16.50.270 General Requirements Pertaining to Wetlands.
(1) Activities in Wetland Areas. A proposed activity may only be permitted in a wetland or wetland buffer if the applicant can show that the activity, including associated mitigation measures, will not degrade the functions and values of the wetland and other critical areas.
(2) Wetland Buffers. Unless otherwise provided for in this Chapter, wetland buffers are required.
(a) Standard Buffer Widths. The standard buffer widths presume the existence of a relatively intact native vegetation community in the buffer zone adequate to protect the wetland functions and values at the time of the proposed activity. If the vegetation is inadequate then the buffer width shall be increased or the buffer should be planted to maintain the standard width. Required standard wetland buffers, based on wetland category and land use intensity, are set forth in Tables 16.50.1 and 16.50.2 below.
Category of Wetland | Low Intensity Land Use | Moderate Intensity Land Use | High Intensity Land Use |
|---|---|---|---|
IV | 25 feet | 40 feet | 50 feet |
III | 75 feet | 110 feet | 150 feet |
II | 100 feet | 150 feet | 200 feet |
I | 125 feet | 190 feet | 250 feet |
Land Use Intensity | Types of Land Use |
|---|---|
High | • Commercial |
• Urban | |
• Industrial | |
• Institutional | |
• Retail sales | |
• Residential (more than one dwelling unit per acre) | |
• Conversion to high-intensity agriculture (dairies, nurseries, greenhouses, growing and harvesting crops requiring annual tilling, and raising and maintaining animals, etc.) | |
• High-intensity recreation (golf courses, ball fields, etc.) | |
• Hobby farms | |
Moderate | • Residential (one dwelling unit per acre or less) |
• Moderate-intensity open space (parks with biking, jogging, etc.) | |
• Conversion to moderate-intensity agriculture (orchards, hay fields, etc.) | |
• Building of logging roads | |
• Utility corridor or right-of-way shared by several utilities and including access/maintenance road | |
Low | • Forestry (cutting of trees only) |
• Low-intensity open space (hiking, bird-watching, preservation of natural resources, etc.) | |
• Utility corridor without a maintenance road and little or no vegetation management |
(b) Measurement of Wetland Buffers. All buffers shall be measured from the wetland boundary as surveyed in the field. The width of the wetland buffer shall be determined according to the wetland category and the proposed land use. 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.
(c) Increased Wetland Buffer Width. The Director of Community Development may require increased buffer width in accordance with the critical area report and the most current, accurate, and complete scientific and technical information available on a case by case basis when a larger buffer is necessary to protect wetland functions and values based on site-specific characteristics. This determination shall be based on one or more of the following criteria:
(i) a larger buffer is needed to protect other critical areas;
(ii) the buffer or adjacent uplands has an overall slope steeper than 15 percent or is susceptible to erosion and standard erosion control measures will not prevent adverse impacts to the wetland; or
(iii) the buffer area has minimal vegetative cover, although implementation of a buffer planting plan may substitute for increasing the buffer width.
In no case shall wetland buffers be increased to a width greater than two times that of the standard required buffer.
(d) Reduced Wetland Buffer Width. The Director of Community Development may allow the standard wetland buffer width to be reduced in accordance with the critical area report and the most current, accurate, and complete scientific and technical information available on a case-by-case basis when it is determined that a smaller area is adequate to protect the wetland functions and values based on site-specific characteristics. This determination shall be supported by documentation showing that a reduced buffer is adequate based on all of the following criteria:
(i) requiring the standard buffer poses an extraordinary hardship on the landowner;
(ii) the existing buffer area is well-vegetated with native species and has an overall slope of less than ten percent; and
(iii) no direct or indirect, short-term or long term, adverse impacts to wetlands will result from the proposed activity.
In no case shall the standard buffer width be reduced to less than either 75 percent of the required width or 75 feet for Category I and II wetlands, 50 feet for Category III wetlands, and 25 feet for Category IV wetlands, whichever is greater, unless the applicant demonstrates an acceptable reasonable use as described in 16.50.120.
(e) Wetland Buffer Width Averaging. The Director of Community Development may allow modification of the standard wetland buffer width in accordance with the critical area report and the most current, accurate, and complete scientific and technical information available on a case-by-case basis by averaging buffer widths. Averaging of buffer widths may only be allowed where a qualified wetlands professional demonstrates that:
(i) it will not reduce wetland functions or values;
(ii) the wetland contains variations in sensitivity due to existing physical characteristics or the character of the buffer varies in slope, soils, or vegetation, and the wetland would benefit from a wider buffer in places and would not be adversely impacted by a narrower buffer in other places;
(iii) the total area contained in the buffer area after averaging is no less than that which would be contained within the standard buffer; and
(iv) the buffer at its narrowest point is never less than either 75 percent of the required width or 75 feet for Category I and II wetlands, 50 feet for Category III wetlands, and 25 feet for Category IV wetlands, whichever is greater, unless the applicant demonstrates an acceptable reasonable use as described in 16.50.120.
(f) Buffers for Mitigation Shall be Consistent. All mitigation sites shall have buffers consistent with the buffer requirements of this Chapter.
(g) Buffer Conditions Shall be Maintained. Except as otherwise specified or allowed in accordance with this Chapter, wetland buffers shall be retained in their natural condition.
(h) Functionally Isolated Buffer Areas. Areas that are functionally separated from a wetland and do not provide protection to the wetland from potential adverse impacts due to preexisting roads, facilities, or vertical separation, shall be excluded from buffers otherwise required by this chapter.
(i) Allowed Buffer Uses. In addition to those uses identified in Subsection 16.50.110(3), the following uses may be allowed within a wetland buffer in accordance with the review procedures of this Chapter, provided they are not prohibited by any other applicable law and they are conducted in a manner so as to minimize impacts to the buffer and adjacent wetland:
(i) Passive Recreation Facilities. Passive recreation facilities designed and in accordance with an approved critical area report, including:
aa. Walkways and trails, provided that those pathways are limited to minor crossings having no adverse impact on water quality. They should be generally parallel to the perimeter of the wetland, located only in the outer 25 percent of the wetland buffer area, and located to avoid removal of significant trees. They should be limited to pervious surfaces no more than five feet in width for pedestrian use only. Raised boardwalks utilizing non-treated pilings may be acceptable.
bb. Wildlife-viewing structures.
(ii) Utility Drilling. Drilling for utilities/utility corridors under a buffer, with entrance/exit portals located completely outside of the wetland buffer boundary, provided that the drilling does not interrupt the ground water connection to the wetland or percolation of surface water down through the soil column. Specific studies by a hydrologist are necessary to determine whether the ground water connection to the wetland or percolation of surface water down through the soil column is disturbed.
(iii) Buffer Enhancement. Enhancement of a wetland buffer through the removal of non-native invasive plant species. Removal of invasive plant species shall be restricted to hand removal. All removed plant material shall be taken away from the site and appropriately disposed of. Plants that appear on the Washington State Noxious Weed Control Board list of noxious weeds must be handled and disposed of according to a noxious weed control plan appropriate to that species. Revegetation with appropriate native species at natural densities is allowed in conjunction with removal of invasive plant species.
(iv) Stormwater Management Facilities. Stormwater management facilities are limited to stormwater dispersion outfalls and bioswales. They may be allowed within the outer 25 percent of the buffer of Category III or IV wetlands only, provided that:
aa. no other location is feasible; and
bb. the location of such facilities will not degrade the functions or values of the wetland; and
cc. stormwater management facilities are not allowed in buffers of Category I or II wetlands.
(v) Non-Conforming Uses. Repair and maintenance of non-conforming uses or structures, where legally established within the buffer, provided they do not increase the degree of nonconformity.
(3) Subdivisions. The subdivision and short subdivision of land in wetlands and associated buffers is subject to the following:
(a) Land that is located wholly within a wetland or its buffer may not be subdivided.
(b) Land that is located partially within a wetland or its buffer may be divided provided that an accessible and contiguous portion of each new lot:
(i) is located outside of the wetland and its buffer; and
(ii) meets the minimum lot size requirements of the city zoning code (Title 17).
(c) Access roads and utilities serving a proposed subdivision or other property may be permitted within the wetland and associated buffers only if the Director of Community Development determines that no other feasible alternative exists and these facilities are otherwise established consistent with the provisions of this Chapter.
(4) Signs and Fencing of Wetlands.
(a) Temporary Markers. The outer perimeter of the wetland or buffer and the limits of those areas to be disturbed pursuant to an approved development permit shall be marked in the field in such a way as to ensure that no unauthorized intrusion will occur prior to the commencement of permitted activities. This temporary marking shall be maintained throughout construction, and shall not be removed until permanent signs, if required, are in place.
(b) Permanent Signs. As a condition of any development permit, the Director of Community Development may require the applicant to install permanent signs along the boundary of a wetland and/or buffer. If required, permanent signs shall be made of a metal face and attached to a metal post, or another material of equal durability. Signs must be posted at an interval of one per lot or every 50 linear feet, whichever yields the greater amount of signs, and must be maintained by the property owner in perpetuity. The sign shall be worded as follows or with alternative language approved by the director:
“Protected Wetland Area
Do Not Disturb Contact City of Pullman
Regarding Uses and Restrictions”
(c) Fencing.
(i) As a condition of any development permit, the Director of Community Development may require the applicant to install a permanent fence at the edge of the wetland buffer, when fencing will prevent future impacts to the wetland.
(ii) The applicant shall be required to install a permanent fence around the wetland or buffer when domestic grazing animals are present or may be introduced on site.
(iii) Fencing installed as part of a proposed activity or as required in this Paragraph shall be designed so as to not interfere with species migration, including fish runs, and shall be constructed in a manner that minimizes impacts to the wetland and associated habitat.
(iv) At no time shall treated wood posts (e.g., creosote) be allowed in wetland areas or in adjacent uplands to prevent chemicals from migrating into the wetland. (Ord. 21-15 §6, 2021; Ord. 19-6 §14, 2019; Ord. 03-18 §28, 2003).