The City of Auburn contains numerous areas that can be identified and characterized as critical or environmentally sensitive. These areas are designated pursuant to Washington State law (RCW 36.70A.060 and WAC 197-11-908) and the Auburn City Code (ACC) Chapter 16.10 (not supported in Internet Explorer browser). These critical areas perform a variety of valuable and biological and physical functions that benefit the City and its residents. Alteration of certain critical areas may pose a threat to public safety, to public and private property, or to the environment. Identification, regulation, and protection of critical areas are necessary to protect the public health, safety, and general welfare.

The City regulates six types of critical areas through Chapter 16.10 ACC: 

• Wetlands
• Streams
• Wildlife habitat areas
• Ground water protection areas
• Geologic Hazard areas
• Flood Hazard areas

Wetlands
Wetlands are areas where water covers or saturates the soil; frequently this water is only visible or apparent during the spring and may be dry during other seasons. Wetlands are commonly referred to as swamps, marshes, and bogs and may occur near streams, in depressions, or simply isolated from other critical areas. Wetlands are classified into four types, based on a combination of habitat, water quality, and flood-flow-reduction functions. 

Wetlands provide breeding and foraging habitat for fish and wildlife; natural water quality improvement (e.g. purification); flood protection through storage and slow release rates; shoreline stabilization and erosion protection; and opportunities for passive recreation and visual interest. Many of the City’s urban wetlands are heavily disturbed, but still provide valuable functions.

More information on wetlands can be found on the WA State Dept. of Ecology’s Wetlands and on the U.S. EPA Wetland Protection and Restoration Website. 

Streams
Streams are areas natural channels where water flows at least part of the year. Streams are classified into four types, based on their flow and capacity to support fish. Artificial channels (e.g., ditches) are generally not protected, unless they are fish-bearing or convey a stream that previously occurred naturally in that location. 

A healthy stream needs healthy riparian areas along its banks and floodplain areas. Riparian vegetation provides shade, which in-turn protects water quality and regulates water temperature; retains soil, which prevents erosion that can affect fish spawning and feeding areas; and provides fish and wildlife habitat. Streams also help contain and convey storm and flood waters. 

Wildlife Habitat Areas
Wildlife habitat areas provide food, water, nesting and rearing areas, cover, and movement opportunities for fish and wildlife. These areas are often located in conjunction with other critical areas such as wetlands and streams. Wildlife habitat areas are classified into three types, based on the amount of support they provide. 

Groundwater Protection Areas
Groundwater protection areas are designed to prevent contamination of groundwater that is used for drinking water; these areas are classified into four types and is generally based on the time-of-travel for groundwater. 

Geologic Hazard Areas
Geologic hazard areas contain slopes that may be susceptible to slides, erosion, earthquakes or other geological events depending on factors such as slope, underlying soils, and the presence of groundwater; these areas are classified into three types. 

Floodplain Management & Development
Flood hazard areas are those subject to 100-year floods and areas that are within the storage floodway of the Green River / White River / Mullen Slough / Mill Creek as identified on the FEMA Flood Insurance Rate Maps. 

Applicability of Regulations
Because of the recognized value and benefit of these critical areas, City regulations apply to these areas when the definition of a critical area is met.  Chapter 16.10 ACC (not supported in Internet Explorer browser) contains provisions which apply to any activity that potentially affects or disturbs a critical area or its buffer. Such activities include, but are not limited to:

• excavation
• filling
• clearing
• planting
• construction
• demolition
• the addition of structures, including but not limited to buildings
• fences, decks, etc.
• the release of contaminants

The City’s eGIS (online mapping tool) contains inventory-level map data depicting the general location of critical areas. The critical areas map data is available for reference at the Planning Services Division at the Customer Service Center located at One E Main St. in downtown Auburn.  These maps can be used for informational purposes as a general guide only for the assistance of property owners and other interested parties; the boundaries and locations of the critical areas shown are generalized and are for reference only. The actual presence or absence, type, extent, boundaries, and classification of critical areas on a specific site shall be identified in the field by a qualified consultant, and determined by the City according to the procedures, definitions, and criteria established by the City’s regulations. 

Informational Materials