14.50.914 Wetland buffers – Dimensions

14.50.914 Wetland buffers – Dimensions.

A. Wetland buffers shall be required for all regulated activities adjacent to regulated wetlands. Any wetland created, restored, or enhanced as compensation for approved wetland alterations shall also include the standard buffer required for the category of the created, restored or enhanced wetland. Buffers shall not include areas that are disconnected functionally and effectively from the wetland by a road or other substantially developed surface of sufficient width and with use characteristics such that buffer functions are not provided.

B. The buffer standards required by this chapter presume the existence of a dense vegetation community in the buffer adequate to protect the wetland functions and values. When a buffer lacks adequate vegetation, the shoreline administrator may increase the standard buffer, require buffer planting or enhancement and/or deny a proposal for buffer reduction or buffer averaging.

1. The wetland buffer widths are based on wetland category, intensity of impacts and wetland functions or special characteristics. Wetland buffer widths shall be determined according to the land use intensities and wetland characteristics of Appendix 2: Table A2-2 and Appendix 2: Table A2-3.

2. The buffer is to be vegetated with native plant communities that are appropriate for the site conditions. If vegetation in the buffer is disturbed (grazed or mowed), proponents planning changes to land that will increase impacts to wetlands need to rehabilitate the buffer with native plant communities that are appropriate for the site conditions. The width of the buffer is measured in horizontal distance. All buffers shall be measured from the wetland boundary as surveyed in the field.

3. The buffer for a wetland created, restored, or enhanced as compensation for wetland alterations shall be the same as the buffer required for the category of the created, restored or enhanced wetland.

Appendix 2: Table A2-2: Types of Proposed Land Use That Can Result in High, Moderate, and Low Levels of Impacts to Adjacent Wetlands
Level of Impact from Proposed Change in Land Use	Types of Land Uses
Low	• Forestry • Low-intensity open space (hiking, bird watching, preservation of natural resources, etc.) • Unpaved trails • Utility corridor without maintenance road and little to no vegetation management
Moderate	• Residential (one unit/acre or less) • Moderate-intensity open space (parks with biking, jogging, etc.) • Paved driveways and gravel driveways serving three or more residences • Paved trails
High	• Commercial • Urban • Industrial • Institutional • Retail sales • Residential (more than one unit/acre) • High-intensity recreation (golf courses, ball fields, etc.)

Appendix 2: Table A2-3: Width of Buffers Needed to Protect Wetlands
Wetland Characteristics	Buffer Width by Impact of Proposed Land Use	Other Measures Recommended for Protection
Category IV Wetlands (For wetlands scoring less than 16 points for all functions)
Score for all 3 basic functions is less than 16 points	Low – 25 ft. Moderate – 40 ft. High – 50 ft.	None
Category III Wetlands (For wetlands scoring 16 – 19 points for all functions)
High level of function for habitat (score for habitat 8 – 9 points)	Low – 150 ft. Moderate – 225 ft. High – 300 ft.	Maintain connections to other habitat areas
Moderate level of function for habitat (score for habitat 5 – 7 points)	Low – 75 ft. Moderate – 110 ft. High – 150 ft.	None
Not meeting above characteristics	Low – 40 ft. Moderate – 60 ft. High – 80 ft.	None
Category II Wetlands (For wetlands that score 20 – 22 points for all functions, or having the “Special Characteristics” identified in the rating system)
High level of function for habitat (score for habitat 8 – 9 points)	Low – 150 ft. Moderate – 225 ft. High – 300 ft.	Maintain connections to other habitat areas
Moderate level of function for habitat (score for habitat 5 – 7 points)	Low – 75 ft. Moderate – 110 ft. High – 150 ft.	None
High level of function for water quality improvement and low for habitat (score for water quality 8 – 9 points; habitat less than 5 points)	Low – 50 ft. Moderate – 75 ft. High – 100 ft.	No additional surface discharges of untreated run-off
Estuarine	Low – 75 ft. Moderate – 110 ft. High – 150 ft.	None
Not meeting above characteristics	Low – 50 ft. Moderate – 75 ft. High – 100 ft.	None
Category I Wetlands (For wetlands that score 23 points or more for all functions, or having the “Special Characteristics” identified in the rating system)
Natural Heritage wetlands	Low – 125 ft. Moderate – 190 ft. High – 250 ft.	No additional surface discharges to wetland or its tributaries; No septic systems within 300 ft. of wetland; Restore degraded parts of buffer
Bogs	Low – 125 ft. Moderate – 190 ft. High – 250 ft.	No additional surface discharges to wetland or its tributaries; Restore degraded parts of buffer
Forested	Buffer width based on score for habitat functions or water quality functions	If forested wetland scores high for habitat, need to maintain connections to other habitat areas
Estuarine	Low – 100 ft. Moderate – 150 ft. High – 200 ft.	None
High level of function for habitat (score for habitat 8 – 9 points)	Low – 150 ft. Moderate – 225 ft. High – 300 ft.	Restore degraded parts of buffer; Maintain connections to other habitat areas
Moderate level of function for habitat (score for habitat 5 – 7 points)	Low – 75 ft. Moderate – 110 ft. High – 150 ft.	None
High level of function for water quality improvement (8 – 9 points) and low for habitat (less than 5 points)	Low – 50 ft. Moderate – 75 ft. High – 100 ft.	No additional surface discharges of untreated runoff
Not meeting above characteristics	Low – 50 ft. Moderate – 75 ft. High – 100 ft.	None

D. Where lands within the wetland buffer have an average continuous slope of twenty (20) percent to thirty-five (35) percent and the required buffer width is less than one hundred (100) feet, the buffer shall increase to a greater dimension by thirty (30) percent. In all cases, where slopes within the buffers exceed thirty-five (35) percent, the buffer shall extend twenty-five (25) feet beyond the top of the bank of the sloping area or if a buffer associated with a geological hazard is present, to whichever extent is greater.

E. Where other critical areas defined in this chapter fall within the wetland buffer, the buffer dimension shall be the most expansive of the buffers applicable to any applicable critical area.