Wetlands are those areas that are inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. Wetlands may include those artificial wetlands intentionally created from nonwetland areas to mitigate conversion of wetlands.
Wetlands do not include those artificial wetlands intentionally created from nonwetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands created after July 1, 1990, that were unintentionally created as a result of the construction of a road, street, or highway.
(1) Wetland Delineation. Wetlands shall be delineated in accordance with the requirements of RCW
36.70A.175. Unless otherwise provided for in this chapter, all areas within the county determined to be wetlands in accordance with the U.S. Army Corps of Engineers Wetlands Delineation Manual, 1987 Edition, and the Western Mountains, Valleys, and Coast Region Supplement (Version 2.0), 2010 or as revised, are hereby designated critical areas and are subject to the provisions of this article.
(2) Wetland Rating. Wetlands shall be rated based on categories that reflect the functions and values of each wetland. Wetland categories shall be based on the criteria provided in the Washington State Wetland Rating System for Western Washington, revised 2014, and as amended thereafter, as determined using the appropriate rating forms and associated figures contained in that publication. These categories are generally defined as follows:
(a) Category I. These wetlands are: (i) relatively undisturbed estuarine wetlands larger than one acre; (ii) wetlands of high conservation value that are identified by scientists of the Washington Natural Heritage Program/Washington Department of Natural Resources; (iii) bogs; (iv) mature and old-growth forested wetlands larger than one acre; (v) wetlands in coastal lagoons; (vi) wetlands that perform many functions well (scoring a total of 23 or more points). These wetlands: (i) represent unique or rare wetland types; (ii) are more sensitive to disturbance than most wetlands; (iii) are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or (iv) provide a high level of functions.
(b) Category II. These wetlands are: (i) estuarine wetlands smaller than one acre or disturbed estuarine wetlands larger than one acre or (ii) wetlands with a moderately high level of functions (scoring between 20 and 22 points total).
(c) Category III. These wetlands are (i) those with moderate level of functions (scoring between 16 and 19 points total) or (ii) those that can often be adequately replaced with a well-planned mitigation project. Wetlands scoring between 16 and 19 points generally have been disturbed in some ways and are often less diverse or more isolated from other natural resources in the landscape than Category II wetlands.
(d) Category IV. These wetlands have the lowest levels of functions (scoring 15 or fewer total points) and are often heavily disturbed. These wetlands likely could be replaced or improved in some cases. Replacement cannot be guaranteed in any specific case. These wetlands may provide some important functions, so they should be protected to some degree.
(3) Category IV wetlands that are non-federally regulated and not associated with a riparian area and less than one-tenth acre (4,356 square feet) shall be exempt from the requirements of this article when all of the following criteria are met:
(a) The wetland does not provide significant breeding habitat for native amphibian species. Breeding habitat is indicated by adequate and stable seasonal inundation, presence of thin-stemmed emergent vegetation, and clean water;
(b) The wetland does not have unique characteristics that would be difficult to replace through standard compensatory mitigation practices;
(c) The wetland is not located within a fish and wildlife habitat conservation area (FWHCA) or a FWHCA buffer as defined in Article VI of this chapter, and is not integral to the maintenance of habitat functions of an FWHCA;
(d) The wetland is not located within a floodplain;
(e) The wetland is not within the jurisdiction of the county shoreline master program;
(f) The wetland is not part of a mosaic of wetlands and uplands, as determined using the guidance provided in the wetland rating system; and
(g) The wetland does not score five or more points for habitat functions (based on the 2014 version of the Washington Department of Ecology Wetland Rating System, or as amended by Washington Department of Ecology).
In addition, mitigation in the form of enhancement or expansion of another part of the buffer should be considered in order to offset any expansion of a nonconforming use or structure. |
Wetlands less than one-tenth acre that meet the above criteria shall not be filled or otherwise altered. This exemption does not allow for unmitigated alteration of wetland area or functions. Alteration of any wetland, including wetlands less than one-tenth of an acre, shall require mitigation. |
(4) General. Application for a project on a parcel of real property containing a designated wetland shall adhere to the requirements in this section.
(a) Types of Wetland Evaluations. An applicant submitting an application for a development, use, or activity on lands determined to be wetland shall also submit, and have approved, a wetland evaluation prepared based on results of an on-site field investigation conducted by a qualified wetland professional using wetland delineation manuals specified in this section. The wetland evaluation shall be completed based on the following:
(i) Wetland Reconnaissance. This type of wetland assessment does not require flagging of wetland boundaries or completing a wetland rating form. It shall be used if no regulated wetland is present within 300 feet of the project area, which includes those areas that may be temporarily affected by construction-related activities or would be within the limits of construction. The wetland reconnaissance requires the wetland specialist to assess all areas within 300 feet of any proposed project component.
(ii) Wetland Delineation. This type of wetland assessment shall be used if any portion of the proposed project is within 300 feet of a regulated wetland, including those areas that may be temporarily affected by construction-related activities or are within the proposed limits of clearing. The on-site wetland boundary shall be flagged in the field and flags shall be numbered sequentially, and a wetland rating form shall be completed, as required by subsection
(2) of this section, for each wetland identified. A wetland delineation report shall be prepared by the wetland specialist based on report requirements presented in Article IX (Special Reports) of this chapter.
(b) If the wetland is located off of the property involved in the project application and is inaccessible, the best available information shall be used to determine the wetland boundary and category.
(Ord. 5-20 § 2 (Appx. A))