Chapter 18.90 CRITICAL AREAS

A. The purpose of critical area regulations in this chapter is to designate and classify ecologically sensitive and hazardous areas and to protect them and their functions and values, while also allowing for reasonable use of private property.

B. Critical area regulations in this chapter implement the goals, policies, guidelines, and requirements of the city comprehensive plan and the Growth Management Act as they relate to critical areas.

C. The city finds that critical areas provide a variety of valuable and beneficial biological and physical functions that benefit the city and its residents. The beneficial functions and values provided by critical areas include, but are not limited to, water quality protection and enhancement, fish and wildlife habitat, food chain support, flood storage, conveyance and attenuation of flood waters, groundwater recharge and discharge, erosion control, protection from hazards, historical, archaeological, and aesthetic value protection, and recreation. These beneficial functions and values are not listed in order of priority. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.010)), 2010.]

18.90.020 Applicability.

A. The city shall regulate all uses, activities, and developments within, adjacent to, or likely to affect one or more critical areas, consistent with the provisions of best available science and this title.

B. Critical areas regulated by this chapter include:

1. Geologically sensitive areas;

2. Fish and wildlife habitat conservation areas;

3. Wetlands; and

4. Critical aquifer recharge areas.

C. All areas within the city meeting the definition of one or more critical areas, regardless of any formal identification, are hereby designated critical areas and are subject to the provisions of critical area regulations in this chapter.

D. The approximate location and extent of many of the critical areas within the city are shown on critical area maps available for public review at the city administrative offices. These maps may not include the location of all critical areas; therefore, it is the actual presence of critical areas that triggers the requirements of this chapter, whether or not the critical area is identified on the maps provided by the city.

E. The city also contains frequently flooded areas, which are considered critical areas and are regulated under Chapter 15.15 RMC, Floodplain Regulations. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.020)), 2010.]

18.90.030 Relationship to other regulations.

A. These critical area regulations shall apply as an overlay in addition to zoning and other development regulations adopted by the city. This chapter is not intended to repeal, abrogate or impair any existing regulations. Should a regulation in this chapter conflict with other regulations, the conflict shall be resolved in favor of the provision which provides the most protection environmentally to the critical areas unless specifically provided otherwise in this chapter or such provision conflicts with federal or state laws or regulations.

B. Any individual critical area adjoined by another type of critical area shall have the buffer and meet the requirements that provide the most protection to the critical areas involved. When any provision of this chapter or any existing regulation, easement, covenant, or deed restriction conflicts with this chapter, that which provides more protection to the critical areas shall apply.

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

D. The city shall not approve any permit or otherwise issue any authorization to alter the condition of any land, water, or vegetation, or to construct or alter any structure or improvement in, over, or on a critical area or associated buffer, without first ensuring compliance with the requirements of critical area regulations in this chapter.

E. Compliance with the provisions of this chapter does not constitute compliance with other federal, state, and local regulations and permit requirements that may be required. The applicant is responsible for complying with these requirements, apart from the process established in this chapter. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.030)), 2010.]

18.90.040 Exempt activities.

The following developments, activities, and associated uses may be exempted by the city from the provisions of this chapter:

A. Emergencies. Those activities necessary to prevent an immediate threat to public health, safety, or welfare, or that pose an immediate risk of damage to private property and that require remedial or preventive action in a time frame too short to allow for compliance with the requirements of this chapter. Within seven days of the emergency, the person or agency undertaking the action shall report any impacts to the critical area to the planning official. The planning official may require submittal of a critical area report to guide restoration or mitigation for these impacts. Final approval of the report, restoration and mitigation shall be in accordance with provisions of this chapter.

B. The property owner is responsible for fully restoring and/or mitigating any impacts to critical areas and buffers in accordance with the submitted report and/or mitigation plan.

C. Operation, maintenance, repair, modification, addition to, or replacement of existing structures, infrastructure improvements, utilities, public or private roads, dikes, levees, or drainage systems, if the activity does not further alter or increase the impact to, or encroach further within, a critical area or buffer and there is no increased risk to life or property as a result of the action. Operation and maintenance includes vegetation management performed in accordance with best management practices; provided, that such management actions are part of regular and ongoing maintenance, do not expand further into the critical area, are not the result of an expansion of a structure or utility, and do not directly impact species or habitat protected under RMC 18.90.210 through 18.90.260.

D. Educational and research activities that do not degrade the functions and values of a critical area or buffer. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.040)), 2010.]

18.90.050 Public agency and utility exceptions.

A. If the application of critical area regulations in this chapter 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.

B. Exception Request and Review Process. An application for a public agency and utility exception shall be processed as a Class 1 permit and shall include a critical area identification form; critical area report, including mitigation plan, if necessary; and any other related project documents, such as permit applications to other agencies, special studies, and environmental documents prepared pursuant to the State Environmental Policy Act.

C. Public Agency and Utility Review Criteria. The criteria for review and approval of public agency and utility exceptions are the following:

1. There is no other practical alternative to the proposed development with less impact on critical areas and their buffers, including impacts on water quality, erosion, habitat, native vegetation and significant trees;

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

3. The proposal does not pose a threat to the public health, safety, or welfare on or off the development proposal site;

4. The proposal protects and mitigates impacts to the functions and values of the critical area to the greatest extent feasible, consistent with the best available science;

5. The need for a public agency and utility exception is not the result of actions by the applicant after the effective date of the ordinance codified in this chapter, or its predecessor; and

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

D. The burden of proof shall be on the applicant to bring forth evidence in support of the application and to provide sufficient information on which any decision has to be made on the application. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.060)), 2010.]

18.90.070 Critical area identification form and report.

A. Submittal. Prior to the city’s consideration of any proposed activity not found to be exempt under RMC 18.90.040, the applicant shall submit to the planning official a complete critical area identification form on forms provided by the city.

B. Review Process. The planning official shall review the critical area identification form and conduct a site inspection and review other information available pertaining to the site and the proposal and make a determination as to whether any critical areas may be affected by the proposal. Critical area determinations shall be made through a Class 1 permit review.

If the planning official finds that no critical areas are present on or adjacent to the project area or that the proposal will not impact a critical area in a manner contrary to the purpose, intent and requirements of critical area regulations in this chapter, the planning official shall rule that the critical area review is complete and note on the identification form that no further review is required.

If the planning official finds that a critical area may be affected by the proposal, the planning official shall notify the applicant that a critical area report must be submitted prior to further review of the project, and indicate each of the critical area types to be addressed in the report. A determination regarding the absence of one or more critical areas by the planning official is not an expert certification regarding the presence of critical areas and is subject to possible reconsideration and reopening if new information is received.

C. Critical Area Report. Detailed requirements for critical area reports are identified in the articles for specific types of critical areas. Preparation of critical area reports and their review by the city, which may include referral to independent qualified professionals, shall be at the applicant’s expense. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.070)), 2010.]

18.90.090 Mitigation sequencing.

Applicants shall demonstrate to the satisfaction of the city 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 sequential order of preference, at the applicant’s expense; provided, that proposed mitigation may include a combination of measures:

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

B. 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;

C. Rectifying the impact to wetlands, critical aquifer recharge areas, 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;

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

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

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

G. Monitoring the hazard or other required mitigation and taking remedial action when necessary, as determined by the planning official. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.090)), 2010.]

18.90.100 Mitigation plan requirements.

When mitigation is required, the applicant shall submit for approval by the city a mitigation plan as part of the critical area report. Preparation of the mitigation plan and its review by the city, which may include referral to independent qualified professionals, shall be at the applicant’s expense. The mitigation plan shall include:

A. A written report identifying environmental goals and objectives of the compensation proposed, including:

1. A description of the existing critical area(s) and/or buffer(s) and their current conditions, functions, and values to serve as a baseline for measuring mitigation success;

2. A description of the anticipated impacts to the critical areas and the mitigating actions proposed, including the site selection criteria; mitigation goals and objectives, in relation to the functions and values of the impacted critical area; and dates for beginning and completion of mitigation activities;

3. A review of the best available science supporting the proposed mitigation and a description of the report author’s experience to date in restoring or creating the type of critical area proposed; and

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

B. Measurable specific criteria for evaluating whether or not the goals and objectives of the mitigation project have been successfully attained and whether or not the requirements of critical area regulations in this chapter have been met.

C. Details of the mitigation proposed, such as:

1. The proposed construction method, sequence, timing, and duration;

2. Grading and excavation details;

3. Erosion and sediment control features;

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

5. Measures to protect and maintain plants until established.

These written specifications shall be accompanied by detailed site diagrams, scaled cross-section drawings, topographic maps showing slope percentage and final grade elevations, and any other drawings appropriate to show construction techniques or anticipated final outcome.

D. A program for monitoring construction of the mitigation project and for assessing the completed project against its goals and objectives. A protocol shall be included outlining the schedule for site monitoring (for example, monitoring shall occur in years one, three, five, seven and 10 after site construction), and how monitoring data will be evaluated to determine if performance standards are being met. A monitoring report shall be submitted to document milestones, successes, problems, and contingency actions of the compensation project. The mitigation 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 in the case of mitigation for buffer alterations and for not less than 10 years for mitigation of wetland alterations. If performance standards are being met after these minimum periods, requirements for additional monitoring may be waived, if the planning official determines they are unnecessary.

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

F. Financial guarantees to ensure that the mitigation plan is fully implemented and meeting performance standards. Guarantees shall be in the form of a surety bond, performance bond, assignment of savings account, or an irrevocable letter of credit guaranteed by an acceptable financial institution with terms and conditions acceptable to the city. Guarantees shall remain in effect for a minimum of five years until the city determines, in writing, that the standards bonded for have been met, to ensure that the required mitigation has been fully implemented and demonstrated to function. Depletion, failure, or collection of bond funds shall not discharge the obligation of an applicant or violator to complete required mitigation, maintenance, monitoring, or restoration. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.100)), 2010.]

18.90.110 Determination.

A. Upon review of a critical area report, if the planning official determines that a proposed activity complies with the provisions of this chapter, the planning official shall prepare a written notice of determination and identify any required conditions of approval, which shall be attached to the underlying permit or approval. This determination shall be final concurrent with the final decision to approve, condition, or deny the development proposal or other activity involved. Critical areas determinations shall be processed as Class 1 reviews, consistent with Chapter 18.30 RMC.

B. If the planning official determines that a proposed activity does not adequately mitigate its impacts on critical areas, the planning official shall prepare written notice of the determination that includes findings of noncompliance. No proposed activity or permit shall be approved or issued if it is determined that the proposed activity does not comply with this chapter. Following notice of noncompliance, the applicant may request consideration of a revised critical areas report. If the revision is found to be substantial and relevant to the critical area review, the planning official may reopen the review and make a new determination based on the revised report. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1181 § 4, 2021; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.110)), 2010.]

18.90.120 Variances.

Variances from the standards of critical area regulations in this chapter may be authorized by the city in accordance with the provisions of Chapter 18.200 RMC.

A. Variance Criteria. A variance may be granted only if the applicant demonstrates that the requested action conforms to all of the criteria set forth in Chapter 18.200 RMC and as follows:

1. With mitigation, if necessary, the granting of the variance will not further degrade the functions or values of the associated critical areas or otherwise be materially detrimental to the public welfare or injurious to the property or improvements in the vicinity of the subject property; and

2. The decision to grant the variance includes the best available science and gives special consideration to conservation or protection measures necessary to preserve or enhance habitat for anadromous fish, species of local importance and state or federally designated endangered, threatened and sensitive species, as applicable.

B. Conditions May Be Required. In granting any variance, the city shall prescribe such conditions and safeguards as are necessary to secure adequate protection of critical areas from adverse impacts, and to ensure conformity with this chapter.

C. Time Limit. The city shall prescribe a time limit within which the action for which the variance is required shall be begun, completed, or both. Failure to begin or complete such action within the established time limit shall void the variance.

D. Burden of Proof. The burden of proof shall be on the applicant to bring forth evidence in support of the application and upon which any decision has to be made on the application. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.120)), 2010.]

18.90.130 Enforcement and penalties.

A. Inspections. Reasonable access to the site shall be provided to the city, state, and federal agency review staff for the purpose of inspections during any proposal review, restoration, emergency action, or monitoring period. The planning official shall present proper credentials and make a reasonable effort to contact any property owner before entering onto private property.

B. When a critical area or its buffer has been altered in violation of this chapter, all development activities shall stop and the critical area or buffer shall be restored in accordance with plans approved by the city. The city shall have the authority to issue a stop work order to cease all ongoing development activities 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. All development activities shall remain stopped until a restoration plan is prepared and approved by the city. Such a plan shall be prepared by a qualified professional using the best available science, as determined by the city, and shall describe how the actions proposed meet the minimum requirements described in subsection C of this section. The planning official shall, at the violator’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, at their expense.

C. Minimum Performance Standards for Restoration.

1. For alterations to critical aquifer recharge areas, wetlands, and habitat conservation areas, restoration shall return the affected environment to the historic conditions or the conditions existing at the time of the initiation of the project as determined by the city. If the city determines that restoration to historic or preexisting conditions is not feasible, then plans shall be submitted for city review and approval to replace, enhance, or provide substitute resources or environments meeting the criteria for mitigation in RMC 18.90.090 and 18.90.100.

2. For alterations to flood and geological hazards, the following minimum performance standards shall be met for restoration:

a. The hazard shall be reduced to a level equal to, or less than, the predevelopment hazard;

b. Any risk to public safety or other critical areas resulting from the alteration shall be eliminated or minimized; and

c. To the extent feasible, the hazard area and buffers shall be replanted with native vegetation sufficient to minimize the hazard.

D. Penalties. Any person convicted of violating any of the provisions of this chapter shall be guilty of a misdemeanor. Each day or portion of a day during which a violation of this chapter is committed or continued shall constitute a separate offense. Any development carried out contrary to the provisions of this chapter shall constitute a public nuisance and may be enjoined as provided by the statutes of the state of Washington. The city may levy civil penalties against any person, party, firm, corporation, or other legal entity for violation of any of the provisions of this chapter in accordance with the provisions of the city fee schedule. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.130)), 2010.]

18.90.140 Signs and fencing.

A. Temporary Markers. The outer perimeter of buffers and the clearing limits identified by an approved permit or authorization shall be marked in the field with temporary “clearing limits” fencing, approved by the city, to ensure that no unauthorized intrusion will occur. The marking is subject to inspection by the planning official 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 critical area regulations in this chapter, the planning official may require signs and/or fencing designed in accordance with city standards, identifying post-project buffers and critical areas as “Critical Areas.” If the buffers or critical areas have predominantly native vegetation or are so restored by the project, signs may use the term “native growth protection areas.”

C. Fencing. If the planning official determines fencing is necessary to protect the functions and values of the critical area, the planning official shall condition any permit or authorization issued pursuant to critical area regulations in this chapter to require the applicant to install a permanent fence at the edge of the critical area or its buffer in accordance with city fence standards. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.140)), 2010.]

18.90.150 Building setbacks.

Unless otherwise provided, buildings and other structures shall be set back a distance of 25 feet from the edges of all critical area buffers or from the edges of all critical areas, if no buffers are required. The following may be allowed in the building setback area:

A. Landscaping;

B. Uncovered decks to within five feet of the edge of required buffers, or the edge of critical areas if no buffers are required, in accordance with the provisions of RMC 18.50.030(A)(3); and

C. Impervious ground surfaces, such as driveways and patios; provided, that such improvements may be subject to water quality and stormwater management regulations. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.150)), 2010.]

Article II. Geologically Sensitive Areas

18.90.160 Designation of geologically sensitive areas.

Geologically sensitive areas include areas susceptible to erosion, sliding, subsidence, earthquake, or other geologic events and conditions. Improper and incompatible development sited in these areas can pose a threat to the health and safety of citizens, placing not only itself at risk, but also potentially creating or increasing hazards to surrounding development and land uses. As defined in this title, areas susceptible to one or more of the following types of hazards shall be designated as a geologically sensitive area:

A. Mine hazard areas;

B. Steep slopes; and

C. Unstable slopes. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.160)), 2010.]

18.90.170 Geologically sensitive areas.

A. Except as provided in RMC 18.90.180(A) and 18.90.190(E) and (F), all single-family and duplex residential development within 100 feet of a designated geologically sensitive area and all commercial, industrial, or multifamily developments within 200 feet of a designated geologically sensitive area shall be considered adjacent to the area and shall be required to submit a critical area report.

B. The report shall be prepared by a qualified professional, as defined in Chapter 18.20 RMC, and shall meet requirements of this section and RMC 18.90.180 and 18.90.190, as applicable. All critical area reports for geologically sensitive areas shall contain the following:

1. The name and contact information of the applicant, a description of the proposal, and identification of the permit requested; and

2. The dates, names, and qualifications of the persons preparing the report and documentation of any fieldwork performed on the site.

C. The report and its review by the city, which may include referral to independent qualified professionals, shall be at the applicant’s expense. The planning official shall approve the report only if it demonstrates that the proposed development will not increase the risk of harm to public safety, neighboring properties or critical areas. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.170)), 2010.]

18.90.180 Mine hazard areas.

A. A critical area report is not required for the following activities within or adjacent to mine hazard areas:

1. Construction of new nonresidential structures with less than 800 square feet of building footprint which are not used as places of employment or public assembly;

2. Single-family residential on infill lots in single-family residential zones; and

3. Installation of fences in accordance with city standards.

B. For all other development activities, a critical area report for a mine hazard area may be required, and shall include the following requirements:

1. A site plan, which shall delineate the following found within 200 feet of or directly underlying the project area, or that have potential to be affected by the proposal:

a. The proposed development, including the location of existing and proposed structures, fill, storage of materials, and drainage facilities, with dimensions indicating distances to critical areas and adjacent development;

b. The topography, in two-foot contours, of the project area and all geologically sensitive areas addressed in the report;

c. The location of any features of current or historic mines that may impact or be affected by the proposed activities;

d. The location of any known sinkholes, significant surface depressions, trough subsidence features, coal mine spoil piles, slag piles, or tipple piles, and other mine-related surface features; and

e. The location of any prior site improvements that have been carried out to mitigate abandoned coal mine features.

2. A hazards analysis, which shall include a discussion of the potential for subsidence on the site in response to an earthquake or other geologic event, and which shall classify all mine hazard areas within 200 feet of the project area, or that have potential to be affected by the proposal, as either low, moderate, or severe.

C. Alterations with a significant likelihood of affecting only mine hazard areas with a low potential for subsidence are permitted, subject to compliance with all other applicable requirements.

D. Alterations with a significant likelihood of affecting coal mine byproduct stockpiles or mine hazard areas with a moderate potential for subsidence are permitted, subject to a mitigation plan developed by a qualified professional to minimize risk of structural damage.

E. Alterations with a significant likelihood of affecting mine hazard areas with a severe potential for subsidence are not permitted except as authorized under subsection (A) of this section.

F. Access roads and utilities may be permitted within 200 feet of a mine hazard area with a moderate or severe potential for subsidence if the city determines that no other feasible alternative exists.

G. Land that is located within 200 feet of a mine hazard area with a severe potential for subsidence may not be subdivided. Land that is located partially within such an area may be subdivided; provided, that each resulting lot has sufficient buildable area at least 200 feet away from the severe hazard.

H. All reclamation activities, including grading, filling, and stockpile removal, must have as-built drawings submitted to the city in a format specified by the planning official. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.180)), 2010.]

18.90.190 Steep and unstable slopes.

A. To determine if a critical area report is required for development on or adjacent to slopes between 15 and 39 percent, the planning official may require the applicant to provide a letter prepared by a certified geologist or engineer to determine whether springs, groundwater seepage or other causes of potential instability are present on or affecting the subject slope.

B. New structures and additions to existing structures within or adjacent to a geologically sensitive area shall be set back a minimum of 25 feet from the top or toe of a steep or unstable slope unless a larger setback is recommended in a critical area report. In no case shall the setback be less than 25 feet from a steep or unstable slope unless allowed through the reasonable use provisions and supported by a critical area report approved by the planning official. Decks that add no substantial loading weight to the sensitive area and accessory buildings 120 square feet or less may extend into the setback area to within 10 feet of the top or toe of a steep or unstable slope.

C. After completion of the project, the top and toe of the steep or unstable slope shall be identified with signs as a critical area or native growth protection area, in accordance with RMC 18.90.140(B).

D. All clearing and grading shall follow at a minimum the current best management practices as contained in the Washington Department of Ecology’s most current Stormwater Management Manual for Eastern Washington. If best management practices are not implemented, construction shall be stopped immediately until proper erosion control devices are implemented and established. Best management practices include, but are not limited to:

1. Water flows shall be directed away from steep or unstable slopes. At no time shall water be allowed to flow freely over steep or unstable slopes.

2. Exposed soils shall be protected from the forces of rain and flowing water within one day during the winter season and three days during the summer season.

3. Erosion control devices shall include as appropriate silt fences, straw mats, hay bales, filter fabrics, plastic sheeting, mulch, retention of vegetative buffers, or soil stabilization plant materials.

4. Development shall be phased to limit the area of exposed soils to no more than one acre at a time.

5. Vegetation removal or planting on steep slopes shall be conducted by hand or by nonimpacting procedures as approved by the planning official.

E. For the following single-family and multifamily residential development applications, the planning official may waive the requirements for a critical area report, if the development is unlikely to have any impact on a steep or unstable slope:

1. Additions to a single-family residence with a building footprint less than 200 square feet, located so that the existing structure is between the addition and a steep or unstable slope.

2. Detached auxiliary buildings such as garages and sheds that are 50 feet or more away from a steep or unstable slope.

3. Decks attached to single-family and multifamily structures where no additional load bearing weight is added to an adjacent steep or unstable slope.

F. For the following development activities, a letter as described in this subsection, prepared by a qualified professional, may fulfill requirements for a critical area report:

1. Additions to single-family homes less than 30 percent of the building footprint.

2. Additions to a building’s height where the footprint of the existing structure is not changed.

3. Detached accessory buildings such as garages and sheds with no living spaces.

The letter shall include an assessment of the existing geologic and geotechnical site conditions, including surface water runoff, groundwater, soil types, erosion, and slope stability. The qualified professional shall prepare conclusions and recommendations on the suitability of the proposed development and any mitigation necessary to address existing site conditions that may need to be modified due to the proposed development.

G. All other development within or adjacent to a steep or unstable slope shall submit a critical area report that shall include a site assessment, geotechnical analysis, stormwater plan, grading and erosion control plan and landscape/revegetation plan, as described below:

1. Site Assessment. Along with standard site plan requirements, the following information shall be provided for the subject property, prepared by a licensed land surveyor:

a. Topography map at two-foot contour intervals for the entire site, including abutting public rights-of-way, private roads, or access easements;

b. Location of all significant trees;

c. Location of all manmade drainage structures or features including pipes, drains, catch basins, drainage structures, culverts, and under drain pipes;

d. Location of all frequently flooded areas, as defined in this title, and all wetlands, fish and wildlife habitat conservation areas, geologically sensitive areas, and other critical areas, as defined in this chapter, within 300 feet of the project area;

e. Location of all existing site improvements and the amount of existing impervious surface area;

f. Location of any existing cuts and fills; and

g. Location of all utilities, both above and below ground.

The site plan shall also include a vicinity map, showing the location of the property in relationship to surrounding lots and other critical areas.

2. Geotechnical Analysis. The analysis shall include an assessment of the geologic characteristics of the soils, sediments, and/or rock of the project area and potentially affected adjacent properties, and a review of the site history regarding landslides, erosion, and prior grading. Soils analysis shall be prepared in accordance with accepted classification systems in use in the region. The assessment shall include, but not be limited to:

a. Data regarding underlying geology, slope gradients, soil types, and subsurface information, including boring and/or test pit logs describing soil stratification and results of soil tests conducted;

b. Identification of any previous landslide activity in the vicinity of the project, and an assessment of the overall stability of slopes that could be affected by the development and the effect the development may have on these slopes over time;

c. Recommendations for grading procedures, fill placement, and compaction criteria, temporary and permanent slope inclinations and support, and design criteria for corrective measures and opinions and recommendations regarding the capabilities of the site;

d. Evaluation of the seismic stability of the site in drained and saturated conditions, including a statement that the design criteria of proposed structures consider a seismic event with a 10 percent probability of being exceeded in 50 years;

e. Potential for liquefaction and proposed mitigation measures;

f. A description of the hydrology (both surface and subsurface) of the site, including locations of any wetlands, streams, springs, seeps, and groundwater along with recommendations consistent with the city’s critical area regulations for addressing any impacts;

g. A recommendation on building site location, foundation type and depths, minimum building setbacks, minimum deck and accessory building setbacks, and if necessary the minimum no-disturbance setback from any steep or unstable slope. The analysis shall also include recommendations on the design of temporary and permanent retaining structures if any are proposed;

h. An estimate of bluff retreat rate that recognizes and reflects potential catastrophic events such as seismic activity or a 100-year storm event; and

i. Recommendations and requirements for handling contaminated soils and materials if encountered on the site.

3. Stormwater plan, which shall demonstrate compliance with the substantive requirements of Chapters 13.15 and 18.110 RMC for any development creating more than 1,000 square feet of impervious surface. For development activities that create less than 1,000 square feet of impervious surfaces, stormwater runoff shall be designed for natural infiltration or dispersion. At no time shall concentrated stormwater runoff be allowed to flow directly over a steep or unstable slope, or impact a neighboring property, city street, alley, or public right-of-way.

4. Grading and erosion control plan, which shall include:

a. A schedule showing estimated starting and completion dates for each stage of the project, limiting the time that soil is exposed and unprotected to the shortest possible period.

b. Measures to be taken for slope stabilization and erosion control, using best management practices as contained in the Washington Department of Ecology’s 2004 Stormwater Management Manual for Eastern Washington (Publication No. 04-10-076), or future updated publications or other methodology as approved by the planning official.

5. Landscape/revegetation plan, which shall include:

a. Measures to be taken to protect and replace natural vegetative cover;

b. A statement that vegetation trimming debris shall be removed from slopes in such a fashion as to not disturb existing vegetation; and

c. A schedule showing when each stage of the project will be revegetated, with estimated starting and completion dates. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.190)), 2010.]

18.90.200 Repair of slope instabilities.

Repair of slope instabilities and slope failures on an emergency basis shall be allowed by the planning official as needed to correct an immediate danger to the public health, welfare and safety. The planning official shall use the guidance of this article when evaluating the necessary repairs and add mitigation measures as appropriate to ensure that the intent of this article has been met. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.200)), 2010.]

Article III. Fish and Wildlife Habitat Conservation Areas

18.90.210 Designation of fish and wildlife habitat conservation areas.

Fish and wildlife habitat conservation areas include:

A. Areas with which state or federally designated endangered, threatened, and sensitive species have a primary association. The Washington Department of Fish and Wildlife, U.S. Fish and Wildlife Service, and the National Marine Fisheries Service should be consulted for current listing status;

B. State priority habitats and areas associated with state priority species, as identified by the Washington Department of Fish and Wildlife. State priority habitats include stream and adjacent riparian areas and urban natural open space;

C. Habitats of local importance, including the city’s urban forest and watershed zones, as defined in Chapter 18.80 RMC, and areas associated with species of local importance, including western bluebird (Sialia mexicana), great blue heron (Ardea herodias), osprey (Pandion haliaetus), mountain whitefish (Prosopium williamsoni), common merganser (Mergus merganser), cougar (Puma concolor) and black bear (Ursus americanus) and others as may be identified by the city in accordance with RMC 18.90.220;

D. Lakes or ponds that provide fish or wildlife habitat, except artificial ponds created for a nonwildlife purpose such as storm water detention facilities, wastewater treatment facilities, farm ponds, and temporary construction ponds; and

E. Areas of rare plant species or high quality ecosystems identified by the Washington State Department of Natural Resources through the Natural Heritage Program under Chapter 79.70 RCW. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.210)), 2010.]

18.90.220 Designation of habitats and species of local importance.

A. Habitats and species of local importance are those identified for protection by the city. Habitats may include a seasonal range or habitat element with which a species has a primary association, and which, if altered, may reduce the likelihood that the species will maintain and reproduce over the long term in this vicinity.

B. The city shall accept and consider nominations for habitat areas and species to be designated as locally important on an annual basis. Habitats and species may be nominated for designation by any person in a format prescribed or approved by the city.

C. Habitats and species to be designated shall exhibit at least one of the criteria in subsections (C)(1) through (3) of this section and shall meet criteria in subsections (C)(4) through (6) of this section.

1. Local populations of native species are vulnerable or declining or are likely to become threatened or endangered based on existing or predictable threats;

2. The species or habitat has recreational, commercial, game, tribal, or other special value;

3. Long-term persistence of a species within the urban growth area of Roslyn is dependent on the protection, maintenance and/or restoration of the nominated habitat;

4. Protection by county, state, or federal policies, laws, regulations, or nonregulatory tools is not adequate to prevent degradation of the species or habitat in the city;

5. Without protection, there is likelihood that the species or habitat will decline over the long term; and

6. Nominated areas must represent high-quality native habitat or habitat that either has a high potential to recover to a suitable condition and is of limited availability or provides landscape connectivity contributing to conservation of the designated species or habitat.

D. A petition in a format prescribed or approved by the city to nominate an area or a species to this category shall contain all of the following, using best available science:

1. A statement demonstrating that nomination criteria are met;

2. A proposal for whether specific habitat features should be protected (for example, nest sites, breeding areas, and nurseries), or whether the habitat or ecosystem is being nominated in its entirety;

3. Proposed management strategies for the species or habitats. Where restoration of habitat is proposed, a conceptual plan for restoration must be provided as part of the nomination;

4. Signatures of all petitioners.

E. The planning official shall determine whether the nomination proposal is complete and, if complete, shall evaluate it according to the characteristics enumerated in subsection (C) of this section and make a recommendation to the planning and historic preservation commission based on those findings.

F. The planning and historic preservation commission shall hold a public hearing for proposals found to be complete and make a recommendation to the city council based on the characteristics enumerated in subsection (C) of this section.

G. Following the recommendation of the planning and historic preservation commission, the city council shall hold an additional public hearing and shall determine by ordinance whether the designation criteria in this section have been met. Designation of a habitat or species of local importance shall be by ordinance.

H. Approved nominations shall be specified in RMC 18.90.210 and shall be subject to the provisions of critical area regulations in this chapter. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.220)), 2010.]

18.90.230 Fish and wildlife habitat conservation area mapping.

The following, in addition to critical area maps available through the city, may be used as a guide for locating fish and wildlife habitat conservation areas. These sources are to be used as references for the city, applicants and property owners, but may be superseded by new data:

A. Washington Department of Fish and Wildlife priority habitat and species maps;

B. Maps developed for Water Resources Inventory Area 39 (Upper Yakima River) by the Yakima Subbasin fish and wildlife planning board, including the distribution of salmon species; and

C. Washington State Department of Natural Resources Natural Heritage Program maps and mapping data. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.230)), 2010.]

18.90.240 Fish and wildlife habitat conservation area riparian buffers.

A. Standard Buffer Widths. Streams shall be protected with vegetated buffers, which also provide riparian wildlife habitat. These buffers shall have the following standard widths, measured perpendicular from the ordinary high water mark of the water body:

1. Crystal Creek and its tributaries: 100 feet;

2. All streams in the urban forest and watershed zones, including seasonal streams: 300 feet; and

3. All other streams: 50 feet.

B. Reductions for Lower Impact Land Uses. Except in the urban forest and watershed zones, standard buffer widths may be reduced up to 15 percent in conjunction with the approval of measures that will result in no net loss or a net gain in ecological function. This may include measures to minimize the impacts of the land use adjacent to the water body such as infiltration of stormwater, retention of native vegetation and soils, direction of noise and light away from the water body, and other measures that may be suggested by a qualified professional. The development of these measures and their review by the city, which may include referral to independent qualified professionals, shall be at the applicant’s expense. If proposed future land uses are more intense, they are not eligible to maintain this reduction.

C. Reductions for Restoration. Buffer widths may be reduced up to an additional 35 percent if the buffer is restored or enhanced from a preproject condition that is disturbed (e.g., dominated by invasive species), so that functions of the post-project buffer are equal or greater. The restoration plan must meet requirements in RMC 18.90.100 for a mitigation plan and RMC 18.90.250 for a critical area report. This reduction may be added to reductions for lower impact land uses.

D. Buffer Averaging. The planning official shall have the authority to average buffer widths on a case-by-case basis, where a qualified professional demonstrates to the planning official’s satisfaction that all of the following criteria are met:

1. The total area contained in the buffer after averaging is no less than that contained within the buffer prior to averaging;

2. Decreases in width are generally located where riparian functions may be less sensitive to adjacent land uses, and increases are generally located where riparian functions may be more sensitive to adjacent land uses, to achieve no net loss or a net gain in functions; and

3. The averaged buffer, at its narrowest point, shall never be less than 25 feet.

E. Signage. Signs shall identify post-project riparian buffers as critical areas or native growth protection areas, in accordance with the provisions of this title.

F. Allowed Uses. The following uses may be permitted within a riparian buffer, upon approval by the city, and provided they are not prohibited by any other applicable law and they are conducted in a manner so as to minimize negative impacts to the buffer and adjacent water body:

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

2. Passive recreation facilities consistent with an approved critical area report, including:

a. Wildlife viewing structures; and

b. Walkways and trails, provided pathways minimize adverse impacts on water quality. They should generally be parallel to the perimeter of the water body, located in the outer 25 percent of the riparian buffer area, and avoid removal of significant trees. They must be limited to pervious surfaces no more than four feet in width.

3. Stream crossings, if necessary to provide access to property and if impacts are fully mitigated consistent with an approved critical areas report.

4. Stormwater management facilities, limited to stormwater dispersion outfalls and bioswales, may be allowed within the outer 25 percent of riparian buffers; provided, that:

a. No other location with less impact is feasible; and

b. Mitigation for impacts is provided to achieve no net loss or a net gain in functions.

5. Streambank Stabilization. Streambank stabilization to protect structures from future channel migration is not permitted except when achieved through bioengineering or soft armoring techniques in accordance with an approved critical area report and all necessary state and federal permits.

6. Public Flood Protection Measures. New public flood protection measures and expansion of existing ones may be permitted, subject to the planning official’s review and approval of a critical area report and all necessary state and federal permits. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.240)), 2010.]

18.90.250 Fish and wildlife habitat conservation area critical area reports.

If required by the planning official in accordance with RMC 18.90.070(B), a critical area report for fish and wildlife habitat conservation areas shall meet requirements of this section. The report and its review by the city, which may include referral to independent qualified professionals, shall be at the applicant’s expense.

A. A critical area report shall be required for all development within 300 feet of any fish and wildlife habitat conservation area, as designated in RMC 18.90.210. A critical area report shall be required for all development within the urban forest or watershed zones.

B. At a minimum, the report shall contain the following:

1. The name and contact information of the applicant, a description of the proposal, and identification of the permit requested;

2. A copy of the site plan for the development proposal including:

a. A map to scale depicting fish and wildlife habitat conservation areas, wetlands, buffers, the development proposal, and any areas to be cleared or graded;

b. A description of the proposed storm water management plan for the development and consideration of impacts from drainage alterations; and

c. The dates, names, and qualifications of the persons preparing the report, documentation of any fieldwork performed on the site, and a description of the methodologies used to conduct habitat assessments and impact analyses, including references and all assumptions made or relied upon.

C. Proposals shall be exempt from further report requirements, if they are consistent with riparian buffer requirements in RMC 18.90.240(A) or allowed uses in RMC 18.90.240(F) and affect no other fish and wildlife habitat conservation areas beside streams and riparian areas.

D. Reports not exempt under subsection (C) of this section shall be prepared by a qualified biologist with experience preparing reports for the relevant type of habitat.

E. Critical area reports for fish and wildlife habitat conservation areas shall address the following geographic areas:

1. The land parcel of the proposed activity;

2. All fish and wildlife habitat conservation areas, including riparian buffers identified in RMC 18.90.240(A) within 300 feet of the project area; and

3. All wetlands and geologically sensitive areas within 300 feet of the project area.

F. A critical area report for a fish and wildlife habitat conservation area shall contain an assessment of habitats including the following information at a minimum:

1. A detailed description of vegetation throughout the areas identified in subsection (E) of this section;

2. Identification of any species of local importance or state priority species that have a primary association with habitat in these areas, and an assessment of potential project impacts on the species;

3. A discussion of any federal, state, or local special management recommendations, including Washington Department of Fish and Wildlife habitat management recommendations, that have been developed for habitats located in these areas or the species identified in subsection (F)(2) of this section;

4. A proposed habitat management plan for the site, which must be approved by the Washington Department of Fish and Wildlife for state priority species;

5. A detailed discussion of the direct and indirect potential cumulative impacts on habitat from development of the site, including potential impacts to water quality;

6. An analysis of site development alternatives, including a no development alternative;

7. A discussion of proposed mitigation, consistent with RMC 18.90.090, Mitigation sequencing, and RMC 18.90.100, Mitigation plan requirements; and

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

G. When appropriate, due to the type of habitat or species present or the project area conditions, the planning official may also require the habitat management plan developed under subsection (F)(4) of this section to include:

1. An evaluation by an independent qualified professional regarding the applicant’s analysis and the effectiveness of any proposed mitigating measures or programs, to include any recommendations as appropriate;

2. A request for consultation with the Washington Department of Fish and Wildlife, the local Native American Indian tribe and other appropriate agency; and

3. Detailed surface and subsurface hydrologic features both on and adjacent to the site.

H. Unless otherwise provided, a critical area report may be supplemented by or composed of, in whole or in part, any reports or studies required by other laws and regulations or previously prepared for and applicable to the development proposal site, as approved by the planning official. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.250)), 2010.]

18.90.260 Approval of activities.

The planning official shall condition approval of activities allowed within or adjacent to a habitat conservation area or its buffers, as necessary to minimize or mitigate any potential adverse impacts. Conditions shall be based on the best available science and may include, but are not limited to, the following:

A. Establishment of buffer zones;

B. Preservation or restoration of critically important vegetation and/or habitat features such as snags and downed wood;

C. Preservation or restoration of contiguous wildlife habitat corridors, to minimize the isolating effects of development on habitat areas;

D. Limitation of access to the habitat area, including signs and fencing to deter unauthorized access;

E. Seasonal restriction of construction activities;

F. Establishment of a duration and timetable for periodic review of mitigation activities;

G. In the urban forest and watershed zones, actions that would help achieve the city’s desired future conditions for those zones, which include a landscape structure that mimics historical late successional Douglas fir and Ponderosa pine forests characteristic of the fire disturbance regime in the eastern Cascades, with varying degrees of tree densities and canopy closures, providing habitat connectivity for wildlife; and

H. Requirement of a performance bond, when necessary, to ensure completion and success of proposed mitigation. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.260)), 2010.]

Article IV. Wetlands

18.90.270 Wetland identification and rating.

A. Identification and Delineation. Wetlands shall be identified and delineated by a qualified wetland professional in accordance with the Washington State Wetlands Identification and Delineation Manual (Washington Department of Ecology Publication No. 96-94, or as revised and approved by Ecology), using the criteria in the definition of wetland in Chapter 18.20 RMC. Such wetland delineations are valid for three years; after such date the city shall determine if a revision or additional assessment is necessary.

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 (Ecology Publication No. 04-06-015, or as revised and approved by Ecology), which contains the definitions and methods for determining if the criteria below are met.

1. Category I wetlands include:

a. Wetlands identified by scientists of the Washington Department of Natural Resources Natural Heritage Program as high quality wetlands;

b. Bogs larger than one-half acre;

c. Mature forested wetlands larger than one acre; or

d. Wetlands that perform many functions well (scoring at least 70 points under the Department of Ecology’s rating system).

2. Category II wetlands include:

a. Wetlands identified by the Washington State Department of Natural Resources as containing sensitive plant species;

b. Bogs between one-fourth and one-half acre in size; or

c. Wetlands with a moderately high level of functions (scoring between 51 and 69 points under the Department of Ecology’s rating system).

3. Category III wetlands have a moderate level of functions (scoring between 30 and 50 points under the Department of Ecology’s rating system).

4. Category IV wetlands have a relatively low level of functions (scoring less than 30 points under the Department of Ecology’s rating system).

C. Illegal Modifications. Wetland rating categories shall not change due to illegal modifications made by the applicant or with the applicant’s knowledge. [Ord. 1192 § 1 (Exh. A), 2022; Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.270)), 2010.]

18.90.280 Wetland exemptions.

All isolated Category IV wetlands less than 500 square feet that are not associated with riparian areas or buffers, not part of a wetland mosaic, and do not contain habitat identified as essential for local populations of priority species identified by the Washington Department of Fish and Wildlife or species of local importance identified in RMC 18.90.210 are exempt from provisions contained in this article. All such wetlands between 500 and 1,000 square feet are exempt from the normal mitigation sequencing process (i.e., can be filled), if impacts are fully mitigated based on provisions in RMC 18.90.310. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.280)), 2010.]

18.90.290 Wetland buffers.

A. Standard Buffer Widths. Wetland buffers shall be measured perpendicular from the wetland boundary as surveyed in the field, with the following standard widths:

1. Category I and II Wetlands. Buffer widths for Category I and Category II wetlands are based on habitat function scores (derived from the Washington State Wetland Rating System for Eastern Washington (Ecology Publication No. 04-06-015, or as revised and approved by Ecology)), in accordance with the following graduated scale:

Points for Habitat from Wetland Rating Form	≤ 21	22	23	24	25	26	27	28	29	30	≥ 31
Wetland Buffer Width	100	120	140	160	180	200	220	240	260	280	300

2. Category III. Wetland buffer widths for Category III wetlands are based on habitat function scores (derived from the 2004 Wetland Rating System for Eastern Washington) in accordance with the following graduated scale:

Points for Habitat from Wetland Rating Form	≤ 21	22	23	24	25	≥ 26
Wetland Buffer Width	100	120	140	160	180	200

3. Category IV. The wetland buffer width for Category IV wetlands shall be 70 feet.

B. Increased Buffer Widths. When a larger buffer is necessary to protect wetland or other critical area functions and values based on site-specific characteristics, the planning official shall require increased buffer widths in accordance with the recommendations of a qualified professional. Examples include when a wetland buffer provides habitat for a species protected under RMC 18.90.210 or 18.90.220, or if the buffer or adjacent uplands are susceptible to erosion and standard erosion control measures may not prevent adverse impacts to the wetland.

C. Buffer Reductions Incentives. Standard buffer widths may be reduced under the following conditions; provided, that functions of the post-project wetland are equal or greater after use of these incentives:

1. Lower Impact Land Uses. Except in the urban forest and watershed zones, standard buffer widths may be reduced up to 15 percent in conjunction with the approval of measures that will result in no net loss or a net gain in ecological function. This may include application of measures to minimize the impacts of the land use adjacent to the wetlands such as infiltration of storm water, retention of native vegetation and soils, direction of noise and light away from the wetland, and other measures that may be suggested by a qualified wetlands professional. The development of these measures and their review by the city, which may include referral to independent qualified professionals, shall be at the applicant’s expense. If proposed future land uses are more intense, they are not eligible to maintain this reduction.

2. Restoration. Buffer widths may be reduced up to 35 percent if the buffer is restored or enhanced from a preproject condition that is disturbed (e.g., dominated by invasive species), so that functions of the post-project wetland and buffer are equal or greater. The restoration plan must meet requirements in RMC 18.90.100 for a mitigation plan and RMC 18.90.300 for a critical area report.

3. Combined Reductions. Buffer width reductions allowed under subsections (B)(1) and (2) of this section may be added. However, the total reduction may be no more than 25 percent when the planning official determines that the soils or other conditions of a wetland are particularly sensitive to nutrient or pollutant loading.

D. Buffer Averaging. Except in the urban forest and watershed zones, the planning official shall have the authority to average buffer widths on a case-by-case basis, where a qualified wetlands professional demonstrates, as part of a critical area report, that all of the following criteria are met:

1. The total area contained in the buffer after averaging is no less than that contained within the buffer prior to averaging;

2. Decreases in width are generally located where wetland functions may be less sensitive to adjacent land uses and increases are generally located where wetland functions may be more sensitive to adjacent land uses, to achieve no net loss or a net gain in functions; and

3. The averaged buffer, at its narrowest point, shall not result in a width less than 75 percent of that allowed under other provisions of this section; provided, that minimum buffer widths shall never be less than 50 feet for Category I, Category II and Category III wetlands and 25 feet for Category IV wetlands.

4. Effect of Mitigation. If wetland mitigation occurs such that the rating of the wetland changes, the requirements for the category of the wetland after mitigation shall apply.

E. Signage. Signs shall identify post-project wetland buffers as critical areas or native growth protection areas, in accordance with RMC 18.90.140(B).

F. Allowed Uses. The following uses may be permitted within a wetland buffer, provided they are not prohibited by any other applicable law and they are conducted in a manner so as to minimize negative impacts to the buffer and adjacent wetland:

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

2. Passive recreation facilities designed and in accordance with an approved critical area report, including:

a. Wildlife viewing structures; and

b. Walkways and trails, provided pathways minimize adverse impacts on water quality. They should generally be parallel to the perimeter of the wetland, located in the outer 25 percent of the wetland buffer area, and avoid removal of significant trees. They must be limited to pervious surfaces no more than four feet in width. Raised boardwalks utilizing nontreated pilings may be acceptable.

3. Storm water management facilities, limited to storm water dispersion outfalls and bioswales, may be allowed within the outer 25 percent of the buffer of Category III or IV wetlands only; provided, that:

a. No other location is feasible; and

b. Their location, with mitigation, will not degrade the functions or values of the wetland. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.290)), 2010.]

18.90.300 Wetland critical area reports.

If required by the planning official in accordance with RMC 18.90.070(B), a critical area report for wetlands shall meet requirements of this section. The report and its review by the city, which may include referral to independent qualified professionals, shall be at the applicant’s expense. The report shall include the following components:

A. The name and contact information of the applicant, a description of the proposal, and identification of the permit requested;

B. A site plan for the project containing the following:

1. Maps (to scale) depicting delineated and surveyed wetlands and required buffers on site, as well as buffers for off-site wetlands that extend onto the project site or that might be impacted by the proposed activity, the proposed development, grading and clearing limits, and areas of proposed impacts to wetlands and/or buffers (including square footage estimates).

2. A depiction of the proposed storm water management facilities and outlets (to scale) for the development, including estimated areas of intrusion into the buffers of any critical areas.

C. A written report for the project containing the following:

1. A vicinity map for the project;

2. Identification of all the local, state, and/or federal wetland-related permit(s) required for the project;

3. The dates, names, and qualifications of the persons preparing the report and documentation of any fieldwork performed on the site, including field data sheets for delineations, function assessments, baseline hydrologic data, etc.;

4. A description of the methodologies used to conduct the wetland delineations, function assessments, or impact analyses, including references and all assumptions made and relied upon;

5. For all wetlands on the subject property and all off-site wetlands that could be impacted by the proposed action (using best available information if adjacent property access is denied) provide the following: hydrogeomorphic and Cowardin classification; characterization of vegetation, soils, and hydrology indicators; wetland rating (RMC 18.90.270); wetland buffer width (RMC 18.90.290); and, wetland acreage estimates;

6. Description of the proposed activity and assessment of cumulative impacts to wetlands and buffers from development of the site, including a discussion of the potential impacts to the wetland(s) associated with anticipated hydroperiod and water quality alterations;

7. Evaluation of existing and post-project functions of the wetland and adjacent buffer using a functional assessment method recognized by local or state agency staff (e.g., Methods for Assessing Wetland Functions, Ecology Publication No. 99-115) and including all data sheets and references for the method used; and

8. An analysis of site development alternatives, including a no development alternative.

D. If the proposed development would have significant adverse impacts to wetlands or their buffers, the critical area report must include a mitigation plan consistent with RMC 18.90.310.

E. Unless otherwise provided, a critical area report may be supplemented by or composed, in whole or in part, of any reports or studies required by other laws and regulations or previously prepared for and applicable to the development proposal site, as approved by the planning official. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.300)), 2010.]

18.90.310 Wetland compensatory mitigation.

A. All significant adverse impacts to wetlands and buffers as determined by the planning official shall be mitigated in accordance with the standards in RMC 18.90.090 and 18.90.100 and this section, and with reference to the Department of Ecology’s Guidance on Wetland Mitigation in Washington State, Part 2 (Ecology Publication No. 04-06-013B) and Appendix 8-C of the Department of Ecology’s Wetlands in Washington – Volume 2: Guidance for Protecting and Managing Wetlands (Ecology Publication No. 05-06-008), or updated guidance by Ecology.

B. If impacts to wetlands are unavoidable, mitigation to achieve compensation for wetland functions shall be approached in the following order of preference:

1. Reestablishment of natural or historic functions to a former wetland, through restoration of physical, chemical or biological processes (e.g., removing fill, plugging ditches, breaking drain tiles, breaching dikes, etc.).

2. Rehabilitation of natural or historic functions of a degraded wetland through restoration of physical, chemical or biological processes (e.g., removing fill, plugging ditches, breaking drain tiles, breaching dikes, etc.).

3. Creation of wetlands on disturbed upland sites, where the post-project hydrologic regime can demonstrably support the proposed wetland plant community.

4. Enhancement of vegetation or other characteristics of a wetland site to improve specific functions, such as filtration of pollutants or wildlife habitat.

5. Preservation or protection of a wetland that would not be adequately accomplished through existing regulations.

C. Mitigation shall be on site, where ecologically appropriate. Where this is infeasible, the applicant shall consult with the city, Yakama Indian Tribe, the Cle Elum district of the Wenatchee National Forest, the Kittitas conservation trust and the Washington State Departments of Ecology and Fish and Wildlife regarding off-site mitigation. Mitigation shall prioritize the preservation and restoration of contiguous wildlife habitat corridors to minimize the isolating effects of development on habitat areas.

D. Payment may be accepted in lieu of an off-site mitigation project. At a minimum, such payment shall be equivalent to the cost of implementing an acceptable off-site project, as estimated by a qualified professional approved by the city. The city, in consultation with the Yakama Indian Tribe, the Cle Elum district of the Wenatchee National Forest, and the Kittitas conservation trust, shall use these funds for wetland improvements it believes are in the best interest of the city and provide a greater ecological benefit than the alternative off-site project. Wetland improvements under this section are subject to the following criteria:

1. Fees will be used to find a clearly defined mitigation project;

2. The project being funded will result in an increase in acreage and function that adequately compensates for the permitted impacts;

3. The project being funded is within the same watershed as the impact;

4. There is a clear timeline for completing the mitigation project;

5. There are provisions for long-term protection and management, including mechanisms such as conservation easements, and funding for long-term management of the site; and

6. No approved mitigation bank or other form of compensatory mitigation is environmentally preferable and available.

E. It is preferred that compensatory mitigation projects be completed prior to activities that will disturb wetlands. If that is infeasible, compensatory mitigation shall be completed immediately following disturbance and prior to use or occupancy of the action or development. Construction of mitigation projects shall be timed to reduce impacts to existing fisheries, wildlife, and flora.

F. Wetland Replacement Ratios.

1. When an applicant proposes to alter a wetland, the affected wetland acreage shall be replaced through wetland restoration, creation, enhancement or preservation, according to the ratios established in the table below. The ratios apply to mitigation that is on site, timed prior to or concurrent with alteration, having a high probability of success, and in kind (i.e., losses of wetland acreage shall be replaced by creation or restoration of new acreage; degradation of wetland functions shall be replaced by restoration or enhancement of new wetland functions, etc.). Where these conditions do not hold, ratios shall be adjusted accordingly, as determined by the planning official, in consultation with the Washington Department of Ecology, the Washington Department of Fish and Wildlife and the Yakama Indian Tribe.

2. Ratios for remedial actions resulting from unauthorized alterations shall be greater than set forth in the table, as determined by the planning official.

3. Ratios in the table are based on the assumption that the wetland category, based on RMC 18.90.270(B), and hydrogeomorphic (HGM) class/subclass of the wetland proposed as compensation are the same as the category and HGM class/subclass of the wetland impacted. Ratios for projects in which the wetland category and HGM class/subclass of wetlands proposed as compensation are not the same as that of the wetland impacted will be determined on a case-by-case basis using the recommended ratios as a starting point.

Category and Type of Wetland	Creation or Reestablishment	Rehabilitation	Enhancement	Preservation
Category I – Bog, natural heritage site	Not considered possible	6:1	Case-by-case	10:1
Category I – Mature forested	6:1	12:1	24:1	24:1
Category I – Based on functions	4:1	8:1	16:1	20:1
Category II – Based on functions	3:1	6:1	12:1	20:1
Category III	2:1	4:1	8:1	15:1
Category IV	1.5:1	3:1	6:1	10:1

G. If compensatory mitigation is proposed, the wetlands critical area report must contain a mitigation plan prepared by a qualified wetlands professional, including the following information in addition to that required by RMC 18.90.100 and 18.90.300:

1. A baseline study that analyzes the existing functions of the wetland and wetland buffer, functions that will be lost, and functions after mitigation;

2. Description of how lost functions will be replaced;

3. Description of when mitigation will occur relative to project construction;

4. Provisions for adequate monitoring to ensure success of the mitigation plan. The monitoring plan shall outline the approach for monitoring construction of the mitigation project, and for assessment of the completed project, and shall include a monitoring schedule. A monitoring report shall be submitted to the city annually for a period of at least five years unless a more frequent time period is required by the planning official, and shall document successes, problems and contingency actions of the mitigation project. Monitoring activities may include, but are not limited to:

a. Establishing vegetation monitoring plots to track changes in plant species’ composition and density over time;

b. Measuring base flow rates and storm water runoff to model and evaluate hydrologic predictions;

c. Sampling fish and wildlife populations to determine habitat utilization, species abundance and diversity; and

d. Sampling surface and subsurface waters to determine pollutant loading, and changes from the natural variability of background conditions;

5. A contingency plan specifying what corrective actions will be taken should the mitigation not be successful.

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

1. The bank is certified under state law;

2. The planning official determines that the wetland mitigation bank provides appropriate compensation for the authorized impacts; and

3. The proposed use of credits is consistent with the terms and conditions of the bank’s certification.

Replacement ratios for projects using bank credits shall be consistent with replacement ratios specified in the bank’s certification. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.310)), 2010.]

Article V. Critical Aquifer Recharge Areas

18.90.320 Designation of critical aquifer recharge areas.

Critical aquifer recharge areas (CARAs) are those areas with a critical recharging effect on aquifers used for potable water. CARAs have prevailing geologic conditions associated with infiltration rates that create a high potential for contamination of groundwater resources or contribute significantly to the replenishment of groundwater. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.320)), 2010.]

18.90.330 Critical aquifer recharge areas regulated activities.

The following activities or land uses, where otherwise permitted, are subject to the requirements of this article:

A. Above or below ground storage tanks for hazardous substances or hazardous wastes.

B. Commercial, industrial, institutional or other facilities that include: automobile washers, chemical treatment storage and disposal facilities, dry cleaners, hazardous waste generators, junk yards and salvage yards, oil and gas drilling, on-site sewage systems, pesticide storage and use, petroleum transmission facilities and/or storage tanks, solid waste handling and recycling facilities, vehicle repair and services, wastewater application to land surfaces, and other activities that create a significant risk of contaminating CARAs.

C. Residential sewage disposal systems that serve two or more residences or that have a density greater than one system per acre.

D. Storm water management facilities that infiltrate the majority of water they manage. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.330)), 2010.]

18.90.340 Critical aquifer recharge areas critical area report.

A. For all regulated activities, the applicant shall submit a critical area report describing the best management practices to be used to minimize the risk of aquifer contamination. The report and its review by the city, which may include referral to independent qualified professionals, shall be at the applicant’s expense. At a minimum, these practices shall include those recommended by the Washington Department of Ecology in its 2004 Storm Water Management Manual for Eastern Washington (Publication No. 04-10-076) or future updated publications, as applicable, and shall comply with requirements in the Washington Administrative Code for the proposed activity.

B. The following general development standards shall apply to all regulated activities:

1. Floor drains shall be connected to an approved sanitary sewer system, where available;

2. Vehicle washing facilities must be self-contained and connected to an approved sanitary sewer system;

3. Underground tanks shall be installed in accordance with Chapter 173-360 WAC, Underground Storage Tanks;

4. Vehicle repair and service areas shall be conducted over impermeable pads and be located within an enclosed structure;

5. Chemicals shall be stored in a manner that is protected from the weather and be located within containment areas; and

6. Additional protective measures may be required if deemed necessary by the city.

C. The applicant shall also submit a spill prevention plan that identifies equipment being used or any structures that could fail and contaminate CARAs. The plan shall include provisions for regular inspection, repair, replacement, clean-up methods to be used, and methods to dispose of all spilled materials.

D. If the planning official determines that additional precautions may be necessary to protect against groundwater contamination, a hydrogeologic site evaluation prepared by a qualified professional may be required. The evaluation shall address some or all of the following, as specified by the planning official:

1. Hydrogeologic Setting.

a. Description of the geologic setting of the site, illustrated with geologic and soil maps;

b. Discussion of geologic features which may influence groundwater movement, such as faults, landforms, etc.;

c. Description of the occurrence and movement of groundwater in the area, including a general discussion of aquifer recharge and discharge, depth of groundwater and groundwater flow patterns; and

d. General discussion of groundwater quality in the area.

2. Site-Specific Hydrogeologic Data.

a. Scaled map showing the location of wells (in use or inactive) and springs within 1,000 feet of the site or as required by the planning official;

b. Depth to groundwater layer in the immediate vicinity;

c. Hydrogeological cross-sections through the site and immediate vicinity with references to information used to prepare the cross-sections;

d. Description of groundwater movement beneath the site with considerations for the following:

i. Areal distribution, stratification and hydraulic conductivity of the water-bearing formations;

ii. Probable migration pathways for contaminants;

iii. An estimate of the probable times of travel through the soil horizontally and vertically from a potential contaminant source;

e. Description of how the contaminants of concern will be attenuated within the saturated zone; and

f. Estimate of the quantity and/or quality of water recharged to the saturated zone under anticipated operation.

E. A mitigation plan shall be required to address groundwater impacts identified in the hydrogeologic site evaluation, consistent with RMC 18.90.090 and 18.90.100. The planning official may require that the plan include monitoring, process controls, remediation and discussion of alternatives. [Ord. 1060 §§ 5, 6, 2010; Ord. 1059 § 2 (Exh. A (12.90.340)), 2010.]