20D.140.10 Sensitive Areas

(1) The City finds that Redmond contains certain areas that can be identified and characterized as environmentally sensitive or critical. Such areas within the City include wetlands, streams, wildlife habitat, geologic hazards, aquifer recharge areas, and flood hazards, and their associated buffers.

(2) The City finds that past growth patterns have in some cases resulted in natural disasters which threaten public health and safety, and that by preventing development on certain sensitive areas the City can better maintain public health, safety and welfare by avoiding natural disasters such as slides and flooding that threaten life and property. In addition, by preserving features that provide for clean water, fisheries, and wildlife, the City can help maintain a positive ecological balance that provides for the immediate and long-term public welfare. This chapter is intended to preserve the City’s important environmental features while allowing development to occur if compatible with and in consideration of these sensitive areas.

(3) The classification and designation of these sensitive areas is intended to assure the conservation and protection of sensitive areas from loss or degradation, and to restrict land uses and development which are incompatible with environmentally sensitive areas. It is the intent of this chapter to designate and protect sensitive areas.

(4) The City finds that these essential sensitive areas perform a variety of valuable and beneficial biological and physical functions that benefit the City and its residents. Some types of sensitive areas may also pose a threat to human safety or to public and private property. The City further finds that the functions of sensitive areas include the following:

(a) Wetlands. Wetlands help to maintain water quality; store and convey storm water and floodwater; recharge ground water; provide important fish and wildlife habitat; and serve as areas for recreation, education and scientific study and aesthetic appreciation. The City’s overall goal shall be to achieve no net loss of wetlands. This goal shall be implemented through retention of the function, value and acreage of wetlands within the City. Wetland buffers serve to moderate runoff volume and flow rates; reduce sediment, chemical nutrient and toxic pollutants; provide shading to maintain desirable water temperatures; provide habitat for wildlife; protect wetland resources from harmful intrusion; and generally preserve the ecological integrity of the wetland area.

The primary purpose of the wetland regulations is to avoid wetland impacts and achieve a goal of no net loss of wetland function, value and acreage; and where possible enhance and restore wetlands.

(b) Streams. Streams and their associated buffers provide important fish and wildlife habitat and corridors; help to maintain water quality; store and convey storm water and floodwater; recharge ground water; and serve as areas for recreation, education and scientific study and aesthetic appreciation.

The primary purpose of the stream regulations is to avoid impacts to streams and associated riparian corridors; and where possible, provide for stream enhancement and rehabilitation.

(c) Wildlife Habitat. Wildlife habitat provides opportunities for food, cover, nesting, breeding and movement for fish and wildlife within the City; maintains and promotes diversity of species and habitat within the City; coordinates habitat protection with elements of the City’s open space system wherever possible; helps to maintain air and water quality; controls erosion; serves as areas for recreation, education and scientific study and aesthetic appreciation; and provides neighborhood separation and visual diversity within urban areas.

The primary purpose of wildlife habitat regulation is to avoid impacts to critical habitats and to restore and enhance degraded or lower-quality habitat.

(d) Geologic Hazard Areas. Geologic hazard areas include lands that are affected by natural processes that make them susceptible to landslides, seismic activity and severe erosion.

The primary purpose of geologic hazard area regulations is to avoid and minimize potential impacts to life and property from geologic hazards through appropriate levels of study and analysis, application of sound engineering principles, and regulation or limitation of land uses.

(e) Aquifer Recharge Areas. Aquifer recharge areas provide a source of potable water and contribute to stream discharge during periods of low flow. The City finds that certain portions of its planning area are susceptible to contamination of drinking water and watercourse supplies through rapid infiltration of pollutants through the soil to ground water aquifers.

The primary purpose of aquifer recharge area regulations is to protect critical aquifer recharge areas by avoiding land use activities that pose potential contamination; and to minimize impacts to recharge areas through the application of strict performance standards.

Wellhead Protection Zones 1, 2, and 3 are designated as critical aquifer recharge areas under the provisions of the Growth Management Act (Chapter 36.70A RCW) and are established based on proximity to and travel time of groundwater to the City’s public water source wells.

(f) Flood Hazard Areas. Floodplains help to store and convey storm water and flood water; recharge ground water; provide important areas for riparian habitat; and serve as areas for recreation, and education and scientific study. Development within floodplain areas can be hazardous to those inhabiting such development, and to those living upstream and downstream. Floods also cause substantial damage to public and private property that results in significant costs to the public and individuals.

The primary purpose of flood hazard regulations is to regulate development in the 100-year floodplain to avoid substantial risk and damage to public and private property and loss of life.

The City finds, therefore, that identification, regulation and protection of sensitive areas are necessary to protect the public health, safety and general welfare.

(5) This section of the Redmond Community Development Guide contains standards, guidelines, criteria and requirements intended to identify, analyze, preserve and mitigate potential impacts to the City’s sensitive areas and to enhance and restore degraded resources, such as wetlands, streams or habitat, where possible. The intent of these regulations is to avoid impacts to sensitive areas. In appropriate circumstances, impacts to specified sensitive areas resulting from regulated activities may be minimized, rectified, reduced and/or compensated for, consistent with the requirements of this chapter.

(a) Provide standards, guidelines, and criteria to guide application of these sensitive areas goals and policies when considered with other goals and policies of the Redmond Community Development Guide, including those pertaining to natural features and environmental protection;

(b) Serve as a basis for exercise of the City’s substantive authority under the State Environmental Policy Act (SEPA) and the City’s SEPA rules;

(d) Coordinate environmental review and permitting of proposals to avoid duplication and delay.

(6) For the purposes of this division, “department” shall mean the City of Redmond Department of Planning and Community Development. (Ord. 2180; Ord. 1693. Formerly 20C.40.010)

20D.140.10-020 Applicability – Regulated Activities.

(1) The provisions of this chapter shall apply to any activity that has a potential to significantly adversely impact a sensitive area or its established buffer unless otherwise exempt. Such activities include but are not limited to:

(a) Removing, excavating, disturbing or dredging soil, sand, gravel, minerals, organic matter or materials of any kind;

(e) Constructing, reconstructing, demolishing or altering the size of any structure or infrastructure that results in disturbance of a sensitive area or the addition of any impervious surface coverage to a site;

(f) Destroying or altering vegetation through clearing, grading, harvesting, shading or planting vegetation that would alter the character of a sensitive area;

(g) Activities that result in significant changes in water temperature, physical or chemical characteristics of water sources, including quantity and pollutants; and

(h) Any other activity that has a potential to significantly adversely impact a sensitive area or established buffer not otherwise exempt for the provisions of this chapter.

With regard to flood hazard areas, the provisions of this chapter shall apply to any activity that would result in change to the flood storage capacity of a floodplain or flood fringe area, or cause an increase in the base flood elevation, unless otherwise exempt.

(2) To avoid duplication, the following permits and approvals shall be subject to and coordinated with the requirements of this chapter: clearing and grading; site plan review; general development permit; special development permit; subdivision or short subdivision; building permit; shoreline substantial development; variance; master plan approval; other permits leading to the development or alteration of land; and rezones if not combined with another development permit.

(3) Nonproject actions, including but not limited to rezones, annexations, and the adoption of plans and programs, may, at the City’s direction, perform any studies or evaluations required by this chapter using methodologies and at a level of detail appropriate to the action proposed. (Ord. 1693. Formerly 20C.40.030)

20D.140.10-030 Exemptions.

(1) The following activities shall be exempt from the provisions of this chapter:

(a) Existing and ongoing agricultural activities, provided no alteration of flood storage capacity or conveyance occurs;

(b) Activities involving artificially created wetlands or streams intentionally created from nonwetland sites, including but not limited to grass-lined swales, irrigation and drainage ditches, detention facilities, and landscape features, except wetlands, streams or swales created as mitigation or that provide critical habitat for salmonid fishes;

(c) Activities affecting Type IV wetlands which are individually smaller than 2,500 square feet and/or cumulatively smaller than 10,000 square feet in size;

(d) Activities occurring in areas of 40 percent slope or greater with a vertical elevation change of up to 15 feet may be exempted based upon City review of a soils report prepared by a geologist or geotechnical engineer which demonstrates that no significant adverse impact will result from the exemption;

(e) Normal and routine maintenance, operation and reconstruction of existing roads, streets, utilities and associated rights-of-way and structures, provided that reconstruction of any structures may not increase the impervious area or remove flood storage capacity;

(f) Normal maintenance and repair, and reconstruction or remodeling of residential or commercial structures, or legal pre-existing and on-going uses of the site, provided that reconstruction of any structures may not increase the previous approved building footprint (see subsection (5) below);

(g) Site investigative work and studies necessary for preparing land use applications, including soils tests, water quality studies, wildlife studies and similar tests and investigations, provided that any disturbance of the sensitive area shall be the minimum necessary to carry out the work or studies;

(h) Educational activities, scientific research, and outdoor recreational activities, including but not limited to interpretive field trips, birdwatching, and trails for horseback riding, bicycling and hiking, that will not have a significant adverse effect on the sensitive area;

(i) Emergency activities necessary to prevent an immediate threat to public health, safety or property;

(j) Normal and routine maintenance and operation of existing landscaping and gardens provided they comply with all other regulations in this chapter;

(k) Construction of trails, according to the following criteria: preferably constructed of permeable materials, designed to minimize impact on the sensitive area, and of a maximum trail corridor width of 10 feet;

(l) Minor activities not mentioned above and determined by the Department to have minimal impacts to a sensitive area;

(m) Previously legally filled wetlands or wetlands created after July 1, 1990, that were unintentionally created as a result of the construction of a road, street or highway, or wetlands accidentally created by other human actions within 20 years of the date the development application is filed. The latter shall be documented by the applicant through photographs, statements, and/or other evidence;

(n) Installation, construction, replacement, repair or alteration of utilities and their associated facilities, lines, pipes, mains, equipment or appurtenances in improved City road rights-of-way.

(2) Notwithstanding the exemptions provided by this subsection, any otherwise exempt activities occurring in or near a sensitive area should meet the purpose and intent of RCDG 20D.140.10-010 and should consider on-site alternatives that avoid or minimize significant adverse impacts.

(3) Exempt activities occurring in flood hazard areas shall not alter flood storage capacity or conveyance.

(4) With the exception of subsections (1)(a), (1)(h), (1)(i), and (1)(j), and normal maintenance and repair of residential and commercial structures as in subsection (1)(f) above, no property owner or other entity shall undertake exempt activities prior to providing 10 days’ notice to the City. In case of any question as to whether a particular activity is exempt from the provisions of this section, the City’s determination shall prevail and shall be confirmed in writing within 10 days of receipt of the owner’s or applicant’s letter. Those activities falling under subsection (1)(i) above shall provide telephone or written communication with the Department within 48 hours of the activity notifying such emergency activity was taken.

(5) Structures shall be allowed to reconstruct if destroyed more than 50 percent of its assessed or appraised value (whichever is greater) if located in a buffer. Reconstruction of the structure shall not further encroach into the buffer area or increase the building footprint. Structures that are nonconforming solely due to the provisions of this chapter shall not be governed by RCDG 20F.10.50, Nonconformances. (Ord. 1929; Ord. 1693. Formerly 20C.40.040)

20D.140.10-040 Sensitive Areas Maps.

(1) Sensitive Areas Generally. The approximate location and extent of sensitive areas within the City’s planning area are shown on the sensitive areas maps adopted as part of this chapter. These maps shall be used as a general guide only for the assistance of property owners and other interested parties; boundaries are generalized. The actual type, extent and boundaries of sensitive areas shall be determined in the field by a qualified consultant according to the procedures, definitions and criteria established by this chapter. In the event of any conflict between the sensitive area location or designation shown on the City’s maps and the criteria or standards of this section, the criteria and standards shall prevail. The sensitive area locations are indicated on the following maps included as a part of this division and listed as follows:

(2) Wellhead Protection Zones. Boundaries for wellhead protection zones are delineated in the map “City of Redmond Wellhead Protection Zones” as adopted as part of this chapter and included as part of this division.

(3) Flood Hazard Areas. The City will employ hydrologic models to define the extent of the zero-rise floodway. If the zero-rise floodway has not yet been defined for the property in question, the applicant will be responsible for modeling the base flood elevation and delineating the extent of the zero-rise floodway, consistent with the assumptions in the Bear Creek Basin Plan as adopted by the City. In the absence of a City hydrologic model, FEMA data will be acceptable. (Ord. 2180; Ord. 1693. Formerly 20C.40.050)

20D.140.10-050 Relationship to Other Regulations.

(1) These sensitive area regulations shall apply as an overlay and in addition to zoning, land use and other regulations established by the City of Redmond. In the event of any conflict between these regulations and any other regulations of the City, the regulations which provide greater protection to environmentally sensitive areas shall apply.

(2) Areas characterized by particular sensitive areas may also be subject to other regulations established by this chapter due to the overlap or multiple functions of some sensitive or critical areas. Wetlands, for example, may be defined and regulated according to the wetland, habitat and stream management provisions of this chapter. In the event of any conflict between regulations for particular sensitive areas in this chapter, the regulations which provide greater protection to environmentally sensitive areas shall apply. (Ord. 1693. Formerly 20C.40.060)

20D.140.10-060 Permit Process and Application Requirements.

(1) Pre-Application Conference. All applicants are encouraged to meet with the City prior to submitting an application subject to this section. The purpose of this meeting shall be to discuss the City’s sensitive area requirements, processes and procedures; to review any conceptual site plans prepared by the applicant; to identify potential impacts to sensitive areas and appropriate mitigation measures; and to generally inform the applicant of any Federal or State regulations applicable to the subject sensitive area. Such conference shall be for the convenience of the applicant and any recommendations shall not be binding on the applicant or the City.

(a) Timing of Submittals. A sensitive area report must be submitted to the City for review, if applicable. The purpose of the report is to determine the extent, characteristics and functions of any sensitive areas located on or that have a potential to be significantly adversely impacted by activities on a site where regulated activities are proposed. The report will also be used by the City to assist in the determination of the appropriate sensitive area rating and establishment of appropriate buffer requirements in accordance with RCDG 20D.140.10-080 through 20D.140.10-130.

(b) Sensitive Areas Report Contents. Reports and studies required to be submitted by this chapter shall contain the information indicated in the attachments to the ordinance codified in this chapter applicable to each sensitive area.

(3) Consultant Qualifications and City Review. All reports and studies required of the applicant by this section shall be prepared by a qualified consultant as that term is defined in these regulations. The City may, at its discretion, retain a qualified consultant to review and confirm the applicant’s reports, studies and plans.

(4) Permit Process. This section is not intended to create a separate sensitive areas permit process for development proposals. The City shall consolidate and integrate the review and processing of sensitive areas aspects of proposals with other land use and environmental considerations and approvals. (Ord. 1693. Formerly 20C.40.070)

20D.140.10-070 Classification and Rating of Sensitive Areas.

To promote consistent application of the standards and requirements of this chapter, sensitive areas within the City of Redmond shall be rated or classified according to their characteristics, function and value, and/or their sensitivity to disturbance.

(1) Wetland Classification. Wetlands, as defined by this chapter, shall be designated Type I, Type II, Type III, Type IV and Artificial according to the criteria in this section.

(a) “Type I Wetlands” are those wetlands which meet any of the following criteria:

(i) The presence of species proposed or listed by the Federal government or State of Washington as endangered, threatened, sensitive or monitor, or the presence of critical or outstanding actual or potential habitat for those species; or

(ii) Wetlands having 40 percent to 60 percent open water in dispersed patches with two or more wetland subclasses of vegetation; or

(iii) Wetlands equal to or greater than 10 acres in size and having three or more wetland classes, one of which is open water; or

(iv) High quality examples of a native wetland listed in the Terrestrial and/or Aquatic Ecosystem elements of the Washington Natural Heritage Plan that are presently identified as such or are determined to be of Heritage quality by the Department of Natural Resources; or

(v) The presence of plant associations of infrequent occurrence. These include, but are not limited to, plant associations found in bogs and in wetlands with a coniferous forested wetland class or subclass occurring on organic soils.

(b) “Type II Wetlands” are those wetlands which are not Type I wetlands and meet any of the following criteria:

(ii) Wetlands equal to or less than one acre but greater than one-half acre in size and having three or more wetland classes; or

(iii) Wetlands equal to or less than one acre but greater than one-half acre in size that have a forested wetland class or subclasses.

(c) “Type III Wetlands” are those wetlands that are equal to or less than one acre in size and that have one or two wetland classes and are not rated as Type IV wetlands, or wetlands less than one-half acre in size having either three wetlands classes or a forested wetland class or subclass.

(d) “Type IV Wetlands” are those wetlands that are equal to or less than 2,500 square feet, and that are hydrologically isolated and have only one wetland class which is not forested.

(e) “Artificially Created Wetlands” are those wetlands defined as such in these regulations, and do not include wetlands created as mitigation, and wetlands modified for approved land use activities. Purposeful or accidental creation must be demonstrated to the Committee through documentation, photographs, statements and/or other evidence. Artificial wetlands intentionally created from nonwetland sites for the purposes of wetland mitigation are regulated under this section.

(2) Stream Classification. Streams shall be designated Class I, Class II, Class III, and Class IV according to the criteria in this section. When more than one stream class is present in short alternating segments on the property in question it will be classified according to the stream class which is more restrictive.

(a) “Class I Streams” are those streams identified as “Shorelines of the State” under the City of Redmond Shoreline Master Program.

(b) “Class II Streams” are those natural streams that are not Class I streams and are either perennial or intermittent and have one of the following characteristics:

(c) “Class III Streams” are those natural streams with perennial (year-round) or intermittent flow and are not used by salmonid fish and have no potential to be used by salmonid fish.

(d) “Class IV Streams” are those streams and natural drainage swales with perennial or intermittent flow with channel width less than two feet taken at the ordinary high water mark that are not used by salmonid fish.

(e) “Intentionally Created Streams” are those manmade streams defined as such in these regulations, and do not include streams created as mitigation. Purposeful creation must be demonstrated to the Committee through documentation, photographs, statements and/or other evidence. Intentionally created streams may include irrigation and drainage ditches, grass-lined swales and canals. Intentionally created streams are excluded from regulation under this section, except manmade streams that provide critical habitat for anadromous fish.

(3) Wildlife Habitat Classification. “Critical Habitat” are those habitat areas which meet any of the following criteria:

(a) The documented presence of species proposed or listed by the Federal government or State of Washington as endangered, threatened, sensitive, monitor or priority;

(4) Geologic Hazard Classifications. Geologic hazard areas shall be classified according to the criteria in this section.

(a) Critical Erosion Hazard Areas. Critical erosion hazard areas are lands or areas underlain by soils identified by the U.S. Department of Agriculture Soil Conservation Service (SCS) as having “severe” or “very severe” erosion hazards. This includes, but is not limited to, the following group of soils when they occur on slopes of 15 percent or greater: Alderwood-Kitsap (AkF), Alderwood gravely sandy loam (AgD), Kitsap silt loam (KpD), Everett (EvD) and Indianola (InD).

(b) Landslide Hazard Areas. Landslide hazard areas are classified as “Class I”, “Class II”, “Class III” or “Class IV” as follows:

(ii) Class II/Moderate Hazard: Areas with slopes between 15 percent and 40 percent and that are underlain by soils that consist largely of sand, gravel or glacial till.

(iii) Class III/High Hazard: Areas with slopes between 15 percent and 40 percent that are underlain by soils consisting largely of silt and clay.

(iv) Class IV/Very High Hazard: Areas with slopes steeper than 15 percent with zones of emergent water (e.g., springs or ground water seepage), areas of landslide deposits regardless of slope, and all areas sloping 40 percent or steeper.

(c) Seismic Hazard Areas. Seismic hazard areas are lands that, due to a combination of soil and ground water conditions, are subject to severe risk of ground shaking, subsidence or liquefaction of soils during earthquakes. These areas are typically underlain by soft or loose saturated soils (such as alluvium), have a shallow ground water table and are typically located on the floors of river valleys.

(5) Wellhead Protection Zones. The City of Redmond is classified into four wellhead protection zones based on proximity to and travel time of groundwater to the City’s public water source wells, and are designated using guidance from the Washington Department of Health Wellhead Protection Program pursuant to Chapter 256-290 WAC.

(a) Wellhead Protection Zone 1 represents the land area overlying the six-month time-of-travel zone of any public water source well owned by the City.

(b) Wellhead Protection Zone 2 represents the land area that overlies the one-year time-of-travel zone of any public water source well owned by the City, excluding the land area contained within Wellhead Protection Zone 1.

(c) Wellhead Protection Zone 3 represents the land area that overlies the five-year and 10-year time-of-travel zones of any public water source well owned by the City, excluding the land area contained within Wellhead Protection Zones 1 or 2.

(d) Wellhead Protection Zone 4 represents all the remaining land area in the City, not included in Wellhead Protection Zones 1, 2, or 3.

(b) Flood Fringe. The portion of the floodplain outside of the floodway which is generally covered by flood waters during the base flood; it is generally associated with standing water rather than rapidly flowing water.

(c) Zero-Rise Floodway. The channel of the stream and that portion of the adjoining floodplain which is necessary to contain and discharge the base flood flow without increasing the base flood elevation. The zero-rise floodway will always include the FEMA floodway.

(d) FEMA Floodway. The channel of the stream and that portion of the adjoining floodplain which is necessary to contain and discharge the FEMA base flood flow without increasing the FEMA base flood elevation more than one foot.

(7) Classification of sensitive areas shall be determined by the Committee based on consideration of the following factors:

(c) Consideration of the technical reports submitted by qualified consultants in connection with applications subject to these regulations. (Ord. 2180; Ord. 1693. Formerly 20C.40.080)

20D.140.10-080 Buffer Areas.

(1) The establishment of buffer areas shall be required for all development proposals and activities in or adjacent to sensitive areas. The purpose of the buffer shall be to protect the integrity, function, value and resource of the subject sensitive area, and/or to protect life, property and resources from risks associated with development on unstable or sensitive lands. Buffers shall consist of an undisturbed area of native vegetation established to achieve the purpose of the buffer. If the site has previously been disturbed, the buffer area shall be revegetated pursuant to an approved planting plan. Buffers shall be protected during construction by placement of a temporary barricade, on-site notice for construction crews of the presence of the sensitive area, and implementation of appropriate erosion and sedimentation controls.

(2) Required buffer widths shall reflect the sensitivity of the particular sensitive area and resource or the risks associated with development and, in those circumstances permitted by these regulations, the type and intensity of human activity and site design proposed to be conducted on or near the sensitive area. Buffers or setbacks shall be measured as follows:

(a) Wetland buffers – from the wetland edge as delineated and marked in the field using the Wetland Manual.

(c) Critical landslide hazard areas – from the top and toe and along the sides of the slope. (Ord. 1955; Ord. 1693. Formerly 20C.40.090(05), (10))

20D.140.10-090 Wetland Buffers.


Wetland Type	Maximum Buffer Width (ft)	Minimum Buffer Width (ft)
Type I	150	100
Type II	100	50
Type III	50	25
Type IV	0	0

The City may extend the width of the buffer on the basis of site-specific analysis when necessary to achieve the goals of this chapter.

(2) The maximum buffer width will be established unless the applicant can demonstrate one or both of the following:

(a) The proposed use and/or activities are considered low impact, and may include the following:

(i) Site layout with no parking, outdoor storage, or use of machinery between building and buffer;

(b) Wetland and buffer enhancement is implemented. These include but are not limited to the following:

(i) Enhancement of wildlife habitat by incorporating structures that are likely to be used by wildlife, including wood duck houses, bat boxes, nesting platforms, snags, rootwads/stumps, birdhouses, and heron nesting areas.

(ii) Planting native vegetation that would increase value for fish and wildlife habitat, improve water quality, or provide aesthetic/recreational value.

(3) Wetland buffer widths may be modified by averaging buffer widths as set forth herein.

(a) Buffer width averaging shall be allowed only where the applicant demonstrates to the Committee that the wetland contains variations in sensitivity due to existing physical characteristics, that lower intensity land uses would be located adjacent to areas where buffer width is reduced, that width averaging will not adversely impact the wetland functional values, and that the total area contained within the buffer after averaging is no less than that contained within the standard buffer prior to averaging. Buffer averaging shall not result in buffer width being reduced by more than 25 percent of the required buffer as set forth in the table in subsection 1 of this section and in no case may the buffer be less than 25 feet in width.

(4) Low impact uses and activities which are consistent with the purpose and function of the wetland buffer and do not detract from its integrity may be permitted within the buffer depending on the sensitivity of the wetland. Examples of uses and activities which may be permitted in appropriate cases include preferably pervious trails, viewing platforms, and utility easements; provided, that any impacts to the buffer resulting from such permitted activities shall be mitigated. Uses permitted within the buffer shall be located as far from the wetland as possible.

(5) Storm water management facilities, such as grass lined swales, may not be located within the minimum buffer area as set forth in the table in subsection 1 of this section.

(6) A regulated wetland and its associated buffer shall either be placed in a separate tract on which development is prohibited, protected by execution of an easement, dedicated to a conservation organization or land trust, or similarly preserved through a permanent protective mechanism acceptable to the City. The location and limitations associated with the wetland and its buffer shall be shown on the face of the deed or plat applicable to the property and shall be recorded with the King County Department of Records. (Ord. 1955; Ord. 1693. Formerly 20C.40.090(15)(a))

20D.140.10-100 Stream Buffers.


Stream Class	Maximum Buffer Width (ft)	Minimum Buffer Width (ft)
Class I	150	100
Class II	100	75
Class III	50	25
Class IV	0	0

(2) The maximum buffer width will be established unless the applicant implements one or more enhancement measures. Such measures, listed in order of preference, will be considered in reducing buffer requirements. These include but are not limited to:

(b) Enhancement of fish habitat using log structures incorporated as part of a fish habitat enhancement plan.

(c) Enhancement of wildlife habitat structures that are likely to be used by wildlife, including wood duck houses, bat boxes, nesting platforms, snags, rootwads/stumps, birdhouses, and heron nesting areas.

(i) Planting native vegetation within the buffer area, especially vegetation that would increase value for fish and wildlife, increase stream bank or slope stability, improve water quality, or provide aesthetic/recreational value; or

(ii) Create a surface channel where a stream was previously culverted or piped; or

(iii) Remove or modify existing stream culverts (such as at road crossings) to improve fish passage and flow capabilities; or

(iv) Upgrade retention/detention facilities or other drainage facilities beyond required levels.

(3) No structures or improvements shall be permitted within the stream buffer area, including buildings, decks, docks, except as otherwise permitted or required under the City’s adopted Shoreline Master Program, or under one of the following circumstances:

(a) When the improvements are part of an approved rehabilitation or mitigation plan; or

(b) For construction of new roads and utilities, and accessory structures, when no feasible alternative location exists; or

(iv) Located within the outer half of the buffer, i.e., the portion of the buffer that is farther away from the stream; or

(f) Storm water management facilities, such as grass lined swales, may not be located within the minimum buffer area as set forth in the table in subsection 1 of this section.

(4) The City may extend the width of the buffer on the basis of site-specific analysis when necessary to comply with a basin plan adopted by the City.

(5) Stream buffer widths may be modified by averaging buffer widths as set forth herein.

(a) Buffer width averaging shall be allowed only where the applicant demonstrates to the Committee that the stream contains variations in sensitivity due to existing physical characteristics, that lower intensity land uses would be located adjacent to areas where buffer width is reduced, and that the total area contained within the buffer after averaging is no less than that contained within the standard buffer prior to averaging. Buffer averaging shall not result in the buffer width being reduced by more than 25 percent of the required buffer as set forth in the table in subsection 1 of this section and in no case may the buffer be less than 25 feet in width.

(6) A regulated stream and its associated buffer shall be placed either in a separate tract on which development is prohibited, protected by execution of an easement, dedicated to a conservation organization or land trust, or similarly preserved through a permanent protective mechanism acceptable to the City. The location and limitations associated with the stream and its buffer shall be shown on the face of the deed or plat applicable to the property and shall be recorded with the King County Department of Records. (Ord. 1955; Ord. 1693. Formerly 20C.40.090(15)(b))

20D.140.10-110 Wildlife Habitat Area Buffers.

(1) Buffer widths for critical habitat areas shall be based on consideration of the following factors: species recommendations of the Washington State Department of Wildlife; recommendations contained in the wildlife study submitted by a qualified consultant; and the nature and intensity of land uses and activities occurring on the site and on adjacent sites.

(2) Low impact uses and activities which are consistent with the purpose and function of the habitat buffer and do not detract from its integrity may be permitted within the buffer depending on the sensitivity of the habitat area. Examples of uses and activities which may be permitted in appropriate cases include preferably pervious trails, viewing platforms, storm water management facilities such as grass-lined swales, and utility easements, provided that any impacts to the buffer resulting from permitted facilities shall be mitigated.

(3) Critical habitat areas and their associated buffer shall be placed either in a separate tract on which development is prohibited, protected by execution of an easement, dedicated to a conservation organization or land trust, or similarly preserved through a permanent protective mechanism acceptable to the City. The location and limitations associated with the critical habitat and its buffer shall be shown on the face of the deed or plat applicable to the property and shall be recorded with the King County Department of Records and Elections. (Ord. 1955; Ord. 1693. Formerly 20C.40.090(15)(c))

20D.140.10-120 Critical Landslide Hazard Area Buffers.

(1) Required buffers shall vary between 25 feet and 50 feet in most cases. The width of the buffer shall reflect the sensitivity of the critical landslide hazard area in question and the types and density of uses proposed on or adjacent to the geologic hazard. In determining the appropriate buffer width, the Committee shall consider the recommendations contained in any technical report required by these regulations and prepared by an applicant’s qualified consultant.

(2) Buffers may be reduced to a minimum of 15 feet when the applicant demonstrates through technical studies that the reduction will adequately protect the proposed and surrounding development from the critical landslide hazard. (Ord. 1693. Formerly 20C.40.090(15)(d))

20D.140.10-130 Buffer Width Variances.

Required buffers shall not deny all reasonable use of property. A variance from buffer width requirements may be granted by the City subject to the variance criteria set forth in RCDG Title 20F and upon a showing by the applicant that:

(1) There are special circumstances applicable to the subject property or to the intended use such as shape, topography, location or surroundings that do not apply generally to other properties and which support the granting of a variance from the buffer width requirements; and

(2) Such buffer width variance is necessary for the preservation and enjoyment of a substantial property right or use possessed by other similarly situated property but which because of special circumstances is denied to the property in question; and

(3) The granting of such buffer width variance will not be materially detrimental to the public welfare or injurious to the property or improvement; and

(4) The granting of the buffer width variance will not significantly impact the subject sensitive area. (Ord. 1693. Formerly 20C.40.090(20))

20D.140.10-140 Alteration or Development of Sensitive Areas – Standards and Criteria.

Standards and criteria are set forth in RCDG 20D.140.10-150 through 20D.140.10-240. (Ord. 1693. Formerly 20C.40.100)

20D.140.10-150 General Mitigation Standard.

All significant adverse impacts to sensitive areas functions and values shall be mitigated. Mitigation actions by an applicant or property owner shall occur in the following sequence:

(1) Avoiding the impact altogether by not taking a certain action or parts of actions;

(2) Minimizing impacts by limiting the degree or magnitude of the action and its implementation;

(3) Rectifying the impact by repairing, rehabilitating, or restoring the affected environment;

(4) Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action; and/or

(5) Compensating for the impact by replacing or providing substitute resources or environments. (Ord. 1693. Formerly 20C.40.100(05))

20D.140.10-160 Other Appropriate Mitigation Actions.

Where impacts cannot be avoided, and the applicant has exhausted feasible design alternatives, the applicant or property owner shall seek to implement other appropriate mitigation actions in compliance with the intent, standards and criteria of this chapter. In an individual case, these actions may include consideration of alternative site plans and layouts, reductions in the density or scope of the proposal, and/or implementation of the performance standards listed in RCDG 20D.140.10-140 through 20D.140.10-240 and 20D.140.10-260 through 20D.140.10-320. (Ord. 1693. Formerly 20C.40.100(10))

20D.140.10-170 Alteration of Sensitive Areas.

Alteration of sensitive areas or their established buffers may only be permitted subject to the criteria in RCDG 20D.140.10-180 through 20D.140.10-230. (Ord. 1693. Formerly 20C.40.100(15))

20D.140.10-180 Alteration of Wetlands.

(1) Type I Wetlands: Alterations of Type I wetlands shall be prohibited subject to the reasonable use provisions of this chapter.

(a) Any proposed alteration and mitigation shall comply with the mitigation performance standards and requirements of these regulations; and

(a) The proposed mitigation complies with the mitigation performance standards and requirements of these regulations; and

(b) Where enhancement or replacement is proposed, ratios shall comply with the requirements of RCDG 20D.140.10-250(3)(b). (Ord. 1693. Formerly 20C.40.100(15)(a))

20D.140.10-190 Alteration of Streams.

(1) Relocation of a Class I, II, or III stream in order to facilitate general site design will not be allowed. Relocation of these classes of streams may take place only when it is part of an approved mitigation or rehabilitation plan, and will result in equal or better habitat and water quality, and will not diminish the flow capacity of the stream.

(ii) Culverts will include gradient controls and creation of pools within the culvert for Class II streams where appropriate; and

(iii) Gravel substrate will be placed in the bottom of the culvert to a minimum depth of one foot for Class II streams;

(d) The applicant or successors shall, at all times, keep any culvert free of debris and sediment to allow free passage of water and, if applicable, fish.

(4) The City may require that a stream be removed from a culvert as a condition of approval, unless the culvert is not detrimental to fish habitat or water quality, or removal would be detrimental to fish or wildlife habitat or water quality. (Ord. 1693. Formerly 20C.40.100(15)(b))

20D.140.10-200 Alteration of Wildlife Habitat Areas.

(1) Critical Habitat. Alterations of critical habitat shall be avoided, subject to RCDG 20D.140.10-350, Reasonable Use Provision, or, for public projects, compliance with the exception criteria set forth below for public projects.

(2) Public Projects. When strict application of the wildlife habitat protection requirements of this chapter would prohibit a development proposal by a public agency, the agency may apply for approval to alter the wildlife habitat, subject to the following criteria:

(a) The alteration complies with state and federal laws governing wildlife habitat;

(b) The public project cannot reasonably or effectively proceed without the alteration and no effective alternative sites exist in the vicinity;

(c) The proposal complies with mitigation performance standards as set forth in RCDG 20D.140.10-150, General Mitigation Standard, and RCDG 20D.140.10-250, Mitigation Standards, Criteria and Plan Requirements;

(d) The proposed alteration and mitigation will meet the intent of this chapter to preserve wildlife diversity in the City of Redmond and prevent the extinction of species covered by RCDG 20D.140.10-070(3)(a) and (b), Classification and Rating of Sensitive Areas, from within the City of Redmond and its immediate vicinity. The applicant may be required to monitor the affected species and adjust the required mitigation to meet this goal; and

(e) The public need for the proposed public project outweighs the anticipated adverse impacts on the wildlife habitat and wildlife diversity in Redmond. (Ord. 2095; Ord. 1693. Formerly 20C.40.100(15)(c))

20D.140.10-210 Alteration of Geologic Hazard Areas.

(1) The City shall approve, condition or deny proposals in a geologic hazard area as appropriate based upon the effective mitigation of risks posed to property, health and safety. The objective of mitigation measures shall be to render a site containing a critical geologic hazard site as safe as one not containing such hazard. Conditions may include limitations of proposed uses, modification of density, alteration of site layout and other appropriate changes to the proposal. Where potential impacts cannot be effectively mitigated, or where the risk to public health, safety and welfare, public or private property, or important natural resources is significant notwithstanding mitigation, the proposal shall be denied.

(2) Class IV Landslide Hazard Areas. Development shall be prohibited in Class IV (very high) landslide hazards areas except for the installation and construction of streets and/or utilities, subject to the criteria below. The Technical Committee shall refer the proposed project to the City Council for review and approval.

(a) The proposed street and/or utility is identified in an adopted plan as of October 1, 1997, such as the Comprehensive Plan, Capital Facility Plan, Transportation Improvement Plan or other Utility Facility Plan. As new or amended plans are prepared and adopted, streets and utilities shall be located to avoid impact to Class IV landslide hazard areas. Where no reasonable alternative to locating in Class IV landslide hazard areas exists, review and approval of the plan shall include a discussion of alternatives and rationale for planning streets and utilities in Class IV landslide hazard areas.

(b) Alternative locations, which avoid impact to Class IV landslide hazard areas are evaluated and are determined to be economically or functionally infeasible.

(c) There is a geotechnical evaluation to identify the risks of damage from the proposal, both on-site and off-site, to ascertain that the proposal will not increase the risk of occurrence of the potential geologic hazard; and to identify measures to eliminate or reduce risks.

When no alternative exists, the impact shall be minimized by limiting the magnitude of the proposed construction to the extent possible. Any impacts shall be rectified by repairing, rehabilitating, restoring, replacing or providing substitute resources consistent with the mitigation and performance standards contained in RCDG 20D.140.10-250 and 20D.140.10-260.

(a) For one-story and two-story residential structures, the applicant shall conduct an evaluation of site response and liquefaction potential based on the performance of similar structures under similar foundation conditions; and

(b) For all other proposals, the applicant shall conduct an evaluation of site response and liquefaction potential including sufficient subsurface exploration to provide a site coefficient (S) for use in the static lateral force procedure described in the Uniform Building Code.

(4) When development is permitted in geologic hazard areas by these regulations, an applicant and/or its qualified consultant shall provide assurances which include the following:

(a) A letter from the geotechnical engineer and/or geologist who prepared the studies required by these regulations that risks of damage from the proposal, both on-site and off-site, are minimal subject to the conditions set forth in the report, that the proposal will not increase the risk of occurrence of the potential geologic hazard, and that measures to eliminate or reduce risks have been incorporated into its recommendations;

(b) A legal statement which shall be recorded and noted on the face of the deed or plat, and executed in a form satisfactory to the City, characterizing the site as being located in a geologic hazard area and that there may or may not be risks associated with development of such site; and

(c) Posting of a bond, guarantee or other assurance device approved by the City to cover the cost of monitoring, maintenance and any necessary corrective actions. (Ord. 1955; Ord. 1693. Formerly 20C.40.100(15)(d))

20D.140.10-220 Prohibited Activities in Wellhead Protection Zones.

(1) Land uses or activities for new development or redevelopment that pose a significant hazard to the City’s groundwater resources resulting from storing, handling, treating, using, producing, recycling, or disposing of hazardous materials or other deleterious substances shall be prohibited in Wellhead Protection Zones 1 and 2. These land uses and activities include, but are not limited to:

(a) On-site community sewage disposal systems, as defined in Chapter 248-272 WAC;

(b) Hazardous liquid pipelines as defined in Chapter 81.88 RCW and Chapter 20A.20 RCDG;

(h) Hazardous waste treatment, storage, and disposal facilities except those defined under permit by rule for industrial wastewater treatment processes per WAC 173-303-802(5)(c);

(i) Chemical manufacturing, including but not limited to organic and inorganic chemicals, plastics and resins, pharmaceuticals, cleaning compounds, paints and lacquers, and agricultural chemicals;