To promote consistent application of the standards and requirements of this chapter, environmentally sensitive areas within the town shall be rated or classified according to their characteristics, functions and values, and/or their sensitivity to disturbance.

A. 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. Wetland classes as that term is used in this subsection are defined in Section 16.10.340.

1. "Type I wetlands" are those wetlands which meet any of the following criteria:

a. Wetlands which include the presence of species proposed or listed by the federal government or state of Washington as endangered, threatened, environmentally sensitive or monitor, or the presence of critical or outstanding actual or potential habitat for those species; or

b. Wetlands having forty percent to sixty percent open water in dispersed patches with two or more wetland subclasses of vegetation; or

c. 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 Rsources; or

d. 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.

2. "Type II wetlands" are those wetlands which are not Type I wetlands and meet any of the following criteria:

a. Wetlands greater than one acre in size;

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

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

3. "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.

4. "Type IV wetlands" are those wetlands that are equal to or less than two thousand five hundred square feet, and that are hydrologically isolated and have only one wetland class which is not forested.

5. "Artificially created wetlands" are those wetlands which were deliberately or accidentally created for landscaping and or stormwater purposes 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 town 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.

B. 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 alternating segments on the property in question it will be classified according to the stream class which is more restrictive.

1. "Class I streams" are those streams identified as "Shorelines of the State" under the Snohomish County shoreline master program, adopted by reference by the town, as amended.

2. "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:

a. Salmonid fish use;

b. Potential for salmonid fish use or benefit; or

c. Significant recreational value.

3. "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, but which contribute water to streams or waterbodies used by threatened or endangered species.

4. "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 and which are not hydrologically connected to waterbodies used by threatened or endangered species.

5. "Intentionally created streams" are those man-made streams purposefully created, and do not include streams created as mitigation. Purposeful creation must be demonstrated to the town 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 man-made streams that provide or contribute to critical habitat for anadromous fish and/or threatened or endangered species.

C. Fish and Wildlife Habitat Classification. "Critical habitat" includes those areas which meet any of the following criteria:

1. The documented presence of species proposed or listed by the federal government or state of Washington as endangered, threatened, environmentally sensitive, monitor or priority;

2. The presence of heron rookeries or raptor nesting trees;

3. Type I-II wetlands and their buffers as defined in these regulations; or

4. Class I-II streams and their buffers, as defined in these regulations;

5. Species of local significance as identified in the town comprehensive plan;

6. Areas of previously undisturbed native vegetation and or stands of significant trees which provide a corridor between any of the critical habitat areas listed in subsections (C)(1) through (C)(5) of this section.

D. Geologic Hazard Classifications. Geologic hazard 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") as having "severe" or "very severe" erosion hazards.

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 less than fifteen percent;

b. Class II/Moderate Hazard. Areas with slopes between fifteen percent and forty 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 fifteen percent and forty percent that are underlain by soils consisting largely of silt and clay or by soils that have sand over clay;

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

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.

E. Aquifer Recharge and Wellhead Protection Areas. Aquifer recharge and wellhead protection areas shall be classified as "low," "medium" and "high" significance based on the soil and groundwater conditions and risks to drinking water. Classification depends on the combined effects of hydrogeological susceptibility to contamination and contaminant loading potential, and presence of municipal water well head areas, as follows:

1. Low Significance/Low Susceptibility Recharge Areas. Upland areas underlain by soils consisting largely of silt, clay or glacial till;

2. Medium Significance/Moderate Susceptibility Recharge Areas. Upland areas underlain by soils consisting largely of sand and gravel;

3. High Significance/High Susceptibility Recharge Areas. Wellhead protection areas and areas underlain by soils consisting largely of sand and gravel in which there is a predominantly downward or lateral component to groundwater flow, and which serve as a source of drinking water.

F. Classification of environmentally sensitive areas shall be determined by the town based on consideration of the following factors:

1. Maps adopted pursuant to this chapter;

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

3. Consideration of the technical reports submitted by qualified consultants in connection with applications subject to these regulations. (Ord. 00-387 §1(part), 2000)