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

B. Classification of critical areas shall be determined by the director based on consideration of the following factors and in the following order:

1. Consideration of the technical reports submitted by qualified consultants in connection with applications subject to these regulations;

2. Application of the criteria contained in these regulations; and

3. Critical areas maps maintained by the department of community development.

C. Wetland Classification. Wetlands shall be rated according to the Washington Department of Ecology wetland rating system, as set forth in the Washington State Wetland Rating System for Western Washington: 2014 Update (Ecology Publication No. 14-06-029, or as revised and approved by Ecology). Wetland rating categories shall not change due to illegal modifications.

1. “Category I wetlands” include wetlands which: represent unique or rare wetland types, are more sensitive to disturbance than most wetlands, are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime, or provide a high level of functions, as indicated by a rating system score of 23 points or more on the classification system referenced above.

2. “Category II wetlands” provide high levels of some functions, being difficult, though not impossible to replace, and have a moderately high level of functions, scoring between 20 and 22 points.

3. “Category III wetlands” have a score between 16 and 19 points, generally have been disturbed in some way and are often less diverse or more isolated from other natural resources in the landscape than Category II wetlands.

4. “Category IV wetlands” have the lowest levels of functions, scoring fewer than 16 points and are often heavily disturbed. These are wetlands that should be able to be replaced, or in some cases be improved. However, experience has shown that replacement cannot be guaranteed in any specific case. These wetlands may provide some important functions, and should be protected to some degree.

5. “Artificially created wetlands” are purposefully created landscape features, ponds and storm water detention or retention facilities. Artificially created wetlands do not include wetlands created as mitigation, and wetlands modified for approved land use activities. Purposeful creation must be demonstrated to the director through documentation, photographs, statements and/or other evidence. Artificial wetlands intentionally created from nonwetland sites are excluded from regulation under this section.

D. Stream Classification. Streams shall be classified according to the water typing system as provided in WAC 222-16-030, as amended, and designated as Type S, Type F, Type Np, and Type Ns.

1. “Type S streams” are those natural streams identified as “shorelines of the state” under Chapter 90.58 RCW and the city of Auburn shoreline master program.

2. “Type F streams” are those natural streams that are not Class I streams and are either perennial or intermittent and have one of the following characteristics:

a. Contain fish habitat; or

b. Has significant recreational value, as determined by the director.

3. “Type Np streams” are those natural streams with perennial (year-round) or intermittent flow and do not contain fish habitat.

4. “Type Ns streams” are those natural streams and drainage swales with channel width less than two feet taken at the ordinary high water mark, that do not contain fish habitat.

5. “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 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,” as designated by federal or state agencies, for salmonids.

E. Wildlife Habitat Classification. Wildlife habitat areas shall be classified as critical, secondary or tertiary according to the criteria in this section:

1. “Critical habitat” are those habitat areas which meet any of the following criteria:

a. The documented presence of species or habitat listed by federal or state agencies as “endangered,” “threatened,” or “sensitive”; or

b. The presence of unusual nesting or resting sites such as heron rookeries;

c. Category I wetlands, as defined in these regulations; or

d. Type S streams, as defined in these regulations.

2. “Secondary habitat” is habitat which is valuable to fish and wildlife and supports a wide variety of species due to its undisturbed nature, a diversity of plant species and structure, presence of water, or the area’s size, location, or seasonal importance.

3. “Tertiary habitat” is habitat which is not classified as critical or secondary. It is habitat which, while supporting some wildlife and performing other valuable functions, does not currently possess essential characteristics necessary to support diverse wildlife communities. Tertiary habitat also includes habitat which has been created purposefully by human actions to serve other or multiple purposes, such as open space areas, landscape amenities, and detention facilities.

F. Aquifer Recharge Areas. The following areas are hereby designated as aquifer recharge areas subject to review under this chapter:

1. Type I.

a. Sole source aquifers and wellhead protection areas designated pursuant to the Federal Safe Drinking Water Act.

b. Areas established for special protection pursuant to a groundwater management program as described by Chapters 90.44, 90.48 and 90.54 RCW and Chapters 173-100 and 173-200 WAC.

c. Any other area meeting the definition of “areas with a critical recharging effect on aquifers used for potable water” as described in Chapter 365-190 WAC and the Auburn comprehensive plan, including groundwater protection areas Nos. 1 through 3 as designated in the “Water Resource Protection Report” prepared for the city by the Pacific Groundwater Group, December 2000.

2. Type II.

a. Groundwater protection area No. 4 as designated in the “Water Resource Protection Report” prepared for the city by the Pacific Groundwater Group, December 2000.

b. Any other area within the city that is not otherwise designated or that is added to the city via annexation shall be treated as a Type II aquifer recharge area.

G. Geologically Hazardous Classifications. Geologically hazardous areas shall be classified according to the criteria in this section:

1. 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), now known as the Natural Resources Conservation Service, as having “severe” or “very severe” erosion hazards. This includes the following group of soils when they occur on slopes of 15 percent or greater: Alderwood-Kitsap (AkF), Alderwood gravelly sandy loam (AgD), Kitsap silt loam (KpD), Everett (EvD), and Indianola (InD).

2. Landslide Hazard Areas. Landslide hazard areas are classified as Class I, Class II, Class III, or Class IV as follows:

a. Class I/Low Hazard. Areas with slopes of 15 percent or less.

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

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

d. Class IV/Very High Hazard. Areas with slopes steeper than 15 percent with mappable zones of emergent water (e.g., springs or groundwater seepage), areas of known (mappable) landslide deposits regardless of slope, and all areas with slopes 40 percent or greater.

3. Seismic Hazard Areas. Seismic hazard areas are lands that, due to a combination of soil and groundwater 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 groundwater table and are typically located on the floor of river valleys. (Ord. 6733 § 3 (Exh. B), 2019; Ord. 6287 § 2, 2010; Ord. 5894 § 1, 2005.)