1. A description of the proposed project;

2. Payment of fees in accordance with IMC 18.800.340;

3. Site information, including site plans, vicinity maps, and other information required for a development permit or land use permit application;

4. The environmental checklist; and

5. If, after review of the environmental checklist, the responsible official determines that there is insufficient information to make a threshold determination, then additional information is required before the application will be determined complete.

1. Require the applicant to provide more information on subjects in the checklist;

2. The City makes its own further study;

3. The City will consult with other agencies, requesting information on the proposal’s potential impacts which lie within other agencies’ jurisdiction or expertise; or

4. Decide that all or part of the action or its impacts are not sufficiently definite to allow environmental analysis and commit to timely, subsequent environmental analysis, consistent with WAC 197-11-055 through 197-11-070.

1. The applicant may request an additional 30 days for the threshold determination.

2. The City will normally complete a threshold determination on actions where the applicant recommends in writing that an EIS be prepared, because of the probable significant adverse environmental impacts described in the application, within 30 working days of receiving a completed application.

3. The responsible official will normally respond to a request for early notice made pursuant to IMC 18.800.190 within 10 working days.

4. The threshold determination will normally be made within 90 working days of receipt of an amended or clarified project proposal, environmental checklist or permit application. (Ord. 3019 § 1 (Exh. A), 2023).

1. For a single-family residential project up to 10 units.

2. For a multifamily residential project up to 10 units.

3. For an office, school, commercial, recreational, service, storage building, or parking facility project up to 10,000 square feet.

1. Determine whether the applicable regulations require studies that adequately analyze all of the project permit application’s specific probable adverse environmental impacts;

2. Determine if the applicable regulations require measures that adequately address such environmental impacts;

3. Determine whether additional studies are required and/or whether the project permit application should be conditioned with additional mitigation measures;

4. Provide prompt and coordinated review by government agencies and the public on compliance with applicable environmental laws and plans, including mitigation for specific project impacts that have not been considered and addressed at the plan or development regulation level;

5. Review and document consistency with Comprehensive Plan and this Code.

1. The impacts have been avoided or otherwise mitigated below a probable significant adverse impact; or

2. The City has designated as acceptable certain levels of service, land use designations, development standards or other land use planning required or allowed by Chapter 36.70A RCW.

1. Are designated planned actions by an ordinance or resolution adopted by the City;

2. Have had the significant impacts adequately addressed in an EIS prepared in conjunction with:

3. Are subsequent or implementing projects for the proposals listed in subsection (B)(2)(b) of this section;

4. Are located within an urban growth area, as defined in RCW 36.70A.030;

5. Are not essential public facilities, as defined in RCW 36.70A.200; and

6. Are consistent with the City’s Comprehensive Plan adopted under Chapter 36.70A RCW.

1. The City may not give authorization for:

2. The City may withhold approval of an exempt action that would lead to modification of the physical environment, when such modification would serve no purpose if the nonexempt actions were not approved; and

3. The City may withhold approval of a series of exempt actions, physically or functionally related to each other, and that together may have a probable significant adverse environmental impact;

4. The City may withhold approval of exempt actions that would lead to substantial financial expenditures by a private applicant when the expenditures would serve no purpose if the nonexempt actions were not approved.

1. State on the first page of the notice of application that it expects to issue a DNS for the proposal, and that:

2. List in the notice of application the conditions being considered to mitigate environmental impacts, if a mitigated DNS is expected; and

3. Comply with the requirements for a notice of application and public notice in RCW 36.70B.110.

1. Issue a DNS or mitigated DNS with no comment period using the procedures in subsection E of this section;

2. Issue a DNS or mitigated DNS with a comment period using the procedures in subsection E of this section, if the responsible official determines a comment period is necessary;

3. Issue a DS; or

4. Require additional information or studies prior to making a threshold determination.

1. Follow submission of a permit application and a complete application for a threshold determination as provided in IMC 18.800.080; and

2. Precede the City’s actual threshold determination for the proposal.

1. State whether the City currently considers issuance of a DS likely and, if so, indicate the general or specific areas of concern that are leading the City to consider a DS; and

2. State that the applicant may change or clarify the proposal to mitigate the indicated impacts, and may revise the environmental checklist and/or permit application as necessary to reflect the changes or clarifications.

3. When an applicant submits a changed or clarified proposal, along with a revised environmental checklist, the City must base its threshold determination on a changed or clarified proposal.

1. The applicant’s proposed mitigation measures, clarifications, changes, or conditions must be in writing and must be specific.

2. Mitigation measures that justify issuance of a MDNS may be incorporated by reference to agency staff reports, studies, or other documents.

1. Notice of Threshold Determination or EIS. Whenever the City issues a threshold determination or EIS requiring public notice, the City must give public notice of the determination or the availability of the environmental documents and whether any public hearing will be held in accordance with IMC 18.204.120, Distribution of public notices.

1. Such conditions are necessary to mitigate specific adverse environmental impacts clearly identified in an environmental document prepared pursuant to this chapter; and

2. Such conditions are in writing; and

3. Such conditions are reasonable and capable of being accomplished; and

4. The City has considered whether other local, State, or Federal mitigation measures applied to the proposal are sufficient to mitigate the identified impacts; and

5. Such conditions are based on one or more policies in the SEPA policies (IMC 18.800.300) and cited in the permit, approval, license, or other decision document.

1. A finding is made that approving the proposal would result in probable significant adverse environmental impacts that are identified in a final EIS or final supplemental EIS; and

2. A finding is made that the mitigation measures are insufficient to mitigate the identified impact; and

3. The denial is based on one or more policies identified in SEPA policies (IMC 18.800.300) and identified in writing in the decision document. (Ord. 3019 § 1 (Exh. A), 2023).

1. A SEPA appeal is limited to review of a final threshold determination and final EIS.

2. No appeal of the intermediate steps under SEPA such as lead agency determination, scoping, or a draft EIS adequacy is allowed.

3. Only one administrative appeal of a threshold determination or of the adequacy of an EIS is allowed; successive administrative appeals on these issues are not allowed.

1. The appeal of a determination of significance;

2. An appeal of a procedural determination made by an agency when the agency is a project proponent, or is funding a project, and chooses to conduct its review under SEPA, including any appeals of its procedural determinations, prior to submitting an application for a project permit; and

3. An appeal of a procedural determination made by an agency on a nonproject action.

1. Threshold Determination. For every environmental checklist the City reviews as lead agency, the City must collect a fee from the proponent of the proposal prior to undertaking review. The time periods provided by this chapter for making a threshold determination do not begin to run until payment of fees are collected by the City. For any complex review requiring staff time in excess of 10 hours, the City may charge an hourly rate for the additional time.

2. Environmental Impact Statement.

1. The provisions of the Washington State Growth Management Act (GMA) as codified under Chapter 36.70A RCW;

2. The consultation of State and Federal agencies and other qualified professionals; and

3. The goals and policies of the City of Issaquah’s Comprehensive Plan.

1. Protect members of the public and public resources and facilities from injury, loss of life, property damage, or financial losses due to flooding, erosion, landslides and seismic induced ground disturbance, abandoned coal mine subsidence, and steep slope failures;

2. Protect unique, fragile, and valuable elements of the environment, including wildlife and its habitat;

3. Prevent the loss of wetland and watercourse function and acreage, and strive for a gain over present conditions;

4. Mitigate unavoidable impacts to environmentally critical areas by regulating alterations in and adjacent to critical areas;

5. Prevent cumulative adverse environmental impacts to water availability, water quality, wetlands, and streams;

6. Minimize erosion potential;

7. Avoid alteration to wetland hydrology that causes either short- or long-term changes in native vegetational composition, soils characteristics, nutrient cycling, or water chemistry;

8. Protect the public trust as to navigable waters and aquatic resources;

9. Protect critical aquifer recharge areas by avoiding land use activities that pose potential contamination, and minimize impacts to recharge areas;

10. Meet the requirements of the National Flood Insurance Program (NFIP) and maintain Issaquah as an eligible community for Federal flood insurance benefits;

11. Balance the private rights of individual property owners with the preservation of environmentally critical areas;

12. Alert members of the public, including but not limited to appraisers, owners, potential buyers, or lessees, to the development limitations of critical areas;

13. Provide City officials with sufficient information to protect critical areas;

14. Implement the policies of the State Environmental Policy Act, Chapter 43.21C RCW, Chapter 197-11 WAC, the Issaquah Municipal Code, the City of Issaquah Comprehensive Plan, and the Shoreline Master Program; and

15. Educate the public about the long-term care of critical areas.

1. Geologically hazardous areas: coal mine hazard areas, erosion hazard areas, landslide hazard areas, seismic hazard areas, and steep slope areas;

2. Wetlands;

3. Streams;

4. Fish and wildlife habitat conservation areas;

5. Critical aquifer recharge areas; and

6. Areas of special flood hazard are regulated under Chapter 16.36 IMC.

1. Commercial or residential building permits or other construction actions;

2. Right-of-way construction permits; grading and clearing permits;

3. Right-of-way permits;

4. Shoreline conditional use permits;

5. Shoreline environmental redesignations;

6. Shoreline substantial development permits;

7. Shoreline variances;

8. Site development permits and conditional use permits;

9. Subdivisions and short subdivisions;

10. Utility and other use permits;

11. Variances;

12. Zone reclassifications; or

13. Any subsequently adopted permits or required approvals not expressly exempted by this chapter.

1. The approximate location and estimated extent of critical areas in the City are displayed on the maps below, which will be referred to as the Issaquah critical areas map folios:

2. Critical areas not shown on these maps may still exist in the City. Unmapped critical areas are protected under all the provisions of this Code. Not all critical areas are shown on the Issaquah critical areas map folios. Thus, it is the responsibility of property owners and applicants to verify actual presence or absence of a critical area or critical area buffer based on the definitions in this chapter.

3. If any critical area designation shown on the maps conflicts with the criteria set forth in this chapter, the criteria will control.

4. Issaquah critical areas map folios may be amended as new information concerning critical area locations, such as soils, hydrology, flooding, plants, and wildlife, become available.

1. These critical areas standards apply in addition to zoning and other regulations adopted by the City. When any provision of the Issaquah Municipal Code, Shoreline Master Program, or this Code conflicts with this chapter, the provisions apply that provide the most protection to the critical areas, as determined by the Director. If two or more critical areas are present at the same location, the provisions of this chapter which provide the greater protection apply.

2. The provisions of this Code prevail over any inconsistent ordinance.

3. The provisions of this chapter apply to all forest practices over which the City has jurisdiction, pursuant to Chapter 76.09 RCW, WAC Title 222, and any memorandum of understanding between the Washington Department of Natural Resources and the City. In addition, this chapter applies to all property which has been cleared and/or graded without an approved forest practice application and which is subsequently proposed for development.

4. The City of Issaquah Shoreline Master Program (SMP) contains rules and regulations governing lakes, streams, and wetlands.

5. Development proposals located within areas of special flood hazard must comply with Chapter 16.36 IMC, Areas of Special Flood Hazard.

1. Removing, excavating, grading, or dredging of soil, sand, gravel, minerals, organic matter, or material of any kind;

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

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

4. Driving of pilings;

5. Placing of obstructions;

6. Constructing, reconstructing, demolishing, or altering the size of any structure;

7. Altering vegetation through clearing, harvesting, shading, intentional burning, or planting that would alter the character of a regulated wetland; provided, that these activities are not part of a forest practice governed under Chapter 76.09 RCW and its rules; or

8. Activities that result in a significant change of water temperature, a significant change of physical or chemical characteristics of wetlands water sources, including quantity, or the introduction of pollutants. (Ord. 3019 § 2 (Exh. B), 2023).

1. Emergency activities necessary to prevent an immediate threat to public health, safety, or property, and that require remedial or preventive action within too short a time frame to comply with the requirements of this chapter. Emergency actions are required to use reasonable methods to address the emergency with the least possible impact to the critical area. Once the immediate threat has been addressed, any adverse impacts must be minimized and mitigated to meet the intent and purpose of this chapter. The person or agency undertaking such action must notify the Director of the existence of the emergency and emergency actions taken within one working day following commencement of the emergency activity. The Director will determine if such an action constitutes an emergency action, if the action taken was beyond the scope of the exemption, and shall require necessary permits after the fact, including any restoration or mitigation.

2. Normal and routine maintenance of existing irrigation and drainage ditches, including, but not limited to, vegetation control, and removal of sediment and debris. However, the City must be notified by providing a written notice to the Planning Manager, Department of Community Planning and Development, prior to such activities occurring. This exception does not apply to any ditches used by salmonids or those that require approval from the Washington State Department of Fish and Wildlife.

3. Public water, electric and natural gas distribution, public sewer collection, cable communications, telephone utility, and related activities undertaken pursuant to City-approved best management practices are exempt from this chapter as follows:

4. Maintenance and repair of public or private improved roadways or public or private improved parks or trails are exempt from this chapter.

5. Public agency development proposals whose construction contract was awarded before the effective date of the ordinance codified in this chapter are exempt; provided, that any regulation in effect at the time of such award applies to such proposal, except for the provisions established in IMC 18.802.050.

6. Routine stream maintenance by a public entity which has been approved through the SEPA review process and by the Washington State Department of Fish and Wildlife (WDFW).

7. Steep slopes may be used for approved surface water conveyance in accordance with the City’s adopted surface water regulations. Installation techniques must minimize disturbance to the slope and vegetation.

8. Alterations to erosion, landslide, and steep slope critical areas may be allowed for mineral resource and extraction activities, processing, facilities, and related uses in existence prior to August 2, 1999, and performed not less than once every 12 months thereafter.

9. Forest practices regulated and conducted in accordance with the provisions of Chapter 76.09 RCW and forest practices regulations, WAC Title 222, are exempt, except for conversions to nonforestry uses.

10. Minor site investigation work that does not include use of heavy equipment or native vegetation removal. Work necessary for land use permit submittals, such as surveys, soil logs, percolation tests, and other related activities, can be an allowed use when they do not require construction of new roads or minimum amount of excavation needed for site investigation purposes. However, any impacts to the critical area must be minimized and disturbed areas immediately restored.

11. Voluntary native revegetation and/or removal of nonnative invasive vegetation from critical areas and associated buffers is encouraged within the City of Issaquah. This includes work authorized and conducted under the City’s Green Issaquah Program. Removal of invasive species must be accomplished through the use of hand labor and/or hand-held light equipment and without the use of herbicides unless alternative methods are approved by the Department of Community Planning and Development. The Director may allow the use of herbicide by a licensed contractor with certification as needed from the Washington Department of Ecology and the Washington Department of Agriculture.

1. There is no other practical alternative to the proposed development with less impact on the critical areas;

2. The application of the critical area regulations would unreasonably restrict the ability to provide utility services to the public;

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

4. The proposal attempts to protect and mitigate impacts to the critical area functions and values consistent with the best available science; and

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

1. Class 1 streams or buffers covered by the City’s Shoreline Management Program;

2. Category I or II wetlands or their buffers with Federal or State threatened or endangered plant species; and

3. Category I or II wetlands or their buffers which provide critical or outstanding actual habitat for the following unless the applicant clearly demonstrates that there would be no adverse impact on critical or outstanding actual habitat for:

1. Avoid impacts altogether by not taking a certain action or parts of an action;

2. 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;

3. Rectify impacts by repairing, rehabilitating or restoring the affected environment;

4. Compensate for the impact by replacing, restoring, creating, enhancing or providing substitute resources or environments;

5. Monitor the impact and the compensation projects and taking appropriate corrective measures.

1. Coal mine hazard areas: defined at IMC 18.102.070.

2. Erosion hazard areas: defined at IMC 18.102.090.

3. Landslide hazard areas: defined at IMC 18.102.160.

4. Seismic hazard areas: defined at IMC 18.102.230.

5. Steep slope hazard areas: defined at IMC 18.102.230.

6. Peat settlement prone areas: defined at IMC 18.102.200. (Ord. 3019 § 2 (Exh. B), 2023).

1. Declassified. Areas underlain by or adjacent to coal mines having a depth of greater than 300 feet or where engineering analysis determines the workings are known to have collapsed and/or pose no risk of a sinkhole or trough subsidence (calculated tilt less than 1:350, strain less than 0.003);

2. Moderate Mine Hazard. Areas underlain by or adjacent to coal mines where engineering analysis demonstrates that a risk of trough subsidence exists such that future collapse of workings can result in tilt and strain below the subject property exceeding 1:350 and 0.003 respectively. Moderate mine hazard areas typically include areas underlain by workings 300 feet or less in depth or with overburden-cover-to-seam thickness ratios of less than 10:1, depending on the inclination of the seam. Trough subsidence risk to structures and infrastructure in moderate mine hazard areas can be mitigated by implementing special structural engineering, civil engineering, and architectural measures;

3. Severe Mine Hazard. Areas that pose a significant risk of property damage due to catastrophic ground surface collapse, including sinkhole formation, or severe trough subsidence. Severe mine hazard areas typically include, but are not limited to, areas of unmitigated openings such portals, adits, shafts, sinkholes, improperly mitigated sinkholes or openings, or areas underlain by coal mine workings at a depth of less than 150 feet.

1. Age. The age of a landslide is classified as follows:

2. Material and Movement. Landslides are described using a combination of terms describing material and movement, such as rockfall and debris flow. Landslides may also be a complex failure with more than one type of movement, such as rotational slide debris flow. Classification of a landslide requires the applicant to identify both the materials and the movements involved.

1. Earthquake Induced Landslide Hazard Area. An area including slopes that can become unstable as a result of strong ground shaking, even though these areas may be stable under nonseismic conditions. Susceptibility of a site to seismic induced landslides will be determined by performing dynamic slope stability assessments of any slopes identified as steep slope hazard areas or landslide hazard areas in accordance with the applicable sections of the IMC. This information must be included in the applicant’s critical areas study.

2. Liquefaction Susceptible Area. An area underlain by unconsolidated sandy or silt soils (Unified Soil Classification System S or M soil types) with a shallow groundwater table capable of liquefying in response to earthquake shaking.

3. Liquefaction Induced Lateral Spreading. Lateral deformation (landslides) that form on gentle slopes or flat ground with a nearby free face (i.e., slope face or retained ground) as a result of liquefaction and have rapid fluid-like flow movement.

4. Fault Rupture Hazard Area.

1. Required Buffers.

2. Exceptions. Buffers may be removed if severe mine hazards have been remediated in accordance with the mitigation standards in IMC 18.802.190(C).

1. Required Buffers.

2. Exceptions. Buffer reductions or buffer deletions may be approved through the critical areas study review process if the risk of landslide movement can be permanently mitigated and the applicant demonstrates a factor of safety of 1.5 (static) and 1.1 (seismic) for all critical slip surfaces and topographic sections.

1. Building Restrictions.

2. Mitigation.

1. Required Buffers.

2. Exceptions.

3. Steep Slope Buffer Reduction Requests. A request for a steep slope buffer reduction is reviewed through the critical areas study review process, according to the following assessment standards:

1. There are no coal mine hazard related development standards for development within declassified mine hazard areas.

2. Development is not permitted within a severe mine hazard area or buffers associated with a severe mine hazard area, unless an applicant demonstrates through a critical areas study that the severe mine hazard can be remediated to a degree that the risk of surface collapse is no longer present.

3. Development is permitted in moderate mine hazard areas if the potential damage resulting from the deformations (tilt and strain), as calculated and presented in the critical area study, can be mitigated in all planned structures and utilities.

1. No construction is permitted over coal mine waste material unless specific design and construction criteria are developed by a qualified geotechnical professional to mitigate the potential impacts of the coal mine waste on foundation stability and performance.

2. Construction is prohibited within 100 feet of any coal mine waste dump that shows evidence of current or past combustion.

3. Any coal mine waste dump from which springs or seeps are discharging, or which shows evidence of seasonal discharge of springs or seeps, must be removed, or regraded to expose the source of the spring or seep. The coal mine waste dump must be removed from the site or regraded, unless the stability of the coal mine waste dump can be verified by a slope stability analysis to meet the minimum requirements for static and seismic safety. All slopes in the coal waste material must remain below 2(H):1(V) and meet stability criteria.

4. All coal mine waste material in open spaces must be covered with a minimum of two feet of clean soil and must be revegetated.

1. Additions to existing single-family residences in moderate mine hazard zones. The mitigation standards for moderate mine hazard areas may be waived in the case if a mine hazard critical areas study confirms the home is located in a moderate mine hazard area.

2. Development within a severe mine hazard area may be allowed if the applicant can demonstrate that the severe mine hazard can be remediated to a degree that the risk of surface collapse is no longer present. If the site remediation to address the severe mine hazard is not sufficient to remediate the risk of trough subsidence, then the mitigation requirements for a severe mine hazard area remain and must be met. (Ord. 3019 § 2 (Exh. B), 2023).

1. Clearing in erosion hazard areas is allowed only from May 1st to October 1st.

2. Only clearing necessary to install temporary sedimentation and erosion control measures is allowed to occur prior to clearing for roadways or utilities.

3. Clearing limits for roads, sewer, water and stormwater utilities, and temporary erosion control facilities must be marked in the field and approved by the Director of the Department of Public Works or their designee prior to any alteration of existing native vegetation.

4. The authorized clearing for roads and utilities must be the minimum necessary to accomplish project-specific engineering designs and provide necessary electrical clearances.

5. Clearing of trees permitted pursuant to Chapter 18.812 IMC, Tree Preservation, regulations may occur in conjunction with clearing for roadways and utilities.

6. Retained trees, understory, and stumps may subsequently be cleared only if such clearing is a specific element of residential, multifamily, or commercial structure site plan approval. This must be carried out as a part of a vegetation management plan.

7. Hydroseeding or other erosion control methods as required in temporary erosion control plans are required.

8. All development proposals must submit an erosion control plan consistent with this section and other adopted requirements prior to receiving approval. (Ord. 3019 § 2 (Exh. B), 2023).

1. Any area with a combination of slopes greater than 15 percent and a height of 15 feet or greater and geomorphic evidence of landslide risk such as:

2. Any area with evidence of slope movement during the Holocene epoch (last 10,000 years) or is underlain by mass wastage debris of that epoch;

3. Areas mapped as landslides, mass wasting or landslide hazard areas on published geologic maps, City and County hazard maps, and Washington Department of Natural Resources online geologic map resources;

4. Any area potentially unstable as a result of rapid stream incision, stream bank erosion, or undercutting by wave action; and

5. Any area located on an alluvial fan, presently subject to or potentially subject to, inundation by debris flows or deposition of stream-transported sediments.

1. A landslide hazard area may only be altered under the following circumstances:

2. Properties that contain or are adjacent to a landslide hazard must apply buffers to all sides of the landslide in accordance with IMC 18.802.130.

3. Appropriate mitigation must be based upon a critical areas study that has been prepared by a qualified professional, peer reviewed, approved by the City, and be consistent with IMC 18.802.130(A).

4. Any alteration of a slope 40 percent or greater must meet standards for steep slope hazard areas IMC 18.802.180.

5. The following standards apply to vegetation removal or introduction in landslide hazard areas and their buffers:

1. Evaluation of site-specific subsurface conditions shows that the site is not located in a seismic hazard area; or

2. Mitigation is implemented to the greatest extent feasible and must minimize any potential adverse impacts.

1. Surface Water Management. An approved surface water conveyance facility consistent with the City’s adopted stormwater regulations is allowed to be located on a steep slope. Installation techniques must minimize disturbance to the slope and vegetation.

2. Trails. Construction of public and private trails is allowed on steep slopes if the critical areas study per IMC 18.802.400 and 18.802.410 documents no loss of buffer functions and values. The trail must adhere to the construction and maintenance standards in the U.S. Forest Service “Trails Management Handbook” (FSH 2309.18, June 1987 as amended) and “Standard Specifications for Construction of Trails” (EM-7720-102, June 1984 as amended). Trails may not be constructed of concrete, asphalt, or other impervious surfaces that contribute to surface water runoff unless such construction is necessary for soil stabilization or soil erosion prevention.

3. Utilities. Construction of public and private utility corridors is allowed on steep slopes, but must demonstrate through a critical area study that the alteration will not subject the area to the risk of landslide or erosion.

4. View Corridors. The City allows the limited trimming and limbing of vegetation on steep slopes for the creation and maintenance of views; provided, that the soils are not disturbed, plant health is not compromised, and the activity is consistent with Chapter 18.812 IMC, Tree Preservation, provided the steep slope is not located within an existing native growth protection easement (NGPE). Trimming and limbing activity shall follow best management practices and comply with the most recent version of the American National Standards Institute (ANSI) 300, Pruning Standards, for the removal and management of vegetation. Topping, or indiscriminate cuts made between branches that leave a stub used to reduce the height or crown size of an existing tree, is not an acceptable practice pursuant to ANSI 300, Pruning Standards, and is prohibited.

1. No removal of any vegetation is allowed from any steep slope hazard area or buffer except for the limited plant removal necessary for surveying or geotechnical exploration purposes and for the removal of hazardous trees, as determined by a qualified arborist in a tree study meeting the requirements of Chapter 18.812 IMC or any activity allowed by subsection B of this section.

2. On slopes disturbed by human activity or infested by noxious weeds, replacement with native species or other appropriate vegetation may be required subject to review during the critical areas study process.

1. Slopes 40 percent and steeper with a vertical elevation change of up to 20 feet may be exempted from the provisions of this section.

2. An exemption may be requested for any steep slope, created through previous, legal grading activities, to allow the steep slope to be altered as part of a development proposal. Any portion of the created steep slope that remains equal to or steeper than 40 percent following site development will be subject to the protection mechanisms for steep slopes, including buffer requirements.

3. Limited exemptions are reviewed through the appropriate land use permitting process and based on City review and acceptance of a soils report, prepared by a licensed geologist or licensed geotechnical engineer, that addresses the proposed exemption and demonstrates that the required static and seismic factors of safety for the slope are achieved. (Ord. 3019 § 2 (Exh. B), 2023).

1. Avoidance. Avoid the removal of peat. Avoid temporary construction activities and any permanent construction or filling above peat settlement prone areas. Avoid both temporary and permanent groundwater dewatering and both temporary and permanent lowering of seasonal high groundwater levels.

2. Minimize. Minimize the removal of peat. Removal of 100 cubic yards or more requires an evaluation of the geotechnical, groundwater and environmental impacts and proposed mitigation methods to minimize those impacts. (Ord. 3019 § 2 (Exh. B), 2023).

1. Mitigation of landslide hazards can be accomplished using one or more methods such as structural walls, engineered berms, regrading and permanent drainage measures.

2. Development applications that propose mitigation of landslide hazards must include a critical areas study that includes a detailed mitigation design that demonstrates how all significant risks associated with potential future slope movement have been permanently eliminated.

3. For a period determined by the applicant’s qualified professional and peer reviewed by the City’s consulting qualified professional, a wet season (October through April) monitoring period may be required after the completion of mitigation measures to demonstrate the mitigation was adequate.

1. Structures, pavement, utilities and grading may be permitted in seismic hazard areas, excluding fault rupture hazard areas, provided mitigation for the hazard has been demonstrated through engineering design.

2. Ground deformations from liquefaction settlement and lateral spreading must be mitigated to a level compatible with the structure foundation type such as spread footings and deep foundation, or ground improvement; for example, rammed aggregate piers and rigid inclusions.

3. Mitigation measures to protect slopes, utilities and pavements from damage from seismic ground deformation must be included in project designs. Expected ground deformations must be mitigated to a level that is tolerable for the soil and structure foundation system and meets the project design performance criteria.

4. Performance criteria must be established through collaboration between the applicant, the geotechnical engineer, structural engineer and approved by the City. Critical structures such as medical facilities, police and fire stations, bridges, and pipelines may require additional, site-specific, seismic analysis and design. Specific performance and design criteria will be determined through the critical area study review process, including evaluation of mitigation.

1. The decision of whether to permit construction directly over a moderate or severe mine hazard area that has been mitigated will be made on a case-by-case basis based on the type of mitigation and the proposed construction.

2. Hazard mitigation must be performed by or under the direction of a qualified professional. Any previously unidentified hazards found during any development activities must be immediately reported to the City.

1. Follow sequence of avoidance first. If minimizing peat removal is proposed, provide design options that allow peat to remain in place and mitigate environmental and physical impacts such as ground settlement or changes in seasonal high groundwater level and groundwater recharge. Peat removal should be considered a last resort and will be permitted only when a geotechnical critical areas report has demonstrated that other options are not technically feasible and the impact to the environment is not significant. (Ord. 3019 § 2 (Exh. B), 2023).

1. Water quality protection and enhancement;

2. Fish and wildlife habitat;

3. Food chain support;

4. Flood storage, conveyance and attenuation;

5. Groundwater recharge and discharge;

6. Erosion control;

7. Wave attenuation;

8. Carbon sequestration;

9. Historical and archaeological and aesthetic value protection; and

10. Recreation. (Ord. 3019 § 2 (Exh. B), 2023).

1. Category I wetlands score between 23 and 27 points. They are unique and rare, more sensitive to disturbance than most wetlands, and relatively undisturbed with ecological attributes that would be impossible to replace within a human lifetime. Category I wetlands are:

2. Category II wetlands score between 20 and 22 points. Category II wetlands are:

3. Category III wetlands score between 16 and 19 points. They have generally been disturbed in some ways and are often less diverse or more isolated from other natural resources in the landscape, and can often be adequately replaced with a well-planned mitigation project. Category III wetlands are:

4. Category IV wetlands score between nine and 15 points. They have the lowest level of functions and are often heavily disturbed. (Ord. 3019 § 2 (Exh. B), 2023).

1. Low-impact land uses do not require substantial mitigation in order to alleviate adverse impacts, and include:

2. Moderate-impact land uses require some degree of mitigation in order to alleviate adverse impacts, and include:

3. High-impact land uses require substantial mitigation to alleviate adverse impacts, and include the following uses:

1. Bogs.

2. Wetlands of High Conservation Value.

3. Wetlands With a Habitat Score of Eight to Nine.

4. Wetlands With a Water Quality Score of Eight to Nine and a Habitat Score of Less Than Six.

1. More than 25 percent of the buffer area is covered by nonnative and/or invasive plant species; or

2. Tree and/or shrub vegetation covers less than 25 percent of the buffer area and the wetland buffer has a slope less than 25 percent.

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

2. Where the horizontal length of the slope extends beyond the minimum wetland buffer, the wetland buffer is extended 25 feet beyond the minimum wetland buffer for that wetland category.

3. The Director may recommend wetland buffer averaging in instances where it will provide additional resource protection; provided, that the total area on site contained in the buffer remains the same. (Ord. 3019 § 2 (Exh. B), 2023).

1. The corridor is not located in a wetland or buffer used by species listed as endangered or threatened by the State or Federal government or containing critical or outstanding actual habitat of those species;

2. Consider alternative construction timing to minimize impacts in areas with heron rookeries or raptor nesting trees;

3. The corridor alignment including, but not limited to, any allowed maintenance roads may not encroach into the wetland buffer at any location by more than 25 percent of the standard wetland buffer width, per IMC 18.802.220;

4. Corridor construction and maintenance protects the wetland and buffer and is aligned to avoid cutting trees greater than 12 inches in diameter at breast height, when practical, and consistent with Chapter 18.812 IMC, Tree Preservation;

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

6. The corridor is revegetated with appropriate King County lowlands native planting at preconstruction densities or greater immediately upon completion of construction or as soon thereafter as possible, and the sewer utility ensures that such vegetation is established for at least five years;

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

8. The width of any necessary parallel road providing access for maintenance is as small as possible, but not greater than 15 feet, and the location of the road is within the utility corridor on the side away from the wetland.

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

2. The dumping, discharging, or filling with any material;

3. The draining, flooding, or disturbing of the water level or water table;

4. The driving of pilings;

5. The placing of obstructions or fences;

6. The construction, reconstruction, demolition, or expansion of any structure;

7. The destruction or alteration of wetlands vegetation through clearing, grubbing, harvesting, shading, intentional burning, or planting of vegetation that would alter the character of a regulated wetland; provided, that these activities are not part of a forest practice governed under Chapter 76.09 RCW and its rules;

8. Activities that result in a significant change of water temperature, a significant change of physical or chemical characteristics of wetlands water sources, including quantity, or the introduction of pollutants;

9. Any development or construction activity not specifically authorized as an allowed activity in this subsection A;

10. Restoration or enhancement projects; or

11. Introduction into any wetland area or associated buffers of any vegetation or wildlife that is not indigenous to the Puget Sound lowlands unless authorized by the State of Washington or a Federal license or permit.

1. Temporary, low-impact, passive recreation-related land uses such as nonpermanent wildlife watching blinds, short-term scientific or educational activities; or

2. Construction of public and private trails may be allowed in wetland buffers provided a critical areas study per IMC 18.802.400 and 18.802.420 documents no loss of buffer functions and values; or

3. Flood conveyance compensatory storage, where there is no other feasible alternative, where appropriate restoration is included, and where wetland hydrology or vegetation will not be significantly impacted; or

4. Stormwater low-impact development and vegetative flow paths from level spreaders may be located in the outer 25 percent of the wetland buffer only if the applicant demonstrates that no feasible alternative location exists, the project will not adversely affect the function or values of the wetland or its buffer, and a wetland hydroperiod impact analysis for facilities proposing discharge directly or indirectly to Category I, II, or III wetland is provided. The discharge must meet the clean water standards of Chapter 90.48 RCW and Chapters 173-200 and 173-201A WAC as amended and may not adversely affect wetland hydrology. Water quality monitoring may be required.

1. Limiting the degree or magnitude of the regulated activity;

2. Limiting the implementation of the regulated activity;

3. Using appropriate and best available technology;

4. Taking affirmative steps to avoid or reduce impacts;

5. Sensitive site design and siting of facilities and construction staging areas away from regulated wetlands and their buffers;

6. Involving resource agencies, such as the Department of Fish and Wildlife, the Army Corps of Engineers, or tribal governments, early in site planning;

7. Providing protective measures such as siltation curtains, hay bales and other siltation prevention measures, scheduling the regulated activity to avoid interference with wildlife and fisheries rearing, resting, nesting or spawning activities;

8. Prohibiting the intentional introduction of nonnative vegetation, except in the case of an approved nonnative street tree; and

9. Providing preventative measures for soil erosion such as inspections and a monitoring plan.

1. Lights must be directed away from the wetland. Lighting levels must meet the outdoor lighting standards for spillover into critical areas, per Chapter 18.610 IMC, Outdoor Lighting.

2. Activities that generate noise must be located away from the wetland, or noise impacts must be minimized through design or insulation techniques.

3. Toxic runoff from new impervious surface area must be directed away from wetlands.

4. Treated stormwater runoff may be allowed into wetland buffers, pursuant to IMC 18.802.220(C) and consistent with the Department of Ecology Guidance on Wetland Mitigation in Washington State, Part 1: Agency Policies and Guidance, April 2021, or as revised.

5. Use of pesticides, insecticides, and fertilizers within 150 feet of a wetland boundary must adhere to the best management practices set forth in Chapter 13.29 IMC, Groundwater Quality Protection Standards, to prevent impacts to water quality and water supply.

6. The outer edge of the wetland buffer must be planted with dense, armored vegetation (examples include native roses, Oregon grape) and/or fencing to limit pet and human disturbance. Fencing may be split rail or similar, subject to Director approval. (Ord. 3019 § 2 (Exh. B), 2023).

1. The following replacement ratios apply to mitigation that is in-kind, on site, the same wetland category, timed prior to or concurrent with alteration, and has a high probability of success. The first number specifies the acreage of required wetlands to be created, reestablished, rehabilitated, or enhanced and the second number specifies the acreage of existing wetlands proposed for permanent alteration.

2. In order to maintain no net loss of wetland acreage the following ratios shall apply to creation, reestablishment, rehabilitation, and enhancement of wetlands. These ratios do not apply to the use of credits from a State certified wetland mitigation bank or in-lieu fee program which are determined by the bank or in-lieu fee administrators. An applicant proposing preservation or enhancement should also provide a credit-debit analysis as outlined in the Department of Ecology’s Interagency Joint Guidance on Wetland Mitigation in Washington State, as revised.

3. Mitigation ratios may be increased for remedial actions. The Director may increase the required mitigation ratio under the following circumstances:

1. Scientific problems such as exotic vegetation and changes in watershed hydrology make implementation of in-kind compensation impossible; or

2. Out-of-kind replacement will best meet identified regional goals (e.g., replacement of historically diminished wetland types). “Out-of-kind” means replacement of wetlands with substitute wetlands whose characteristics (vegetative class, functions, and values) do not closely approximate those destroyed or degraded by a regulated activity.

1. Mitigation projects must be completed prior to or concurrent with activities that will disturb wetlands, and in all cases prior to certificate of occupancy for the associated project.

2. Construction of compensation projects must be timed to reduce impacts to existing wildlife and flora.

1. Wetland Mitigation Banking or In-Lieu Fee Program. The City must consider replacement or enhancement of unavoidable adverse impacts to wetlands caused by development activities through purchasing credits from a State or King County certified wetland mitigation bank (Chapter 173-700 WAC); or in-lieu fee program, in advance of authorized impacts in accordance with the Federal Mitigation Rule (33 CFR Part 332.3(b)).

2. When mitigation through a State approved bank or in-lieu fee program is not feasible or appropriate on-site compensation must be provided except where the applicant can demonstrate that:

3. When mitigation cannot be provided on site, mitigation must be provided in the immediate vicinity of the permitted activity on property owned or controlled by the applicant, such as an easement, provided such mitigation is beneficial to the wetland or wetland buffer and associated resources and must occur within the same watershed as the wetland loss occurred.

4. In selecting compensation sites, an applicant must pursue siting in areas conducive to wetland creation, enhancement, or restoration based on recommendations of a wetland biologist and approved by the City.

1. The Director may encourage, facilitate, and approve cooperative projects wherein a single applicant or other organization with demonstrated capability may undertake a compensation project with funding and/or support from other applicants under the following circumstances:

2. An applicant proposing a cooperative compensation project must:

1. Identification of Project Team. A compensation project manager must be named and the qualifications of each team member involved in preparing the mitigation plan and implementing and supervising the project must be provided, including educational background and areas of expertise, training and experience with comparable projects.

2. Baseline Information. A written assessment and accompanying maps of the environmental conditions of the impacted regulated wetland and the mitigation site if different.

3. Environmental Goals and Objectives. A written study must be provided identifying goals and objectives of the mitigation plan. The goals and objectives must be related to the functions and values of the original wetland or, if out-of-kind, the type of wetland to be emulated and an analysis of the likelihood of success of the created or restored wetland.

4. Performance Standards. Specific criteria, including ecological, geological, or hydrological criteria, must be provided for evaluating whether or not the goals and objectives of the project will be met and whether or not remedial action or contingency measures should be initiated. Performance standards must be meaningful, measurable, and achievable by methods and in the time frame identified in the mitigation monitoring plan.

5. Detailed Landscape Construction Plans. Landscape construction plans must:

6. Monitoring Program.

7. Maintenance Program. All wetlands located adjacent to a proposed development must be maintained by the property owner in perpetuity.

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

1. Demonstrate sufficient scientific expertise, supervisory capability, and financial resources to successfully carry out the mitigation project;

2. Demonstrate the capability of monitoring the site and make corrections during the monitoring period if the project fails to meet projected goals; and

3. Protect and manage or provide for the protection and management of the compensation area to avoid further development or degradation and to provide for long-term persistence of the compensation area.

1. Evidence showing the pond was artificially created include design plans, as-builts, or historically mapped upland soils and/or aerial photographs.

2. Landscape amenities that are immediately upstream of a fish-bearing stream and have a free and open connection to that stream with no barriers to fish passage are subject to FWHCA rules.

3. The borders of an artificial pond may be subject to FWHCA rules if it has been unmaintained for long enough to contain wetland vegetation and hydric soils along the edges.

1. Riparian areas and stream buffers as determined by widths in IMC 18.802.330; or

2. Biodiversity corridors as determined by WDFW PHS maps.

1. No development may be allowed within a FWHCA or FWHCA buffer with which State or Federally endangered, threatened, or sensitive species have a primary association unless a management plan consistent with applicable State or Federal agency regulations or guidance is provided. WDFW priority species and habitats must be protected through management recommendations as indicated by WDFW PHS management recommendations or through consultation with the regional habitat biologist. Appropriate management measures must be included in a critical areas study prepared by a qualified professional for review by the City. The City may require a consultation with the respective agency prior to approval.

2. Development proposals on sites containing streams must meet the requirements of both Article III of this chapter, Wetlands, and the standards in this section. When development activity is on a site containing both a FWHCA and an applicable stream according to other sections of this chapter, the buffer is the wider of the delineations.

3. The applicant must notify affected communities and native tribes of stream or stream alteration plans prior to any alteration of a stream, and submit evidence of the notification to the Federal Insurance and Mitigation Administration (FIMA).

4. Any approval of alterations or impacts to a FWHCA must be supported by the best available science.

5. There may not be introduction of any nonindigenous vegetation or wildlife to the King County lowlands into any FWHCA or associated buffers unless authorized by the State of Washington or a Federal license or permit.

6. Contiguous Corridors. FWHCA mitigation sites must be located to preserve or achieve contiguous wildlife habitat corridors in accordance with a mitigation plan that is part of an approved critical areas study to minimize the isolating effects of development on habitat areas, so long as mitigation of aquatic habitat is located within the same aquatic ecosystem as the area disturbed.

7. Mitigation for alterations to FWHCA must achieve no net loss of functions, values, and acreage and must include mitigation for adverse impacts upstream (or upslope) or downstream (or downslope) of the development site. Best available science must be used to determine the existing and projected functions and values being affected. Mitigation must address each function affected by the alteration to achieve functional equivalency or improvement on a per function basis.

8. All proposed activities within or adjacent to FWHCAs containing wetlands or other critical areas must conform to the development standards and buffer requirements set forth in this chapter. If two or more critical areas are present at the same location, the provisions of this chapter which provide the greater protection to the habitat apply.

1. Minimum Requirements and Types of Mitigation.

2. Location.

3. Standards for Restoration, Enhancement or Replacement.

4. Monitoring Program. Stream and stream buffer monitoring is required in accordance with IMC 18.802.460.

5. Maintenance Program. All streams and stream buffers adjacent to proposed development must be maintained in perpetuity based on direction from the Director with input from City staff. (Ord. 3019 § 2 (Exh. B), 2023).

1. Type S Streams. “Type S streams” means those streams identified as “shorelines of the State” under the City Shoreline Master Program, pursuant to Chapter 90.58 RCW.

2. Type F Streams. “Type F streams” are those streams that are not Type S streams and are either perennial or intermittent and have fish use or the potential to support fish use as described in WAC 222-16-031.

3. Type Np Streams. “Type Np streams” are those streams that are not Type S or Type F. They have flow year-round during normal rainfall and may have spatially intermittent dry reaches downstream of the uppermost point of perennial flow. Normal rainfall is determined by the Public Works Director. Type Np streams are not used by fish and do not have the potential to be used by fish. If the uppermost point of perennial flow cannot be identified with simple, nontechnical observations, then the point of perennial flow should be determined using the best professional judgement of a qualified professional.

4. Type Ns Streams. “Type Ns streams” are those streams that are not Type S, Type F, or Type Np. They are intermittent, are not used by fish and do not have the potential to provide salmonid fish habitat. Type Ns streams must have a free and open surface connection to a Type S, Type F, or Type Np stream.

1. Streams where naturally reoccurring use by fish has been documented or verified by a government agency;

2. Stream segments having a defined channel of:

1. Stream buffer widths required by this section assume that the stream buffer is well vegetated with native species appropriate to the site and are considered to be the minimum required to sufficiently achieve riparian and aquatic ecosystem protection and functions. If the stream buffer does not consist of vegetation adequate to provide stream protection and stream buffer functions, the director may require that the stream buffer be planted to achieve such protection and functions.

1. Where the horizontal length of the slope, including small benches and terraces, is within the buffer for that stream class, the stream buffer must be the greater of:

2. Where the horizontal length of the slope extends beyond the minimum stream buffer for that stream class, the stream buffer must extend to a point 25 feet beyond the minimum stream buffer for that stream class.

3. Stream buffer reductions shall not be allowed.

1. Critical drainage areas;

2. Location of hazardous materials;

3. FWHCAs and habitat connections based on an approved habitat management plan as defined by the WDFW;

4. Landslide or erosion hazard areas;

5. Groundwater recharge and discharge;

6. The location of trail or utility corridors; and

7. Water quality listed waters as defined by the Department of Ecology. (Ord. 3019 § 2 (Exh. B), 2023).

1. All road and utility crossings must use bridges or other construction techniques which do not disturb the stream bed or bank. Appropriate methods must demonstrate compliance with WDFW Water Crossing Design Guidelines and will accommodate 100-year flood flows as established by the City. This must be accomplished through bridge crossing design and/or appropriate flood control facilities constructed as part of the project design. Any structure spanning a stream must be designed so the supporting foundation is outside the ordinary high water mark;

2. All crossings must be constructed during summer low flow and be timed to avoid stream disturbance during periods when use is critical to salmonids;

3. Crossings may not occur over salmonid spawning areas unless no other possible crossing site exists on the subject property;

4. Crossings may not diminish the flood carrying capacity of the stream;

5. Underground utility crossings must be located at a preferred depth of four feet below the maximum depth of scour for the base flood predicted by a Washington State licensed civil engineer and be constructed in a manner approved by the Washington State Department of Fish and Wildlife; and

6. Crossings must be minimized and serve multiple purposes and properties whenever possible;

7. Crossing requirements do not apply to ditches, only to streams and waters of the State.

1. Type S streams may not be relocated, except for approved restoration projects.

2. Type F streams may not be relocated except for approved restoration projects and public road projects which have been authorized by the exemption process set out in IMC 18.802.030.

3. Type Np and Type Ns streams may be relocated under a mitigation plan for the purpose of enhancement of in-stream resources. Appropriate floodplain protection measures must be used. The relocation must occur on site; provided, that upon demonstration that on-site relocation is impracticable, the City may consider off-site relocation if the location is in the same drainage sub-basin and the applicant obtains all necessary easements and waivers from affected property owners.

4. Prior to any stream relocation, an applicant must demonstrate that the proposed project meets the following criteria, based on information provided by a licensed engineer and a biologist. All work performed must also be carried out under the supervision of a licensed engineer and a biologist. The criteria include the following:

1. The values and functions of the watercourse are improved including reducing stream flow during storm and flood events, and providing fish and wildlife habitat.

2. No adverse impact to fish are expected to occur.

3. Water quality is equal or better than existing condition.

4. Hydraulic capacity is maintained within the new channel.

5. The watercourse design complies with the Washington Department of Fish and Wildlife Water Crossing Design Guidelines Manual 2013 as it now reads and as hereafter updated or amended.

1. Bioengineered stabilization will be the preferred method unless demonstrated by a qualified professional that this method of stabilization will not function in the location or there is a significant possibility that such a structure will be damaged within three years because of streambank erosion in the absence of such hard armoring measures.

2. New, expanded, or replaced bank stabilization or flood control structures may be allowed when:

3. New stream bank stabilization structures must incorporate features that minimize adverse effects on riparian habitat, salmon spawning and migration, and water quality. Such features must include native vegetation, large wood, rocks, and other techniques that have been shown mitigate the effects of bank armoring on stream ecology. Approaches consistent with Washington Department of Fish and Wildlife bank stabilization guidelines will be approved.

4. The following information is required for new streambank stabilization:

1. Surface water discharges to streams from stormwater facilities or other surface water management structures having no feasible alternative on-site locations may be allowed so long as the discharge complies with the provisions of the City’s currently adopted Stormwater Design Manual.

2. Flood conveyance compensatory storage may be allowed where there is no other feasible alternative, where appropriate restoration is included, and where wetland hydrology will not be significantly affected.

3. Stormwater low-impact development and vegetative flow paths from level spreaders may be allowed in the outer 25 percent of the stream buffers only if the applicant demonstrates that no feasible alternative on-site location exists and the project would not adversely affect the stream flow or the function or values of the stream buffer or stream, and it must meet the clean water standards of Chapter 90.48 RCW and Chapters 173-200 and 173-201A WAC as amended. Water quality monitoring may be required as well as the following:

1. No practical alternative location is available;

2. The utility corridor meets the criteria set forth in the applicable City ordinance including, but not limited to, requirements for installation, replacement of vegetation, and maintenance;

3. Impacts to the buffer area are minimized and restoration is implemented to the greatest extent feasible; and

4. The requirements for sewer utility corridors in IMC 18.802.230(A) must also apply to stream buffers.

1. Enhancement of streams, not associated with any other development proposal, may be allowed when the City, or any State agency with jurisdiction, determines that such enhancement benefits stream functions. Such enhancement must be performed under a plan for the design, implementation, maintenance, and monitoring of the project prepared by a professional engineer licensed in Washington State and a biologist, and must be carried out under the direct supervision of a biologist.

2. Stream restoration projects for fish habitat enhancement by a public agency unassociated with mitigation of a specific development proposal may be allowed. Such projects are limited to placement of log controls, spawning gravel, and other specific salmonid habitat improvements to be performed under direct supervision of a biologist, within the approved WDFW window, if applicable.

3. Removal of exotic or invasive plants within streams and stream buffers is allowed. A City-approved mitigation plan is required before removal of vegetation commences.

1. The proposed activity may not cause contaminants to enter a wellhead protection area and the proposed activity will not adversely affect the recharging of the aquifer.

2. Remediation of existing subsurface contamination must be completed and the site issued a “No Further Action Order” by Ecology (or equivalent) before a certificate of occupancy is issued.

3. The activity may not adversely impact the quality, direction, flow, or volume of groundwater or changes in the infiltration/recharge rate.

4. Implement best management practices (BMPs) according to groundwater quality standards for CARA per Chapter 13.29 IMC, Groundwater Quality Protection Standards, and groundwater quantity standards and requirements for infiltration in Chapter 13.28 IMC, Stormwater Management Policy.

5. Temporary construction dewatering impacts on the surrounding environment must be minimized; the following potential impacts must be evaluated and analysis provided to the City when proposing dewatering:

6. Temporary construction dewatering of the aquifer as part of a construction project will not be allowed in CARA Class 1 or 2, unless a project specific temporary construction dewatering feasibility study has been submitted and approved by the City prior to issuance of the land use decision or construction permit for the project that requires dewatering.

7. Exemptions from the requirement to submit a temporary construction dewatering feasibility study for developments in CARA Class 1 or 2 will be considered upon submittal of a written request documenting that the development site meets at least one of the following criteria:

1. Prevent the release of such substances to the ground, groundwaters, or surface waters;

2. Use storage containment area materials that are, through the construction or lining, compatible with the stored substance to protect against corrosion or leakage; or otherwise, use storage containment designed in a manner to prevent the release or threatened release of any substance, including within secondary containment as defined in Chapter 18.102 IMC;

3. Provide for release detection, as defined in Chapter 18.102 IMC, as applicable, for uses such as fuel tanks and similar hazardous material storage;

4. Per IMC 13.29.020 requirements, provide hazardous materials management plans (HMMP) or hazardous materials inventory (HMI) written spill response and spill notification procedures to the Public Works Department; submit a hazardous material construction inventory (HMCI) to the Public Works Department for new construction within the CARA; and comply with Fire Code requirements that apply to hazardous materials; and

5. Comply with Chapters 173-303 and 173-360 WAC, Chapters 13.28 and 13.29 IMC, and Chapter 70.105 RCW.

1. Identify and characterize any critical area as a part of the larger development proposal site;

2. Assess any hazards to the proposed development;

3. Assess impacts of the development proposal on any critical areas located on or adjacent to the development proposal site;

4. Assess the impacts of any alteration proposed for a critical area; and

5. Propose mitigation, maintenance and monitoring plans and bonding measures.

1. Vicinity Information.

2. Site Plan.

3. Project Description.

4. Additional Information. The Director may require the following additional information:

5. Subsurface data used to characterize subsurface conditions data must be included.

1. City staff will post critical areas study on the City’s website for all projects requiring Level 2 land use permit or higher, consistent with all notice requirements of IMC 18.204.030.

2. The Community Planning and Development Department will select one, or more, qualified professionals to conduct a peer review of selected critical areas studies. The City may consider adding other consultants that are not on the list of qualified specialists based on submitted qualifications at the request of the applicant.

3. If it is determined that the proposed regulated activity will occur within a critical area or critical area buffer, an approval must be granted through the appropriate land use permitting process prior to any development activity occurring on the site.

4. Critical area studies may be reviewed independent of a development permit pursuant to the technical document review procedures of IMC 18.204.060.

1. The applicant demonstrates:

2. A critical areas study was prepared and provided previously for a development which currently requires a single-family residential building permit, and the previous study adequately identified the impacts associated with the current development proposal; or

3. The proposed development is utilizing nonconforming provisions of IMC 18.214.070(C)(4)(b)(1) through (C)(4)(b)(4). (Ord. 3070 § 1 (Exh. A), 2024; Ord. 3019 § 2 (Exh. B), 2023).

1. Include a map illustrating:

2. Complete a subsurface investigation program adequate to describe the geologic units, the failure surface(s), and groundwater elevations with a period of monitoring long enough to describe the seasonal high groundwater elevation. Create geologic cross sections using all available subsurface information. The geologic sections must inform the slope stability models generated for engineering analysis of slope factor of safety.

3. Include an analytical assessment using currently available commercial slope stability software of the landslide stability. If the site is contained within a larger mapped landslide, the assessment must consider reactivation of all or a portion of the landslide.

4. Conduct a surface reconnaissance of the site and adjacent area using LiDAR (light detection and ranging) derived elevation data. Data for the entirety of the City of Issaquah is publicly available to supplement traditional mapping techniques.

1. Description of shear test procedures (ASTM or other), shear strength plots, sample identification;

2. Explanation of choice of seismic coefficient and of design strong-motion record used in slope stability analysis including any amplification estimates;

3. Slope stability analyses of critical cross sections of natural, at time of construction, and final slope conditions and resultant factors of safety;

4. Conclusions regarding the stability of slopes with respect to earthquake induced landslides and their likely impact on site development; and

5. Discussion of proposed mitigation measures, if necessary;

6. Surface reconnaissance of the site and adjacent area using LiDAR (light detection and ranging) derived elevation data. Data for the entirety of the City of Issaquah is publicly available to supplement traditional mapping techniques;

7. Conduct a subsurface exploration suitable to the site and development proposal to assess slope stability and geohydrological conditions;

8. A map or site plan showing:

1. If methods other than standard penetration test (SPT; ASTM D1586, ASTM D6066) and cone penetration test (SPT; ASTM 3441) are used, a description of pertinent equipment and procedural details of field measurements of penetration resistance is required;

2. Boring logs showing raw N-values if SPTs are performed; CPT probe logs showing raw qc-values and plots of raw sleeve friction if CPTs are performed;

3. Explanation of the basis and methods used to convert raw SPT, CPT, and/or other nonstandard data to “corrected” and “standardized” values and tables or plots of the values used in analysis;

4. Explanation of the methods used to develop estimates of cyclic stress ratio and cyclic loading, and basis for evaluating uniform cyclic stress ration necessary to cause liquefaction;

5. Factors of safety against liquefaction at various depths and soil units; and

6. Conclusions regarding potential for liquefaction and its likely impact on the project and proposed mitigation measures to reduce potential damage to an acceptable level of risk.

1. Surface reconnaissance of the site and adjacent area using LiDAR (light detection and ranging) derived elevation data. Data for the entirety of the City of Issaquah is publicly available to supplement traditional mapping techniques.

2. Conduct a subsurface exploration suitable to the site and development proposal to assess slope stability and geohydrological conditions.

3. A map or site plan showing:

1. Historical mining data, including available copies of original mine records for mine workings in coal seams.

2. A map showing property boundaries, mine feature boundaries, and any potential hazards identified on or within 300 feet of the property.

3. If hazards were identified, include a description of the detailed site investigation completed to support engineering design for remediation.

4. The site-specific evaluation of potential collapse or subsidence must include a detailed review of available copies of original mine records for mine workings in coal seams that could potentially influence the site by collapse or trough subsidence. The locations, depths, and thicknesses of such seams and workings must be documented. Coal mine workings that could potentially influence the site are determined by projecting the downdip limit angle from the lowest limit of the documented workings to the ground surface. Mine workings are considered to potentially influence the property if the property lies within the line at which the limit angle intersects the ground surface.

5. Subsurface Investigations. Subsurface conditions may be evaluated by drilling. Although drilling is not compulsory, it is the most acceptable method for providing information that is acceptable for reducing the remaining mine height value used in subsidence calculations. Indirect means of subsurface evaluation, including geophysics, geologic projection, and evaluation of mining records, may be used to supplement drilling results, but may not be used as the sole source for evaluating subsurface conditions. Rotary drilling is an acceptable method of drilling, but only if it is used in combination with downhole geophysical logging, including caliper logs. Core drilling may be used immediately above and through the predicted coal seam locations to facilitate interpretation of the condition of the mine workings. Rotary drillholes must be logged continuously from 100 feet above to 20 feet below mine workings, including lithology at five-foot intervals, drill fluid circulation, penetration rate, and free fall of the drill string. Greater confidence will be placed in core drilling logs than rotary drilling logs. As a guideline, it is recommended that a minimum of one drillhole penetrating each coal seam that could potentially cause trough subsidence at the site should be drilled for each 200-foot length of the property boundary. If a drillhole encounters solid or broken coal in an area that available mine maps indicate it has been mined out, it may be assumed that the true thickness of coal represents the thickness of intact or crushed pillars and corresponds to the remaining mine height for calculating potential trough subsidence affects at surface. If the drillhole encounters voids at or above the location of the coal seam, the cumulative length of the voids can be used to calculate the true cumulative thickness of the voids, which may be taken to correspond to the remaining mine height. These assumptions can be modified based on additional drilling. Direct evidence of the condition of panels in the same seam with similar dimensions, similar extraction ratios, and at a similar or shallower depth must be accepted as evidence of the condition of mine workings at any point. Surface geophysics, or other indirect means, may be used to assist in projecting information between and beyond drillholes, but may not be accepted as the sole method for evaluating the condition of underground mine workings and calculating remaining mine height. Assumptions concerning the extent of collapse of mine workings based on recorded extraction ratios must be conservative because of possible inaccuracies of mine records, the likely presence of remnant pillars and the lack of data to accurately locate them.

6. Calculation of trough subsidence magnitudes, tilts, and strains and assumptions used in the analysis must be described in the study. The recommended method for calculating potential trough subsidence magnitudes, strains, and tilts is the empirical function method of the British National Coal Board, as presented in their Subsidence Engineers’ Handbook (National Coal Board, 1975, Subsidence Engineers’ Handbook), adjusted to reflect the effects of inclined seams and a downdip limit angle of 45 degrees. Calculations must be based on a conservative evaluation of site conditions developed from the review of available records, site investigation or other acceptable means, such as previous documentation by subsurface exploration of the condition of the coal seam(s) in the immediate vicinity of the site and at an equivalent depth below the ground surface. If direct subsurface investigation indicates that the mine workings are fully collapsed, an estimate of potential surface settlements due to consolidation of rubble and loose material must be made for sites directly underlain by coal mine workings. The subsidence analysis evaluates the cumulative effect of all seams that could induce trough subsidence at the site. Alternative methods of calculating potential subsidence magnitudes, strains, and tilts may be used provided they incorporate similar assumptions to those specified in the preceding subsections. If alternative design parameters and assumptions are proposed, detailed justification must be provided to the City.

7. Documentation of Trough Subsidence Evaluation. The results of the detailed site evaluation must be documented in the study. Site plans must be prepared showing the proposed development and calculated magnitudes of potential subsidence, strains, and tilts at the property boundaries and at the locations of any proposed structures. In addition, a map showing contours of potential subsidence magnitudes, strains, and tilts throughout the property must be submitted for use in design of roads and utilities. Appropriate recommendations must be provided for structural and civil design requirements.

8. Potential Sinkholes. Demonstrate by direct subsurface investigation that coal mine workings either do not exist, or that the workings have fully collapsed so that there is no remaining potential for sinkhole development; or show that the hazards associated with any voids that are identified are fully mitigated by backfilling, grouting, or other approved means such that the potential for sinkhole development is eliminated. Alternatively, demonstrate that workings are too deep to result in sinkhole formation at the ground surface.

1. The thickness and limits of peat deposits on a site should be explored and described using report figures, laboratory testing and exploration logs.

2. The report should discuss how the development proposal plans to avoid peat deposits or, if avoidance is not feasible, evaluate the impacts of peat removal and describe mitigation methods proposed to achieve environmental protection of the peat deposit and mitigate settlement risk to the project and surrounding properties.

1. A wetland study, prepared either prior to or with a development application, where a site inspection or other available information indicates the potential of a wetland on any portion of the subject property or within 300 feet of the subject property.

2. A field identification or delineation of the wetland edge conducted by a qualified wetland professional based on the procedures provided in the currently approved Federal manual and applicable regional supplements and WAC 173-22-035.

3. Wetland delineations and wetland ratings based on the entire extent of the wetland, irrespective of property lines, ownership patterns, or other factors, which is approved by the Director prior to approval of development permits.

4. The final approved wetland delineation and required wetland buffer locations must be surveyed by a professional surveyor to sub-meter accuracy of the wetland edge and required wetland buffer. This information must be shown on the permit application. The survey of the wetland delineation must be tied to a known monument.

5. For parcels containing wetlands, the study must include the location and description of the vegetative cover, including dominant species of the regulated wetland and adjacent area.

1. The project area of the proposed activity;

2. All FWHCAs and recommended buffers within 300 feet of the project area;

3. All shoreline areas, floodplains, other critical areas, and related buffers within 300 feet of the project area; and

4. A discussion of the efforts to avoid and minimize potential effects to these resources and the implementation of mitigation/enhancement measures as required;

5. Habitat Assessment. A habitat assessment is an investigation of the project area to evaluate the potential presence or absence of designated critical fish or wildlife species or habitat. A critical areas study for a FWHCA must contain an assessment of habitats, including the following site- and project-related information at a minimum:

1. A long-term groundwater monitoring plan is required for any land use in the critical aquifer recharge areas that poses a high risk of contaminating groundwater, as determined by the Director. For example, land uses including fueling or the storage of large volumes of chemicals are considered high risk. The groundwater monitoring plan must comply with the contents and elements required under RCW 90.44.410.

2. A Phase 1 environmental site assessments (ESA) is required when any development or redevelopment project disturbs 2,000 square feet or more of soil in the critical aquifer recharge area. The Phase 1 ESA must be submitted with the critical areas study elements described in IMC 18.802.400.

3. A hydrogeologic critical areas assessment may be required by the Director for projects that may pose significant potential risk for groundwater contamination in Class 1 and 2 CARA areas and must include a determination of the proposed project’s potential impacts to groundwater and surface water. This assessment must include evaluation of the project’s potential impact to surface water, groundwater, and wetlands regulated under this Code. The evaluation should also include a predictive evaluation of:

4. Should a private party wish to request a change in the CARA classification of one or more parcels, a hydrogeologic critical areas assessment is required. This request shall require the applicant to submit an application for code amendment to amend the CARA map. The assessment must include sufficient geologic and/or groundwater flow information to justify a change in CARA classification. If the WHPA time of travel component of Table 18.802.370(A) is challenged, information must be submitted in a compatible format that can be incorporated into the City’s existing groundwater flow model. If the recharge potential component of Table 18.802.370(A) is challenged, information must include sufficient geologic characterization across the entire site. Requests to change the CARA classification will be evaluated by the City at the expense of the private party. The City’s evaluation may entail further model runs or hydrogeologic analysis. If the challenge is successful, the hydrogeologic critical areas assessment will be incorporated into the City’s WHPA model and/or surface geologic mapping and an updated CARA map adopted by City Council as part of the code amendment process.

5. Temporary construction dewatering feasibility studies that are required for CARA Class 1 and 2 critical areas must contain site-specific hydrogeological and engineering analysis developed by a qualified professional and will be subject to peer review. Exemptions from providing temporary construction dewatering feasibility studies are described in IMC 18.802.390(B). At a minimum, the study must contain:

1. All landslide and steep slope hazard areas;

2. Mine, flood, and seismic hazard areas;

3. Fish and wildlife habitat conservation areas (FWHCAs);

4. Wetlands one acre or greater in size; and

5. Streams.

1. Include an irrevocable offer to dedicate or convey the critical area easement to the City or other public or nonprofit entity approved by the City Attorney; or

2. Prohibit in perpetuity the development, alteration, or disturbance of vegetation within the critical area easement except for purposes of habitat enhancement as part of an enhancement project that has received prior written approval from the City, and any other agency with jurisdiction over such activity.

1. The purpose of the building setback area is to protect the critical area and its buffers from impacts from construction, shading, and indirect activities from adjacent developed property.

2. The use of hazardous or toxic substances and pesticides is prohibited in building setback areas for FWHCAs and wetlands.

3. Minor structural intrusions listed in IMC 18.404.030(J) may be allowed into the building setback area, if consistent with Chapter 18.600 IMC, Urban Design and Site Planning.

4. The building setback area must be identified on all land use permits and building permit site plans containing or adjacent to critical areas. (Ord. 3070 § 1 (Exh. A), 2024; Ord. 3019 § 2 (Exh. B), 2023).

1. For buffers, monitoring is required for a minimum of five years.

2. For direct aquatic resource impacts that require State and/or Federal permitting, monitoring is required for a minimum of 10 years.

3. Where monitoring reveals a significant deviation from predicted outcomes or a failure of mitigation measures, the permit holder is responsible for appropriate corrective action as specified by the Director which, when approved, is subject to additional monitoring.

1. There is no other reasonable economic use of the property that has less impact on the critical area;

2. The proposed impact to the critical area is the minimum necessary to allow for reasonable economic use of the property;

3. The inability of the applicant to derive reasonable economic use of the property is not the result of actions by the applicant or a predecessor in interest after the effective date of this regulation;

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

5. The proposal will result in no net loss of critical area functions and values consistent with the best available science;

6. The proposal is consistent with other applicable regulations and standards. (Ord. 3019 § 2 (Exh. B), 2023).

1. Bond amounts must cover the cost of design, installation, monitoring, and maintenance.

2. The bond must be 150 percent of the costs of the mitigation, maintenance, and monitoring cost.

3. The maintenance period must be five years.

4. If additional work is required after the five-year maintenance period is over, the bonding requirement may be extended per the Director. Public projects are exempt from submitting a separate bond in addition to their existing bond.

1. Between parties, through direct sale of development rights from a qualified sending site property owner to a qualified receiving site property owner; and

2. Between the City and a sending or receiving site property owner where the City may act as a TDR bank for development rights by purchasing TDRs from qualified sending sites and/or by selling them to an applicant for use on a qualified receiving site; and

3. Between King County’s TDR bank and a City receiving site, as authorized through an interlocal TDR agreement. (Ord. 3019 § 3 (Exh. C), 2023).

1. Inside City Limits. Sending sites in the City may be privately or publicly owned and must meet one or more of the following criteria:

2. Outside City Limits. Through an interlocal agreement with King County, the City will establish criteria for privately owned TDR sending sites outside the City limits, consistent with the provisions of an interlocal TDR agreement.

1. The parcel is within three-quarters of a mile from the Issaquah Transit Center; is south of I-90; and is zoned Mixed-Use Residential, Mixed-Use – Central Issaquah, Urban Core, Urban Village – Rowley, or Village Residential; or

2. The parcel is within one-quarter mile of a bus stop served by public transit; is zoned Intensive Commercial, Professional Office, Intensive Commercial – Central Issaquah, Mixed-Use, Mixed-Use – Central Issaquah, Urban Core, Village Residential, or Mixed-Use Residential; is located within the area designated Urban Village – Rowley; and the site’s primary access and street frontage are located on “major streets” defined as: Gilman Boulevard east of SR 900, Newport Way, SR 900, NW Sammamish Road, NW Maple Street, East Lake Sammamish Parkway (ELSP), SE 56th Street to 1,200 feet east of East Lake Sammamish Parkway, Issaquah-Fall City Road, or Issaquah-Pine Lake Road SE; or

3. The parcel is a Multifamily zoned property located within the Central Issaquah subarea.

1. Facilitate the purchase and sale of development rights;

2. Purchase privately held TDR certificates; and

3. Acquire open space and park lands, as directed by the City Council.

1. The TDR bank may acquire development rights from any designated sending site as identified in the map at Figure 18.806.030(D), TDR sending and receiving sites map.

2. The TDR bank may collect funds or other donations from any designated TDR sending or receiving site, as identified in the map at Figure 18.806.030(D), TDR sending and receiving sites map.

3. The TDR bank may purchase and hold title to existing TDR certificates.

4. Development rights purchased by the TDR bank through the purchase of fee simple ownership of a sending site property, or through the purchase of only the development rights from a sending site property, may be retained by the bank indefinitely.

5. Transferred development rights must be certified by the City and may be purchased by an applicant for a land use development project within the City for immediate use; or an applicant may purchase TDRs to hold for future use without expiration; or TDRs may be sold or transferred to another party. (Ord. 3019 § 3 (Exh. C), 2023).

1. Managing the activities of the TDR bank;

2. Authorizing and monitoring the availability of TDR certificates;

3. Monitoring compliance with the interlocal TDR agreement executed with King County;

4. Administering development rights purchases, sales and issuance of letters of intent and certification;

5. Providing periodic summary reports of the TDR bank activity to the City Council; and

6. Setting the value of TDR bank-issued TDR certificates as outlined in IMC 18.806.060.

1. Issued a letter of intent;

2. Purchased and certified; and

3. Sold and extinguished.

1. Reimbursement of general fund expenditures for acquisition of property that is later designated as a TDR sending site;

2. Purchasing development rights or fee simple ownership rights from property identified in the map at Figure 18.806.030(D) for use as open space or park;

3. Purchasing existing privately held TDR certificates; or

4. Facilitating the implementation of this chapter using not more than five percent of the TDR bank funds, unless a higher amount is approved by the City Council; facilitating includes establishing and maintaining internet web pages, marketing the TDR program, legal expenses, procuring title reports and appraisals and reimbursing the costs incurred by City departments for administering the bank fund and executing development rights purchases and sales. (Ord. 3019 § 3 (Exh. C), 2023).

1. A certification that the development rights, if used, must be used in a receiving site identified on the City’s map or used per interlocal agreement with King County;

2. A minimum 10 percent down payment with purchase offer; and

3. The number of development rights to be purchased, location of the receiving site, proposed purchase price, and date of closing of the TDR sale, which may be not later than one year after the City accepts the purchase offer.

1. Eligibility. In order to sell or transfer development rights, the property owner must receive certification from either the City or King County consistent with the provisions of the City’s TDR interlocal agreement. Subsections (A)(2) through (A)(5) of this section establish the methodology for calculating the TDR base density. TDR base density is the basis for establishing the number of TDR certificates.

2. Calculation of TDRs Inside the City for Residential Sites With Critical Areas. For development proposals containing critical areas and associated critical area buffers that occupy at least 30 percent of a development site, the Director may determine allowable dwelling units for residential TDR base density using the formula below.

3. Calculation of TDRs Inside the City for Residential Sites Without Critical Areas. For residentially zoned properties, the TDR base density is calculated based on the maximum allowed dwelling units.

4. Calculation of TDRs Inside the City for Nonresidential Sites With or Without Critical Areas. For nonresidentially zoned properties, the TDR base density is calculated based on the maximum buildable square footage of the buildable area on the site divided by 1,200 square feet.

5. Calculation of TDRs Outside the City Limits for Sites With or Without Critical Areas. The maximum transferable number of development rights by a sending site outside of the City limits must be established through the King County certification process as required by the Issaquah/King County interlocal agreement. Each TDR unit certified by King County in this manner may be used by an Issaquah receiving site with the same process and requirements of an “inside City limits” sending site TDR unit.

6. TDR Certificate Letter of Intent. When located in the City, the Director prepares and issues a TDR certificate letter of intent for the sending site which documents the available development rights on that sending site. If any of these development rights achieve certification, the letter of intent must be reissued to reflect the new amount of remaining development rights.

7. TDR Certificate Letter of Intent Revision Request. The applicant may request, in writing, that the Director revise the TDR certificate within 90 days of the issuance of the TDR certification letter of intent if:

1. Certifying TDRs.

2. TDR Certificate Content. A TDR certificate is a recorded document, showing the number of development rights available from a qualified sending site to be used by a TDR receiving site, and must delineate the number of development rights including:

3. Preservation of Open Space or Dedication of Park Land Resulting From TDR Conversion. As part of the development rights transfer and prior to the issuance of the TDR certificate, the sending site property owner is required to document that the site, or portion of the site, is no longer developable and must be preserved to fulfill the intent of this chapter in one of the following ways, as determined by the Director:

4. Reissuing TDR Certificates. The Director administers the TDR program by reissuing or retiring certificates when some or all of a parcel’s development rights have been transferred. A TDR certificate must be reissued and recorded after the sale of TDRs to the receiving site owner and the recording of a conservation easement, covenant, or conveyance of the sending site property to the City as public open space or park land. The reissued TDR certificate must clearly state the number of remaining TDRs available for that sending site parcel. If no TDRs are available, that information must also be recorded.

1. Transferring All of the TDRs. All or a portion of the TDRs certified by the Director may be sold. If all of the TDRs are transferred, no further development must occur on the sending site and the entire parcel must remain in permanent open space or park land in perpetuity in accordance with the provisions of subsection (B)(3) of this section.

2. Transferring TDRs Over Time. TDRs from a sending site may be sold over time to more than one receiving site until all development rights are sold or the property owner chooses to develop the remainder of the property.

3. Calculating Any Remaining Density on the Sending Site. If only a portion of the TDR units from a sending site are sold and transferred, the number of dwelling units or, in the case of commercially zoned land, the buildable square footage permitted on the remainder property, must be determined in accordance with the conservation easement and provisions of IMC based on the percentage of critical areas on the site. (Ord. 3019 § 3 (Exh. C), 2023).

1. Applicability. Receiving sites may use the purchased TDRs to meet the provisions of an approved development agreement or to exceed the allowable development for new development or modification to existing development, in accordance with this chapter; provided, that all development and design standards required by the underlying zoning district must be met, unless the standards are adjusted through IMC 18.806.090, Receiving TDRs – Standards.

2. The City may, in its sole discretion, elect not to accept conveyance of the property if intended as open space, and require the property owner to retain ownership of the property and record a permanent conservation easement thereon in accordance with IMC 18.806.070(B)(3), Preservation of Open Space or Dedication of Park Land Resulting From TDR Conversion.

3. Procedures.

1. TDR development rights where both the proposed sending and receiving sites are in the City shall be transferred using the following process;

2. Approval of the sending site application shall be as described in IMC 18.806.070. After signing and notarizing the conservation easement and receiving the TDR certificate from the City, the sending site owner may market the TDR sending site development rights to potential purchasers. The TDR certificate shall be in the name of the property owner and separate from the land title. If a TDR sending site changes ownership, the TDR certificate may be transferred to the new owner if requested in writing to the City and if documents evidencing the transfer of ownership are also provided to the City;

3. In applying for a receiving site approval per this section that shows how receiving site standards of IMC 18.806.090 are met, the applicant shall provide the City a TDR certificate issued in the name of the applicant, or a TDR certificate issued in the name of another person or persons and a copy of a signed option to purchase those TDR sending site development rights;

4. As part of either a land use application or building permit application that includes the use of TDR development rights, the receiving site applicant shall deliver the TDR certificate issued in the applicant’s name for the number of TDR development rights being used and the TDR extinguishment document to the City. The development rights must be purchased and a TDR quit claim deed and extinguishment document must be recorded on the sending site and receiving parcels conveying transferable development rights as defined in IMC 18.806.070 through 18.806.090;

5. Development rights from a sending site shall be considered transferred to a receiving site when a final decision is made on the TDR receiving area development proposal, appeal rights have been completed pursuant to IMC 18.806.100, the sending site is permanently protected by a completed and recorded land dedication or conservation easement, notification has been provided to the King County Assessor’s Office, and a TDR extinguishment document has been provided to the City.

1. Plat Application. TDR receiving sites may be subdivided in accordance with the requirements of Chapters 18.300 through 18.390 IMC, Division of Land. The preliminary plat or short plat application must include a pro rata portion of the development rights transferred to the original parcel to each parcel created by the subdivision. At time of application, the applicant must provide a signed option letter indicating the buyer, seller, sending and receiving site legal descriptions and the number of development rights to be acquired. The pro rata assignment of transferred development rights must only be in whole units. Individual TDRs may not be divided and the individual uses of a TDR may not be assigned to a different parcel.

2. Plat Modifications. The Hearing Examiner’s decision on a preliminary plat and the Director’s decision on a short plat may modify the assignment of TDRs proposed by the applicant when such modification is necessary to comply with the provisions of subsection B of this section, Transfer of Development Rights (TDR) Program – Transfer Process, or the objectives of IMC 18.300.010, Purpose.

3. Plat Approval. Upon plat approval, the new assignment of the TDRs must be shown on the face of the short plat or final plat approved by the City and must be recorded with King County. Final plat approval must be contingent on the applicant providing TDR certificates with the equivalent number of additional development rights necessary within the plat as approved by the City. (Ord. 3019 § 3 (Exh. C), 2023).

1. Density.

2. Height.

3. Impervious surface.

1. “Director” is the Planning Director or their designee.

2. “Person in charge” is the person or persons in possession of a landmark including, but not limited to, mortgagee or vendee in possession, an assignee of rents, a receiver, executor, trustee, lessee, tenant, agent, or any other person directly or indirectly in control of the landmark, as designated by the owner/agent authorization.

1. Cemeteries, birthplaces, or graves of historical figures, properties owned by religious institutions or used for religious purposes, structures that have been moved from their original locations, reconstructed historic buildings, properties primarily commemorative in nature, and properties that have achieved significance within the past 40 years may not be considered eligible for designation except under certain circumstances.

1. The building official will seek and take into consideration the comments of the Historic Preservation Officer regarding mitigation of any adverse impacts.

1. Site and building design on forested hillside sites;

2. Street and access design on hillside sites;

3. Design and placement of retaining walls;

4. Preserve wildlife migration access for a healthy and connected landscape;

5. Management of grading to avoid excessive cuts and fills; and

6. Preservation of hillsides while allowing appropriate development.

1. To preserve trees and forested areas;

2. To maintain natural site characteristics and to minimize view impacts from development;

3. To allow an appropriate level of development, generally avoiding intensive development of forested hillsides, while allowing sloped sites in Central Issaquah to develop with more intensity;

4. To minimize forest fragmentation and retain existing stands of trees;

5. To ensure retaining walls do not dominate the streetscape;

6. To avoid heavy regrading that would require many truck trips during construction; and

7. To ensure a connected network of paths, trails, and safe street crossings. (Ord. 3019 § 5 (Exh. E), 2023).

1. Where:

2. Contour intervals and length of contour lines must be calculated using a topographic map having a scale of not less than one inch equals 200 feet and a contour interval of not more than five feet.

3. See Figure 18.810.030(C) for an example.

4. In the case of a flat area on a site with repeated contours for the same elevation, measure one contour line and include it once in the calculation. The Director must also review and approve the calculation. For example, this would apply to a site with a small hill in the middle of a slope on a site.

1. The development otherwise must comply with this chapter per IMC 18.810.020, Applicability;

2. The project site is either located in Central Issaquah or contains and maintains over 51 percent tree canopy coverage; and

3. Deviations are only allowed from wall height, terracing, or grading standards of this chapter.

1. A preapplication meeting is required pursuant to IMC 18.202.050, Preapplication staff meeting.

2. Submittal Requirements. The applicant must submit all information required by the most current submittal requirements published by the permit center in advance of the meeting.

1. The proposal better achieves the overall priorities of this chapter, as outlined in IMC 18.810.010(B), Priorities for Protection;

2. The proposal complies with Chapter 18.812 IMC, Tree Preservation; and