection criteria; identification of compensation objectives; identification of critical area functions and values; and dates for beginning and completion of site compensation construction activities;

b. A review of the best available science supporting the proposed mitigation and a description of the report author's experience to date in critical areas mitigation; and

c. An analysis of the likelihood of success of the compensation project.

2. Measurable criteria for evaluating whether or not the objectives of the mitigation plan have been successfully attained and whether or not the requirements of this chapter have been met.

3. Written specifications and descriptions of the mitigation proposed, including, but not limited to:

a. The proposed construction sequence, timing, and duration;

b. Grading and excavation details;

c. Erosion and sediment control features;

d. A planting plan specifying plant species, quantities, locations, size, spacing, and density; and

e. Measures to protect and maintain plants until established.

4. A program for monitoring construction of the compensation project, and for assessing the completed project and its effectiveness over time. The program shall include a schedule for site monitoring and methods to be used in evaluating whether performance standards are being met. A monitoring report shall be submitted as needed to document milestones, successes, problems, and contingency actions of the compensation project. The compensation project shall be monitored for a period necessary to establish that performance standards have been met, but not for a period less than five years from the date of planting, or ten (10) years where establishment of woody vegetation is the intended result. Where a ten (10) year monitoring program is required, data collection and reporting need not be completed every year. A monitoring schedule based on the findings of the critical areas report and adequate to effectively monitor canopy development shall be established in the mitigation plan.

5. Identify potential courses of action, and any corrective measures to be taken if monitoring or evaluation indicates project performance standards are not being met.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.100 General development standards.

In addition to the development standards specific to each type of critical area, the following standards shall apply:

A. Stormwater and Drainage. All development, including subdivision of land, where critical areas are identified shall be required to address stormwater and drainage, including snow removal, in accord with the following standards:

1. Stormwater and drainage shall be collected, retained, and disposed of on site.

2. Impervious lot coverage shall be minimized to the extent necessary to provide protection and/or mitigation from impacts to critical areas in accord with best available science and the standards contained in this chapter.

3. For land use and development applications that require a stormwater and drainage plan, such plans shall be prepared by a qualified professional engineer and shall conform to the guidelines and standards set forth in the August 2019 or latest edition of the Department of Ecology Stormwater Manual for Eastern Washington. Development may not proceed without approval of stormwater and drainage plans by the public works superintendent. Stormwater and drainage plans shall address anticipated impacts of the proposed use and the findings of a critical areas report, mitigation plan, or land use permit review.

4. Where there is potential for erosion or landslide, plans shall address methods to contain soil within the project boundaries. Best management practices (BMPs) shall be used to prevent sediment, oil, gas, pesticides or pesticide-contaminated soils, or other pollutants from entering surface or groundwater.

5. The administrator may require a separate grading and excavation plan if deemed necessary.

6. Final development approval shall not be granted until all stormwater and drainage plans are fully implemented and approved by the administrator or public works superintendent.

B. Vegetation Management and Clearing. Clearing and removal of native and/or riparian vegetation within fish and wildlife habitat areas or wetlands and associated buffers is prohibited except as authorized under this chapter through a critical areas review, report, or mitigation plans.

C. Subdivision, Planned Developments and Binding Site Plans.

1. All proposals resulting in creation of new lots shall illustrate the presence of a building site on each lot, including access, that is not located within a critical area or associated buffer and which meets all applicable standards for development within its zone. (Does not apply to critical aquifer recharge areas.)

2. All designated critical areas and associated buffers shall be clearly identified on all final plats, plans, and documents. Where applicable, such critical areas and buffers shall be identified as open space or common area, with ownership and control transferred to a homeowners' association. Alternately, such critical areas and buffers may be legally defined under an easement or covenant encumbering the property.

D. Trails and Recreation. Construction of public and private trails and related recreation facilities, such as picnic tables, benches, interpretive signs, and viewing platforms may be authorized within designated critical areas and associated buffers, subject to the following standards:

1. To the extent feasible trails and recreation facilities shall be placed within areas that have been previously developed or otherwise disturbed.

2. Trails and recreation facilities shall be sited to minimize the removal of native vegetation, particularly where such vegetation is of high value for habitat.

3. To the extent feasible, trails and related recreation facilities shall be constructed with materials that are sustainable and blend in with the surrounding environment.

E. Utilities. Construction of utilities shall be planned to minimize impacts to critical aquifer recharge areas. Construction of utilities may be authorized within wetlands, habitat conservation areas, flood hazard areas, and geologically hazardous areas where no practical alternative exists. Existing utility corridors may be maintained. The following standards shall apply to maintenance or construction of utilities:

1. Utility corridors shall be constructed and/or maintained in a manner that minimizes the disturbance to native vegetation and shall revegetate following the completion of construction activities. Safe access along utility corridors may be maintained as needed.

2. Best management practices (BMPs) shall be used to prevent sediment, oil, gas, pesticides or pesticide-contaminated soils, or other pollutants from entering surface or groundwater.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.110 Surety/bonding.

If a development proposal is subject to mitigation, maintenance or monitoring plans, the town of Winthrop, in a form acceptable to the town attorney, may require an assurance device or surety.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.120 Permit conditions.

Through the review process, the town of Winthrop shall have the authority to attach such conditions to the granting of any approval under this chapter as deemed necessary to alleviate adverse impacts to critical area(s) and to carry out the provisions of this chapter. Such conditions of approval may include, but are not limited to the following:

A. Specification of allowable lot sizes;

B. Provisions for additional buffers relative to the intensity of a use or activity;

C. Requirements and/or restrictions on the construction, size, location, bulk and/or height, etc., of structure(s);

D. Dedication of necessary easements for utilities, conservation, open space, etc.;

E. Imposition of easement agreements, sureties, deed restrictions, covenants, etc., on the future use and/or division of land;

F. Limitations on the removal of existing vegetation;

G. Limitations on impervious lot coverage;

H. Additional measures to address issues such as erosion control, stormwater management, filling, grading, etc.;

I. Development of a mitigation plan to create, enhance, or restore damaged or degraded critical area(s) on and/or off site; and

J. Any monitoring and/or maintenance plans necessary to implement the provisions of this chapter.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.130 Enforcement.

Violation of the provisions of this chapter, or failure to comply with any of its requirements, shall be subject to enforcement actions by the town of Winthrop that are authorized in the zoning ordinance of the town of Winthrop, Chapter 17.36 as amended, the subdivision ordinance, shoreline master program or any other land use regulation of the town of Winthrop. The town attorney, when authorized by the mayor and council, shall seek penalties, remedies, injunctions and other legal sanctions necessary for the enforcement of this title. In addition to costs allowed by these regulations, the prevailing party in an enforcement action may, at the court's discretion, be allowed interest and reasonable attorney's fees. The town attorney shall seek such costs, interest, and the reasonable attorney's fees on behalf of the town of Winthrop when the town is the party.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.140 Critical aquifer recharge areas.

A. Classification. Aquifer recharge areas are classified based on the susceptibility of groundwater to contamination. High potential for vulnerability is indicated by a combination of highly permeable soils and land uses that contribute directly or indirectly to contamination of groundwater. Classification of critical aquifer recharge areas is based upon NRCS hydrologic soils group mapping and the town of Winthrop's wellhead protection area. Group A soils with high permeability indicate a high potential for aquifer recharge.

B. Designation. Areas with high potential are designated as critical aquifer recharge areas:

1. High Potential. Areas characterized by Group A soils on NRCS hydrologic soils group map and areas within the wellhead protection area.

2. Low – Moderate Potential. Areas characterized by Group B, C or D soils on NRCS hydrologic soils group map. Areas with low to moderate potential not designated as critical aquifer recharge areas unless they coincide with the wellhead protection area.

C. Standards. In addition to the general provisions of this chapter and the requirements of the underlying zone, the following minimum standards shall apply to development activities within and adjacent to critical aquifer recharge areas:

1. Development activities within a critical aquifer recharge area shall be designed, planned and undertaken in a manner that will not potentially degrade groundwater resources nor adversely affect the recharging of the aquifer.

2. A hydrogeologic study and/or ongoing monitoring may be required to assess impacts of development activities on groundwater resources.

3. On-site stormwater facilities shall be designed and installed in critical aquifer recharge areas so as to provide both detention and treatment of all runoff associated with the development. Stormwater plans (where required) and implementation of those plans shall conform to all applicable standards of the August 2019 or latest edition of the Department of Ecology Stormwater Manual for Eastern Washington.

4. Landfills, junkyards/salvage yards, mining, wood treatment facilities, or any other activity which could impair aquifer recharge shall be prohibited in areas with critical recharge potential; such activities may be permitted in areas with low or moderate susceptibility, in accord with applicable zoning regulations, providing the applicant can satisfactorily demonstrate that potential negative impacts to groundwater can be prevented.

5. All storage tanks, whether above or underground, must be constructed so as to be protected against corrosion for the operational life of the tank; to prevent any release of hazardous substances to the ground, groundwaters, or surfacewaters; and to utilize appropriate containment methods.

6. Any agricultural activities conducted within critical aquifer recharge areas shall incorporate best management practices concerning waste disposal, fertilizer/pesticide/herbicide use, and stream corridor management. If necessary, applicants shall seek technical assistance from Natural Resource Conservation Service, the Okanogan County Conservation District or the WSU Cooperative Extension Office.

7. Application of pesticides, herbicides and fertilizers within critical aquifer recharge areas should be minimized, to the greatest extent possible. If deemed necessary, such use, at a minimum, shall comply with timing and rates specified on product packaging, with measures taken to avoid contamination of surface or ground waters.

8. Vehicle repair and servicing activities must be conducted over impermeable pads 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.

9. Car washes, if permitted by zoning, shall comply with the Department of Ecology's Best Management Practices for Vehicle and Equipment Washwater Discharge/Best Practices Manual (as hereinafter amended).

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.150 Fish and wildlife habitat conservation areas.

A. Designation. For purposes of this chapter, fish and wildlife habitat conservation areas shall include all of the following:

1. Those areas that provide habitats for species within the Washington State Department of Fish and Wildlife (WDFW) priority habitats and species recommendations as follows:

a. Endangered species listed at WAC 232-12-014;

b. Threatened species listed at WAC 232-12-001;

c. Sensitive species listed at WAC 232-12-011;

d. Bald eagle habitat pursuant to WAC 232-12-292;

e. Endangered or threatened species listed in accordance with the federal Endangered Species Act together with the areas with which they have a primary association;

2. Water Bodies. Streams shall be designated in accordance with the Washington State Department of Natural Resources (DNR) stream type as provided in WAC 222-16-030 with the following provisions:

a. Type S Water. All waters, within their bankfull width, as inventoried as "shorelines of the state" under Chapter 90.58 RCW and the rules promulgated pursuant to Chapter 90.58 RCW, including periodically inundated areas of their associated wetlands. Within Winthrop, the Methow and Chewuch Rivers are designated as shorelines of the state.

b. Type F-A Water. Segments of natural waters, other than Type S waters, which are within defined channels greater than ten (10) feet in width, as defined by the OHWM and periodically inundated areas of their associated wetlands or within lakes, ponds, or impoundments having a surface area of one-half acre or greater at seasonal low water and which in any case contain fish habitat. There are no known Type F-A waters in the town of Winthrop.

c. Type F-B Water. Segments of natural waters, other than Type S waters, which are within defined channels less than ten (10) feet in width, as defined by the OHWM, or within lakes, ponds, or impoundments having a surface area of less than one-half acre at seasonal low water and which in any case contain fish habitat. There are no known Type F-B waters in Winthrop.

d. Type Np Water. All segments of natural waters within defined channels that are perennial nonfish habitat streams. Perennial streams are waters that do not go dry any time of a year of normal rainfall. However, for the purpose of water typing, Type Np waters include the intermittent dry portions of the perennial channel below the uppermost point of perennial flow. There are no known Type Np waters in Winthrop.

e. Type Ns Water. All segments of natural waters within defined channels that are not Type S, F, or Np waters. These are seasonal, nonfish habitat streams in which surface flow is not present for at least some portion of a year of normal rainfall and are not located downstream from any stream reach that is a Type Np water. Ns waters must be physically connected by an aboveground channel system to Type S, F, or Np waters. There are no known Type Ns waters in Winthrop.

B. Nonfish habitat streams are those streams that have no known or potential use by anadromous or resident fish based on the stream character, hydrology and gradient; provided, that human-made barriers shall not be considered a limit on fish use except when the director makes the following findings:

1. The human-made barrier is located beneath public infrastructure that is unlikely to be replaced and it is not feasible to remove the barrier without removing the public infrastructure; provided, that the infrastructure is not identified for future modification in the capital facility or other plans of the public agency responsible for the infrastructure, and the facility will not exceed its design life within the foreseeable future;

2. The human-made barrier is located beneath one or more occupied structures and it is not feasible to remove the barrier without removing the structure, and the structure is of a size and condition that removal or substantial remodel is not likely. There are no known nonfish habitat streams in Winthrop.

C. Classification. The town shall use two general classifications of fish and wildlife habitat conservation areas. These classifications are not intended to prioritize protection of one class of habitat over the other, but to recognize that the two types of habitat areas have differing functions and values within the urban environment. In reviewing development proposals the town shall consider the fish and wildlife habitat conservation areas classification in establishing buffer widths, mitigation requirements, and permit conditions. Any decision regarding establishment of buffers, buffer widths, access restrictions, vegetation conservation and restoration requirements, mitigation requirements, or permit conditions shall be subject to agency review under Section 18.06.040.

1. Water Bodies and Riparian Habitat Conservation Areas. With this classification, the town recognizes that water bodies and riparian habitat within the town limits and urban growth area coincide with the shoreline areas of the Methow and Chewuch Rivers, flood hazard areas, wetlands and critical aquifer recharge areas. Water bodies and riparian areas offer essential habitat to a diverse array of fish and wildlife species. Best available science indicates that these areas are especially sensitive to pressures from urban development, and that they provide important habitat functions and values for many species, including anadromous fish species. Water bodies and riparian habitat conservation areas are also subject to Winthrop's shoreline master program.

2. Upland Habitat Conservation Areas. With this classification, the town recognizes that those upland areas within the defined town limits and urban growth boundary that are not otherwise designated as critical areas are frequently the most suited for human development. Upland habitats that support federal or state identified endangered, threatened or sensitive species, or any habitats which are identified as providing a high level of functions and values, must be protected in accord with federal and state regulations. However, in considering best available science, this classification also is intended to ensure that development is not subject to burdensome regulation in those areas most suited to support it. Upland habitat areas shall not include those portions of the town and urban growth area where a development pattern is already established such that connectivity of habitat has already been broken and protection of identified habitat areas is unlikely to provide measurable benefit to any of the priority species identified by WDFW.

D. Mapping. Priority habitat and species maps used by the WDFW depict general locations of fish and wildlife habitat conservation areas. However, because species populations and habitat systems are dynamic, agency consultation shall be required to verify designation as a habitat conservation area, except in cases in which a plan or agreement for the habitat or species in question has been prepared and approved by the WDFW and the town of Winthrop.

E. Standards. In addition to the general provisions of this chapter and the requirements of the underlying zone, the following minimum standards shall apply to development activities within and adjacent to fish and wildlife habitat conservation areas:

1. Habitat Assessment. Critical area reports for fish and wildlife habitat conservation areas shall include a habitat assessment to evaluate the presence or absence of a priority species or habitat.

2. All projects shall comply with the applicable federal, state and local regulations regarding the species and habitats identified upon a site.

3. The Washington State Department of Fish and Wildlife priority habitat and species management recommendations shall be consulted in developing specific measures to protect a specific project site.

4. When needed to protect the functions and values of fish and wildlife habitat conservation areas, the administrator shall require the establishment of buffer areas for activities in or adjacent to such areas. Buffers shall consist of an undisturbed area of native vegetation, or areas identified for restoration. Buffer widths shall reflect the classification and sensitivity of the habitat and the intensity of activity proposed, and shall be consistent with the management recommendations issued by the state Department of Fish and Wildlife or other best available science.

5. Any approved alteration or development shall be required to minimize impacts to native vegetation. Where disturbance is unavoidable, the applicant shall restore the area to the extent possible using native plants appropriate to the site. New plantings shall be monitored and maintained in good growing condition and kept free of invasive weeds until well established upon the site.

6. Within riparian habitat conservation areas, native vegetation shall be retained unless no other alternative exists. In such cases clearing shall be limited to those areas necessary and disturbed areas shall be replanted with site-appropriate native riparian vegetation. Vegetation planted to mitigate the removal of existing native vegetation shall be maintained and monitored for three years from planting to ensure a minimum of eighty (80) percent survival.

7. Access to fish and wildlife habitat conservation areas or buffers may be restricted in accord with the findings of a critical areas report, mitigation report, PHS management recommendations or other best available science. Access restrictions may include fencing and signs, as needed to ensure protection of habitat functions and values. Restrictions may be seasonal in nature.

8. Subdivision of lands within habitat conservation areas shall be subject to the following:

a. All division of land shall be accomplished by planned development when a threatened or endangered species is verified to be present;

b. All division of land shall be accomplished by planned development when twenty-five (25) percent or more of the site falls within one or more designated fish and wildlife conservation areas.

9. All activities, uses and alterations proposed to be located in or adjacent to water bodies used by anadromous fish shall give special consideration to the preservation and enhancement of associated habitats.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.160 Wetlands.

A. Identification and Delineation. Identification of wetlands and delineation of their boundaries pursuant to this chapter shall be done in accordance with the approved federal wetland delineation manual and applicable regional supplements. All areas within the town meeting the wetland designation criteria in that procedure are hereby designated critical areas and are subject to the provisions of this chapter. Wetland delineations are valid for five years; after such date the town shall determine whether a revision or additional assessment is necessary. The town may use National Wetlands Inventory maps as a preliminary indication of the presence of wetlands, but on-site identification and delineation shall be required for any development in proximity to wetlands.

B. Rating. Wetlands shall be rated according to the Washington Department of Ecology wetland rating system, as set forth in the Washington State Wetland Rating System for Eastern Washington: 2014 Update (Ecology Publication No. 14-06-030, or as revised and approved by Ecology), which contains the definitions and methods for determining whether the criteria below are met:

1. Category I wetlands are: alkali wetlands; wetlands of high conservation value that are identified by scientists of the Washington Natural Heritage Program/DNR; bogs and calcareous fens; mature and old-growth forested wetlands over one-fourth acre with slow-growing trees; forests with stands of aspen; and wetlands that perform many functions very well (scores between twenty-two (22) through twenty-seven (27) points). These are wetlands that represent a unique or rare wetland type; are more sensitive to disturbance than most wetlands; are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or provide a high level of function.

2. Category II wetlands are: forested wetlands in the floodplains of rivers; mature and old-growth forested wetlands over one-fourth acre with fast-growing trees; vernal pools; and wetlands that perform functions well (scores between nineteen (19) through twenty-one (21) points). These 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.

3. Category III wetlands have a moderate level of functions (scores between sixteen (16) through eighteen (18) points). These wetlands can be often adequately replaced with a well-planned mitigation project. Wetlands scoring between sixteen (16) through eighteen (18) points 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.

4. Category IV wetlands have the lowest level of functions (scores fewer than sixteen (16) points) and are often heavily disturbed. These are wetlands that we should be able to replace, and in some cases be able to improve. 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.

C. Illegal Modifications. Wetland rating categories shall not change due to illegal modifications made by the applicant or with the applicant's knowledge.

D. Regulated Activities. A critical area report is required to support the following regulated activities when they occur in a wetland or its buffer:

1. Removal, excavation, grading, or dredging of soil, sand, gravel, minerals, organic matter, or material of any kind.

2. Dumping of, discharging of, or filling with any material.

3. Draining, flooding, or disturbing the water level or water table.

4. Pile driving.

5. Construction, reconstruction, demolition, or expansion of any structure.

6. Destruction or alteration of wetland vegetation through clearing, harvesting, shading, intentional burning, or planting of vegetation that would alter the character of a regulated wetland.

7. Activities that result in:

a. A significant change of water temperature.

b. A significant change of physical or chemical characteristics of the sources of water to the wetland.

c. A significant change in the quantity, timing or duration of the water entering the wetland.

d. The introduction of pollutants.

E. Long or short subdivision of lands in wetlands and associated buffers are subject to the following:

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

2. Land that is located partially within a wetland or its buffer may be subdivided; provided, that an accessible and contiguous portion of each new lot is located outside of the wetland and its buffer and meets minimum lot size requirements. All proposed lots must have sufficient buildable area once all zoning, critical areas, and other regulations are applied.

F. Exemptions and Allowed Uses in Wetlands.

1. The following wetlands may be exempt from the requirement to avoid impacts, and they may be filled if the impacts are fully mitigated based on the provisions of this chapter. If determined exempt by the administrator through agency consultation, impacts shall be mitigated through the purchase of credits from an in-lieu fee program or mitigation bank, consistent with the terms and conditions of the program or bank. In order to verify the following conditions, it is essential that a critical area report for wetlands be submitted.

a. All isolated Category IV wetlands less than four thousand (4,000) square feet that:

i. Are not associated with riparian areas or their buffers.

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

iii. Are not part of a wetland mosaic.

iv. Do not score six or more points for habitat function based on the 2014 update to the Washington State Wetland Rating System for Western Washington: 2014 Update (Ecology Publication No. 14-06-029, or as revised and approved by Ecology).

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.

b. Wetlands less than one thousand (1,000) square feet that meet the above criteria and do not contain federally listed species or their critical habitat are exempt from the buffer provisions contained in this chapter.

2. Activities Allowed in Wetlands. The activities listed below are allowed in wetlands. These activities do not require submission of a critical area report, except where such activities result in a loss of the functions and values of a wetland or wetland buffer. These activities include:

a. Existing and ongoing agricultural activities; provided, that they implement applicable best management practices (BMPs) contained in the latest editions of the USDA Natural Resources Conservation Service (NRCS) Field Office Technical Guide (FOTG); or develop a farm conservation plan in coordination with the local conservation district.

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

c. 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.

d. Drilling for utilities/utility corridors under a wetland, with entrance/exit portals located completely outside of the wetland buffer; provided, that the drilling does not interrupt the groundwater connection to the wetland or percolation of surface water down through the soil column. 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 will be disturbed.

e. Enhancement of a wetland through the removal of nonnative invasive plant species. Removal of invasive plant species shall be restricted to hand removal unless permits from the appropriate regulatory agencies have been obtained for approved biological or chemical treatments. All removed plant material shall be taken away from the site and appropriately disposed of. Plants that appear on the Washington State Noxious Weed Control Board list of noxious weeds must be handled and disposed of according to a noxious weed control plan appropriate to that species. Revegetation with appropriate native species at natural densities is allowed in conjunction with removal of invasive plant species.

f. Educational and scientific research activities.

g. Normal and routine maintenance and repair of any existing public or private facilities within an existing right-of-way; provided, that the maintenance or repair does not expand the footprint of the facility.

h. Stormwater management facilities. A wetland or its buffer can be physically or hydrologically altered to meet the requirements of a low impact development (LID), runoff treatment or flow control BMP if all of the following criteria are met:

i. The wetland is classified as a Category IV or a Category III wetland with a habitat score of three to four points; and

ii. There will be no net loss of functions and values of the wetland; and

iii. The wetland does not contain a breeding population of any native amphibian species; and

iv. The hydrologic functions of the wetland can be improved as outlined in questions 3, 4, 5 of Chart 4 and questions 2, 3, 4 of Chart 5 in the "Guide for Selecting Mitigation Sites Using a Watershed Approach," (available here: http://www.ecy.wa.gov/biblio/0906032.html); or the wetland is part of a priority restoration plan that achieves restoration goals identified in a shoreline master program or other local or regional watershed plan; and

v. The wetland lies in the natural routing of the runoff, and the discharge follows the natural routing, with the discharge point located in the outer twenty-five (25) percent of the buffer area; and

vi. All regulations regarding stormwater and wetland management are followed, including but not limited to local and state wetland and stormwater codes, manuals, and permits; and

vii. Modifications that alter the structure of a wetland or its soils will require permits. Existing functions and values that are lost would have to be compensated/replaced.

G. Critical Areas Report for Wetlands. If the administrator determines that the site of a proposed development includes or is adjacent to a wetland, the critical areas report shall require the following information in addition to the requirements for a critical areas report listed in Sections 18.06.080 and 18.06.090:

1. Documentation of any fieldwork performed on the site, including field data sheets for delineations, rating system forms, baseline hydrologic data, etc.

2. A description of the methodologies used to conduct the wetland delineations, wetland ratings, or impact analyses including references.

3. Hydrologic information such as location and condition of inlets/outlets (if they can be legally accessed), estimated water depths within the wetland, and estimated hydroperiod patterns based on visual cues (e.g., algal mats, drift lines, flood debris, etc.). Provide acreage estimates, classifications, and ratings based on entire wetland complexes, not only the portion present on the proposed project site.

4. A description of the proposed actions including an estimation of acreages of impacts to wetlands and buffers based on the field delineation and survey and an analysis of site development alternatives including a no-development alternative.

5. A depiction of the proposed stormwater management facilities and outlets (to scale) for the development, including estimated areas of intrusion into the buffers of any critical areas. The written report shall contain a discussion of the potential impacts to the wetland(s) associated with anticipated hydroperiod alterations from the project.

H. Wetland Buffer Requirements. The following buffer widths have been established in accordance with the best available science. They are based on the category of wetland and the habitat score as determined by a qualified wetland professional using the Washington State Wetland Rating System for Eastern Washington: 2014 Update (Ecology Publication No. 14-06-030, or as revised and approved by Ecology). The adjacent land use intensity is assumed to be high.

1. For wetlands that score six points or more for habitat function, the buffers in Table 18.06.160(H)-1 can be used if both of the following criteria are met:

a. A relatively undisturbed, vegetated corridor at least one hundred (100) feet wide is protected between the wetland and any other priority habitats as defined by the Washington State Department of Fish and Wildlife. The corridor must be protected for the entire distance between the wetland and the priority habitat by some type of legal protection such as a conservation easement. Presence or absence of a nearby habitat must be confirmed by a qualified biologist. If no option for providing a corridor is available, Table 18.06.160(H)-1 may be used with the required measures in Table 18.06.160(H)-2 alone.

b. The measures in Table 18.06.160(H)-2 are implemented, where applicable, to minimize the impacts of the adjacent land uses.

2. For wetlands that score three to five habitat points, only the measures in Table 18.06.160(H)-2 are required for the use of Table 18.06.160(H)-3. If an applicant chooses not to apply the mitigation measures in Table 18.06.160(H)-2, or is unable to provide a protected corridor where available, then Table 18.06.160(H)-3 must be used.

3. The buffer widths in Tables 18.06.160(H)-1 and 18.06.160(H)-3 assume that the buffer is vegetated with a native plant community appropriate for the ecoregion. If the existing buffer is unvegetated, sparsely vegetated, or vegetated with invasive species that do not perform needed functions, the buffer should either be planted to create the appropriate plant community or the buffer should be widened to ensure that adequate functions of the buffer are provided.

Table 18.06.160(H)-1: Wetland Buffer Requirements—Eastern Washington
Wetland Category	Buffer width (in feet) based on habitat score
	3-5	6-7	8-9
Category I: Based on total score	75	110	150
Category II: Based on total score	75	110	150
Category II: Vernal pool	150 (buffer width not based on habitat scores)
Category III (all)	60	110	150
Category IV (all)	40

Table 18.06.160(H)-2: Required Measures to Minimize Impacts to Wetlands (All measures are required, where applicable to a specific proposal)
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 feet 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 stormwater 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

Table 18.06.160(H)-3: Wetland Buffer Requirements for Eastern Washington if Table 18.06.160(H)-2 is NOT Implemented or Corridor NOT Provided
Wetland Category	Buffer width (in feet) based on habitat score
	3-5	6-7	8-9
Category I: Based on total score	100	150	200
Category II: Based on total score	100	150	200
Category II: Vernal pool	200 (buffer width not based on habitat scores)
Category III (all)	80	150	200
Category IV (all)	50

4. Increased Wetland Buffer Area Width. Buffer widths shall be increased on a case-by-case basis when a critical areas report establishes a larger buffer is necessary to protect wetland functions and values. This determination shall be supported by appropriate documentation showing that it is reasonably related to protection of the functions and values of the wetland. The documentation must include but not be limited to the following criteria:

a. The wetland is used by a state or federally listed plant or animal species or has essential or outstanding habitat for those species, or has unusual nesting or resting sites such as heron rookeries or raptor nesting trees; or

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

c. The adjacent land has minimal vegetative cover or slopes greater than thirty (30) percent.

5. Wetland Buffer Width Averaging to Improve Wetland Protection. The administrator may allow averaging of wetland buffer widths in accordance with an approved critical area report, provided all the following conditions are met:

a. The wetland has significant differences in characteristics that affect its habitat functions, such as a wetland with a forested component adjacent to a degraded emergent component or a "dual-rated" wetland with a Category I area adjacent to a lower-rated area.

b. The buffer is increased adjacent to the higher-functioning area of habitat or more-sensitive portion of the wetland and decreased adjacent to the lower-functioning or less-sensitive portion as demonstrated by a critical areas report from a qualified wetland professional.

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

d. The buffer at its narrowest point is never less than either three-fourths of the required width or seventy-five (75) feet for Category I and II, fifty (50) feet for Category III and twenty-five (25) feet for Category IV, whichever is greater.

6. Measurement of Wetland Buffers. All buffers shall be measured perpendicular from the wetland boundary as surveyed in the field. 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. Buffers must be fully vegetated in order to be included in buffer area calculations. Lawns, walkways, driveways, and other mowed or paved areas will not be considered buffers or included in buffer area calculations.

7. Buffers on Mitigation Sites. All wetland mitigation sites shall have buffers consistent with the buffer requirements of this chapter. Buffers shall be based on the expected or target category of the proposed wetland mitigation site.

8. Buffer Maintenance. Except as otherwise specified or allowed in accordance with this chapter, wetland buffers shall be retained in an undisturbed or enhanced condition. In the case of compensatory mitigation sites, removal of invasive nonnative weeds is required for the duration of the mitigation bond required under Section 18.06.110.

9. Impacts to Buffers. Requirements for the compensation for impacts to buffers are outlined in subsection (I) of this section.

10. Overlapping Critical Area Buffers. If buffers for two contiguous critical areas overlap (such as buffers for a stream and a wetland), the wider buffer applies.

11. Allowed Buffer Uses. The following uses may be allowed within a wetland buffer in accordance with the review procedures of this chapter, provided they are conducted in a manner so as to minimize impacts to the buffer and adjacent wetland:

a. Conservation or restoration activities aimed at protecting the soil, water, vegetation, or wildlife.

b. Passive recreation, including walkways, trails, and wildlife viewing structures located in the outer twenty-five (25) percent of the wetland buffer.

c. Educational and scientific research activities.

d. Normal and routine maintenance and repair of any existing public or private facilities within an existing right-of-way; provided, that the maintenance or repair does not increase the footprint or use of the facility or right-of-way.

e. 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.

f. Drilling for utilities/utility corridors under a buffer, with entrance/exit portals located completely outside of the wetland buffer boundary; 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.

g. Enhancement of a wetland buffer through the removal of nonnative invasive plant species. Removal of invasive plant species shall be restricted to hand removal. All removed plant material shall be taken away from the site and appropriately disposed of. Plants that appear on the Washington State Noxious Weed Control Board list of noxious weeds must be handled and disposed of according to a noxious weed control plan appropriate to that species. Revegetation with appropriate native species at natural densities is allowed in conjunction with removal of invasive plant species.

h. Repair and maintenance of nonconforming uses or structures, where legally established within the buffer, provided they do not increase the degree of nonconformity.

12. Signs and Fencing of Wetlands and Buffers.

a. Temporary Markers. The outer perimeter of the wetland buffer and the clearing limits identified by an approved permit or authorization shall be marked in the field with temporary "clearing limits" fencing in such a way as to ensure that no unauthorized intrusion will occur. The marking is subject to inspection by the 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 administrator may require the applicant to install permanent signs along the boundary of a wetland or buffer. 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 every fifty (50) feet, or one per lot if the lot is less than fifty (50) feet wide, and must be maintained by the property owner in perpetuity. The signs shall be worded as follows or with alternative language approved by the administrator:

Protected Wetland Area

Do Not Disturb

These signs may be modified as necessary to assure protection of sensitive features or wildlife.

c. Fencing. 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. Fencing installed as part of a proposed activity or as required in this subsection shall be designed to avoid interference with species migration, including fish runs, and shall be constructed in a manner that minimizes impacts to the wetland and associated habitat.

I. Compensatory Mitigation.

1. Mitigation Sequencing. Before impacting any wetland or its buffer, an applicant shall demonstrate that the following actions have been taken. Actions are listed in the order of preference:

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

b. Minimize 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. Rectify the impact by repairing, rehabilitating, or restoring the affected environment.

d. Reduce or eliminate the impact over time by preservation and maintenance operations.

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

f. Monitor the required compensation and take remedial or corrective measures when necessary.

2. Requirements for Compensatory Mitigation.

a. Compensatory mitigation for alterations to wetlands shall be used only for impacts that cannot be avoided or minimized and shall achieve equivalent or greater biologic functions. Compensatory mitigation plans shall be consistent with 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), and Selecting Wetland Mitigation Sites Using a Watershed Approach (Eastern Washington) (Publication No. 10-06-07, November 2010).

b. Mitigation ratios shall be consistent with subsection (I)(8) of this section.

c. Mitigation requirements may also be determined using the credit/debit tool described in "Calculating Credits and Debits for Compensatory Mitigation in Wetlands of Eastern Washington: Final Report (Ecology Publication No. 11-06-015, August 2012), consistent with subsection (I)(8) of this section.

3. Compensating for Lost or Affected Functions. Compensatory mitigation shall address the functions affected by the proposed project, with an intention to achieve functional equivalency or improvement of functions. The goal shall be for the compensatory mitigation to provide similar wetland functions as those lost, except 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 formally identified through agency consultation.

4. Approaches to Compensatory Mitigation. Mitigation for lost or diminished wetland and buffer functions shall rely on the approaches listed below:

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

i. The approval authority determines that it would provide appropriate compensation for the proposed impacts; and

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

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

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

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

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

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

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

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

c. Permittee-Responsible Mitigation. In this situation, the permittee performs the mitigation after the permit is issued and is ultimately responsible for implementation and success of the mitigation. Permittee-responsible mitigation may occur at the site of the permitted impacts or at an off-site location within the same watershed. Permittee-responsible mitigation shall be used only if the applicant's qualified wetland professional demonstrates to the approval authority's satisfaction that the proposed approach is ecologically preferable to use of a bank or ILF program, consistent with the criteria in this section.

5. Types of Compensatory Mitigation. Mitigation for lost or diminished wetland and buffer functions shall rely on a type listed below in order of preference. A lower-preference form of mitigation shall be used only if the applicant's qualified wetland professional demonstrates to the approval authority's satisfaction that all higher-ranked types of mitigation are not viable, consistent with the criteria in this section.

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

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

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

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

i. If a site is not available for wetland restoration to compensate for expected wetland and/or buffer impacts, the approval authority may authorize creation of a wetland and buffer upon demonstration by the applicant's qualified wetland professional that:

(A) The hydrology and soil conditions at the proposed mitigation site are conducive for sustaining the proposed wetland and that creation of a wetland at the site will not likely cause hydrologic problems elsewhere;

(B) Adjacent land uses and site conditions do not jeopardize the viability of the proposed wetland and buffer (e.g., due to the presence of invasive plants or noxious weeds, stormwater runoff, noise, light, or other impacts); and

(C) The proposed wetland and buffer will eventually be self-sustaining with little or no long-term maintenance.

c. Enhancement. The manipulation of the physical, chemical, or biological characteristics of a wetland site to heighten, intensify, or improve a specific function(s) or to change the growth stage or composition of the vegetation present. Enhancement is undertaken for specified purposes such as water quality improvement, flood water retention, or wildlife habitat. Enhancement results in a change in some wetland functions and can lead to a decline in other wetland functions, but does not result in a gain in wetland acres. Activities typically consist of planting vegetation, controlling nonnative or invasive species, modifying site elevations or the proportion of open water to influence hydroperiods, or some combination of these activities. Applicants proposing to enhance wetlands or associated buffers shall demonstrate how the proposed enhancement will increase the wetland's/buffer's functions, how this increase in function will adequately compensate for the impacts, and how existing wetland functions at the mitigation site will be protected.

d. Protection/Maintenance (Preservation). Removing a threat to, or preventing the decline of, wetland conditions by an action in or near a wetland. This includes the purchase of land or easements, or repairing water control structures or fences. This term also includes activities commonly associated with the term "preservation." Preservation does not result in a gain of wetland acres. Permanent protection of a Category I or II wetland and associated buffer at risk of degradation can be used only if:

i. The approval authority determines that the proposed preservation is the best mitigation option;

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

iii. The area proposed for preservation is of high quality or critical for the health of the watershed or basin due to its location;

iv. Permanent preservation of the wetland and buffer will be provided through a conservation easement or tract held by an appropriate natural land resource manager, such as a land trust.

v. The approval authority may approve other legal and administrative mechanisms in lieu of a conservation easement if it determines they are adequate to protect the site.

vi. Ratios for preservation in combination with other forms of mitigation generally range from ten (10) to one to twenty (20) to one, as determined on a case-by-case basis, depending on the quality of the wetlands being impacted and the quality of the wetlands being preserved. Ratios for preservation as the sole means of mitigation generally start at twenty (20) to one.

6. Location of Compensatory Mitigation. Compensatory mitigation actions shall generally be conducted within the same subdrainage basin and on the site of the alteration except when the applicant can demonstrate that off-site mitigation is ecologically preferable. The following criteria will be evaluated when determining whether the proposal is ecologically preferable:

a. There are no reasonable opportunities on site or within the subdrainage basin, or opportunities on site or within the subdrainage basin do not have a high likelihood of success based on a determination of the capacity of the site to compensate for the impacts. Considerations should include: anticipated replacement ratios for wetland mitigation, buffer conditions and proposed widths, available water to maintain anticipated hydrogeomorphic classes of wetlands when restored, proposed flood storage capacity, and potential to mitigate riparian fish and wildlife impacts.

b. On-site mitigation would require elimination of high-quality upland habitat.

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

d. Off-site locations shall be in the same subdrainage basin.

7. Timing of Compensatory Mitigation. Compensatory mitigation projects shall be completed prior to activities that will disturb wetlands. Construction of mitigation projects shall be timed to reduce impacts to existing fisheries, wildlife, and flora.The administrator may authorize a one-time temporary delay in completing construction or installation of the compensatory mitigation when the applicant provides a written explanation from a qualified wetland professional as to the rationale for the delay. An appropriate rationale would include identification of the environmental conditions that could produce a high probability of failure or significant construction difficulties.

8. Wetland Mitigation Ratios. The following ratios apply to the creation, restoration or preservation of wetlands that is in-kind, on-site, the same category, timed prior to or concurrent with alteration, and has a high probability of success:

Category and Type of Wetland	Creation or Reestablishment	Rehabilitation	Enhancement
I: Bog, Natural Heritage site	Not considered possible	Case by case	Case by case
I: Mature Forested	6:1	12:1	24:1
I: Based on functions	4:1	8:1	16:1
II:	3:1	6:1	12:1
III:	2:1	4:1	8:1
IV:	1.5:1	3:1	6:1

9. Compensatory Mitigation Plan. When a project involves wetland and/or buffer impacts, a compensatory mitigation plan prepared by a qualified professional shall be required, meeting the following minimum standards:

a. Wetland Critical Area Report. A critical area report for wetlands must accompany or be included in the compensatory mitigation plan.

b. Compensatory Mitigation Report. The critical areas report must include a written report and plan sheets that follow the guidance established in 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).

10. Buffer Mitigation Ratios. Impacts to buffers shall be mitigated at a minimum one-to-one ratio. Compensatory buffer mitigation shall replace those buffer functions lost from development.

11. Protection of the Mitigation Site. The area where the mitigation occurred and any associated buffer shall be located in a critical area tract or a conservation easement.

12. Monitoring. Mitigation monitoring shall be required for a period necessary to establish that performance standards have been met, but not for a period less than five years. If a scrub-shrub or forested vegetation community is proposed, monitoring may be required for ten (10) years or more. The project mitigation plan shall include monitoring elements that ensure certainty of success for the project's natural resource values and functions. If the mitigation goals are not obtained within the initial five-year period, the applicant remains responsible for restoration of the natural resource values and functions until the mitigation goals agreed to in the mitigation plan are achieved.

13. Advance Mitigation. Mitigation for projects with preidentified impacts to wetlands may be constructed in advance of the impacts if the mitigation is implemented according to federal rules, state policy on advance mitigation, and state water quality regulations consistent with Interagency Regulatory Guide: Advance Permittee—Responsible Mitigation (Ecology Publication No. 12-06-015, Olympia, WA, December 2012).

14. Unauthorized Alterations and Enforcement for Wetlands and Wetland Buffers.

a. When a wetland or its buffer has been altered in violation of this chapter, all ongoing development work shall stop and the critical area shall be restored. The administrator shall have the authority to issue a "stop-work" order to cease all ongoing development work and order restoration, rehabilitation, or replacement measures at the owner's or other responsible party's expense to compensate for violation of provisions of this chapter.

b. Requirement for Restoration Plan. All development work shall remain stopped until a restoration plan is prepared and approved by the administrator. Such a plan shall be prepared by a qualified professional using the currently accepted scientific principles and shall describe how the actions proposed meet the minimum requirements described in subsection (I)(14)(c) of this section. The administrator shall, at the applicant or other responsible party's expense, seek expert advice in determining the adequacy of the plan. Inadequate plans shall be returned to the applicant or violator for revision and resubmittal.

c. Minimum Performance Standards for Restoration. The following minimum performance standards shall be met for the restoration of a wetland; provided, that if the applicant or other responsible party can demonstrate that greater functions and habitat values can be obtained, these standards may be modified:

i. The historic structure, functions, and values of the affected wetland shall be restored, including water quality and habitat functions.

ii. The historic soil types and configuration shall be restored to the extent practicable.

iii. The wetland and buffers shall be replanted with native vegetation that replicates the vegetation historically found on the site in species types, sizes, and densities. The historic functions and values should be replicated at the location of the alteration.

iv. Information demonstrating compliance with other applicable provisions of this chapter shall be submitted to the administrator.

d. Site Investigations. The administrator is authorized to make site inspections and take such actions as are necessary to enforce this chapter. The administrator shall present proper credentials and make a reasonable effort to contact any property owner before entering onto private property.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.170 Flood hazard areas.

A. Designation.

1. Frequently Flooded Areas.

a. The town of Winthrop designates those areas of special flood hazard indicated in the Flood Hazard Boundary Map/Flood Insurance Rate Map (or as amended) and Flood Boundary/Floodway Map (or as amended), together with the accompanying Flood Insurance Study for Community Number 530125A, issued November 2, 1977 (or as amended), as frequently flooded areas.

b. Since the above-referenced maps and flood insurance study are nearly thirty (30) years old, the town shall pursue remapping by FEMA to ensure accuracy of the floodway and floodplain boundaries when funding is available.

c. Flood hazards are not necessarily constrained to those areas detailed in the flood insurance study and maps, therefore, mapping for the areas of local concern shall be undertaken as information becomes available, subject to availability of funds.

2. Channel Migration Zones.

a. The town of Winthrop designates the severe and moderate channel migration zones identified in the Comprehensive Flood Hazard Management Plan, Appendix I, adopted July 16, 2003 (or subsequent updates), as channel migration zones.

b. Channel migration zones may be modified based on the findings of completed special studies related to channel migration zones. See "Requests for Reassessment of Channel Migration Zone Boundaries" in subsection D of this section.

3. Incorporation of Monitoring Data. The town's Comprehensive Flood Hazard Management Plan (CFHMP) calls for monitoring to develop additional data about the floodplain and flood hazard areas. The town shall use the data from any flood hazard monitoring programs (as well as other data as they become available) to update local flood hazard maps, including channel migration zone boundaries.

B. Mapping. The flood hazard boundary map/flood insurance rate map and flood boundary/floodway map referred to above (or subsequent revisions to those maps), shall serve as the official maps of frequently flooded areas. The maps in the Comprehensive Flood Hazard Management Plan, Appendix I, referred to above (or subsequent revisions to those maps), shall serve as the official maps of channel migration zones. Those official maps, along with supporting documentation, shall be used to review development proposals.

C. Standards. In addition to the general provisions of this chapter and the requirements of the underlying zone, the following minimum standards shall apply to development activities within and adjacent to flood hazard areas:

1. All development within flood hazard areas shall be reviewed under and subject to the requirements of Chapter 15.12, Flood Damage Prevention Regulations.

2. All development within flood hazard areas shall be consistent with the goals, objectives, findings, and recommendations of the town's CFHMP. The CFHMP, along with the town's comprehensive plan, provides a policy basis for management of flood hazard areas.

3. Where practical, development activities shall be coordinated with structural activities recommended in the CFHMP.

4. Where flood hazard areas coincide with other designated critical areas, critical areas reports and mitigation plans shall address any combined functions and values.

5. In all cases where mitigation measures are proposed, said measures shall be consistent with the town's CFHMP.

6. Structures shall be located outside of flood hazard areas except where no alternative location exists.

7. Following construction of a structure within the floodplain where base flood elevation is provided, the applicant shall obtain an elevation certificate that records the elevation of the lowest floor. The elevation certificate shall be completed by a surveyor licensed in the state of Washington and shall be submitted to the town for recording.

8. Fill and grading in flood hazard areas shall occur only upon a determination by a qualified professional that the fill or grading will not block side channels, inhibit channel migration, increase flood hazards to others, or be placed within a defined channel migration zone.

9. Subdivision in flood hazard areas is subject to the following:

a. All lots created shall have adequate building space outside flood hazard areas, including the floodway, one hundred (100) year floodplain, and channel migration zones;

b. Plat maps shall indicate the floodway, one hundred (100) year floodplain and channel migration zone;

c. Subdivisions shall be designed to minimize or eliminate the potential for flood damage; and

d. Subdivisions shall provide for stormwater drainage, in accordance with town standards, so as to reduce exposure to flood hazards.

10. Development within the severe hazard channel migration zone shall be allowed only upon a determination by a qualified professional that the development will not limit channel migration or avulsion; require current or future bank stabilization; affect upstream or downstream properties; or result in a net loss of ecological functions associated with rivers and streams.

11. Upon development of properties within channel migration zones under this chapter, a notice shall be placed on the title of the property and recorded by the Okanogan County auditor. The notice shall serve to notify future owners of the property that the property and any structures on the property are subject to potential risks related to channel migration.

a. The notice on the title to properties located in moderate hazard channel migration zones shall read as follows:

"NOTICE"

This property has been identified as being within a Moderate Hazard Channel Migration Zone, and may be subject to risks from overbank flooding, bank erosion, and/or channel migration. Based on historic data, the channel or stream may erode or migrate and change locations over time, possible undercutting or eroding portions of this property. Structures and/or property may be at risk from flood inundation and/or the migrating channel and could be damaged or destroyed. Activities in the channel migration zone are subject to the provisions of the town of Winthrop's Comprehensive Flood Hazard Management Plan, Floodplain Development Ordinance, and Critical Areas Ordinance.

b. The notice on the title to properties located in severe hazard channel migration zones shall read as follows:

"NOTICE"

This property has been identified as being within a Severe Hazard Channel Migration Zone, and may be subject to risks from overbank flooding, bank erosion, and/or channel migration. Based on historic data, the channel or stream may erode or migrate and change locations over time, possible undercutting or eroding portions of this property. Structures and/or property may be at risk from flood inundation and/or the migrating channel and could be damaged or destroyed. Activities in the channel migration zone are subject to the provisions of the town of Winthrop's Comprehensive Flood Hazard Management Plan, Floodplain Development Ordinance, and Critical Areas Ordinance.

12. Bank Stabilization Projects. Bank stabilization (and other actions to prevent bank erosion and/or scour) within channel migration zones shall be subject to the following standards:

a. Protection of structures, public roadways or sole access routes in existence before the effective date of the critical areas ordinance codified in this chapter shall be allowed;

b. Within the severe channel migration hazard zone, no new bank stabilization structures or maintenance of existing bank stabilization structures will be allowed after the effective date of the critical areas ordinance codified in this chapter unless the planning and design of the proposed bank stabilization project incorporates an engineering assessment that includes evaluation of potential impacts at a river-reach scale (i.e., evaluates impacts that may occur as a result of the proposed project in up- and downstream reaches from the project site). All bank stabilization projects shall be consistent with the recommendations in the town of Winthrop's Comprehensive Flood Hazard Management Plan (CFHMP). Means and methods for stabilizing eroding stream banks shall look at erosion and/or scour issues at the river-reach scale rather than relative to individual property boundaries. Bank stabilization projects shall use soft approaches that assure no net loss of ecological functions unless it can be demonstrated that a different technique is needed because a structure is in imminent danger. Proof of imminent danger must be demonstrated by a qualified professional's report showing that damage to the structure can be expected within three years as a result of erosion.

c. Bank stabilization projects shall be allowed in the moderate channel migration hazard zone where such activity will not result in interference with the process of channel migration that may cause significant adverse impacts to property or public improvement and/or result in a net loss of ecological functions associated with rivers and streams, and subject to all other applicable regulations.

D. Requests for Reassessment of Channel Migration Zone Boundaries. A landowner or other project proponent may request reassessment of channel migration zone boundaries, including the locations of avulsion hazard zones, channel migration zones, and erosion hazard zones, by submitting a special study to the town for review and consideration.

1. A site-specific special study of a channel migration hazard shall be prepared by a qualified and licensed engineer, geologist, engineering geologist, or hydrogeologist who is experienced in the fields of fluvial geomorphology and river dynamics.

2. A special study of a channel migration hazard shall be consistent with A Framework for Delineating Channel Migration Zones (Washington Department of Ecology Publication No. 03-06-027, or as revised), including using terminology and methods consistent with the guidance in that publication.

3. A special study must include the following:

a. Vicinity map and site map with scale, north arrow, and parcel number(s) of the specific site being studied;

b. A clear statement of the requested revision or exception to the provision(s) of the channel migration hazard maps in the Comprehensive Flood Hazard Management Plan, Appendix I;

c. A clear presentation of all required study steps (as outlined above);

d. A clearly stated conclusion of the special study results that supports the requested revision. The conclusion must document the basis for the revision, show how the data presented refute the data used in the Comprehensive Flood Hazard Management Plan, Appendix I, and calculate the new results using the new information; and

e. A clearly marked map showing the requested revision to the maps in the Comprehensive Flood Hazard Management Plan, Appendix I.

4. On receipt of a special study, the town will review the study for completeness and request any additional materials, data, or information needed to support the review. The review will include a site visit by a representative of the town. Prior to the decision on a permit, staff will inform the applicant of the decision on the boundary reassessment. If the premise of the special study is accepted, the town will provide the applicant with a revised map of the channel migration zone boundary.

5. The administrator's decision on a reassessment request and corresponding special study may be appealed to town council.

(Ord. 744 § 1 (Exh. A), 2021)

§ 18.06.180 Geologically hazardous areas.

A. Designations. Geologically hazardous areas are designated as follows:

1. Erosion Hazard Areas. Erosion hazard areas are those areas that contain all three of the following characteristics:

a. A slope of thirty (30) percent or greater;

b. Areas identified by the Natural Resource Conservation Service (NRCS) as having a "moderate to severe," "severe," or "very severe" rill and inter-rill erosion hazard; and

c. Areas that are exposed to the erosion effects of wind or water.

2. Landslide Hazard Areas. Landslide hazard areas include areas potentially subject to landslides based on a combination of geologic, topographic and hydrologic factors. They include areas susceptible because of any combination of bedrock, soil, slope, aspect, structure, or hydrology. Examples include, but are not limited to:

a. Areas that have historically been prone to land sliding.

b. Areas containing soil types identified by the Natural Resource Conservation Service (NRCS) as unstable and prone to landslide hazard.

c. Areas with slopes greater than fifteen (15) percent, hillsides with intersecting geologic contacts with relatively permeable sediment overlying a relatively impermeable sediment or bedrock, and springs or groundwater seepage.

d. Areas that are potentially unstable as a result of rapid stream incision or stream bank erosion.

e. Areas with slopes of forty (40) percent or steeper and with a vertical relief of ten (10) or more feet except areas composed of consolidated rock.

3. Mine Hazard Areas. Mine hazard areas include areas that are directly underlain by, adjacent to, or affected by mine workings such as adits, tunnels, drifts, or air shafts with the potential for creating large underground voids susceptible to collapse, tailings piles, and waste rock. In addition, steep and unstable slopes created by open mines, tailings and waste rock piles have the potential for being mine hazard areas. Mine hazard areas are based upon the identification of active or historic mining activity and site-specific information regarding topography and geology. There are no known mine sites in Winthrop.

4. Seismic Hazard Areas. Seismic hazard areas are subject to severe risk of damage as a result of earthquake induced ground shaking, slope failure, settlement or soil liquefaction. There are no known active faults in Winthrop. The majority of the town is located within seismic zone 2B in accordance with the Uniform Building Code (1991 Edition, as amended). Susceptibility of land within the town to liquefaction is "very low to low," according to the Washington Department of Natural Resources (DNR) liquefaction susceptibility map for Okanogan County.

5. Volcanic Hazard Areas. Volcanic hazard areas are subject to pyroclastic flows, lava flows, and inundation by debris flows, mudflows, or related flooding resulting from volcanic activity. There are no such areas in Winthrop.

B. Mapping. NRCS maps shall be used to identify areas of erosion potential. Soils information should be combined with site-specific information (rills, inter-rills, and wind erosion) to determine if erosion hazard is present on the site.

C. Standards. In addition to the general provisions of this chapter and the requirements of the underlying zone, the following minimum standards shall apply to development activities within and adjacent to geologic hazard areas:

1. Any critical areas report for a geologically hazardous area shall include a geotechnical analysis completed by a qualified professional with expertise in the particular hazard(s) present in a given critical area.

2. Alterations of geologically hazardous areas or associated buffers may only occur for activities that:

a. Will not increase the threat of the geological hazard to adjacent properties beyond predevelopment conditions;

b. Will not adversely impact other critical areas;

c. Are designed so that the hazard to the project is eliminated or mitigated to a level equal to or less than predevelopment conditions; and

d. Are certified as safe as designed and under anticipated conditions by a qualified engineer or geologist, licensed in the state of Washington.

3. Mitigation plans for geologically hazardous areas shall establish setbacks and buffer widths as needed to eliminate or minimize risks of property damage, death, or injury resulting from development of the hazard area. Where established, buffers shall be maintained between all permitted uses and activities and the designated geologically hazardous area(s).

4. Unless otherwise provided or as part of an approved alteration, removal of vegetation from an erosion or landslide hazard area or related buffer shall be prohibited. Where removal of vegetation is unavoidable, reseeding and replanting with native vegetation shall be required, to assist in stabilization of the areas and to discourage establishment of invasive plants.

5. Structures and improvements shall be clustered to avoid geologically hazardous areas and other critical areas.

6. Every erosion hazard area mitigation plan shall include a runoff management plan or an erosion control plan to reduce sedimentation problems.

7. Development and activities located within landslide or erosion hazard areas shall provide for long-term slope stability, and design shall incorporate the following standards:

a. Structures and improvements shall minimize alterations to the natural contour of the slope and foundations shall be tiered where possible to conform to existing topography;

b. Structures and improvements shall be located to preserve the most critical portion of the site and its natural landforms and vegetation;

c. The proposed development shall not result in greater risk or a need for increased buffers on neighboring properties;

d. The use of retaining walls that allow the maintenance of existing natural slope area is preferred over graded artificial slopes; and

e. Development shall be designed to minimize impervious lot coverage.

8. Utility lines and pipes shall be permitted in erosion and landslide hazard areas only when the applicant demonstrates that no other practical alternative is available.

9. Subdivision of lands in erosion, landslide, and mine hazard areas is subject to the following:

a. Land that is located wholly within an erosion, landslide or mine hazard area or its buffer may not be subdivided. Land that is located partially within an erosion, landslide or mine hazard area or its buffer may be divided; provided, that each resulting lot has sufficient buildable area outside of, and will not affect, the geologic hazard area.

b. Access roads and utilities may be permitted within the erosion, landslide or mine hazard area and associated buffers only if no other feasible alternative exists.

10. Should a mine hazard area be identified in Winthrop, the site shall be noted on site plans for any development activity, and a geotechnical analysis shall be required to determine safety distances.

11. Prior to development of a site that is contaminated from previous mining activities, and where a significant hazard to health or the environment may be identified, the landowner or other project proponent shall be required to prepare and implement a reclamation plan.

12. All development activities in seismic hazard areas shall be required to conform to the applicable provisions of the Uniform Building Code that contains structural safeguards to reduce the risks from seismic activity.

(Ord. 744 § 1 (Exh. A), 2021)