16.50.250 Designating, Rating, and Mapping Wetlands.
(1) Designating Wetlands. Identification of wetlands and delineation of their boundaries pursuant to this Chapter shall be determined by a qualified professional in accordance with the most current approved federal wetland delineation manual and applicable regional supplements. All areas within the city meeting the wetland designation criteria in that procedure are hereby designated critical areas, regardless of any formal identification, and are subject to the provisions of this Chapter, with the exception of areas under the jurisdiction of the city’s Shoreline Master Program, codified as Chapter 16.55.
(2) Wetland Ratings. Wetlands shall be rated according to the Department of Ecology wetland rating system found in the Washington State Wetland Rating System for Eastern Washington (Department of Ecology Publication #14-06-030, or as amended and approved by the Department of Ecology). This document contains definitions and methods for determining if the general criteria below are met.
(a) Wetland Rating Categories.
(i) Category I wetlands are: 1) alkali wetlands; 2) wetlands with high conservation value that are identified by scientists of the Washington Natural Heritage Program/Department of Natural Resources; 3) bogs and calcareous fens; 4) mature and old-growth forested wetlands over one-quarter acre with slow-growing trees; 5) forests with stands of aspen; and 6) wetlands that perform many functions very well (scores between 22-27 points). These wetlands are those that 1) present a unique or rare wetland type; or 2) are more sensitive to disturbance than most wetlands; or 3) are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or 4) provide a high level of function.
(ii) Category II wetlands are: 1) forested wetlands in the floodplains of rivers; 2) mature and old-growth forested wetlands over one-quarter acre with fast-growing trees; 3) vernal pools; and 4) wetlands that perform functions well (scores between 19-21 points). These wetlands are difficult, though not impossible, to replace, and provide high levels of some functions. These wetlands occur more commonly than Category I wetlands, but still need a relatively high level of protection.
(iii) Category III wetlands are wetlands with a moderate level of functions (scores between 16-18 points). Wetlands scoring between 16-18 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.
(iv) Category IV wetlands have the lowest level of functions (scores fewer than 16 points) and are often heavily disturbed. These are wetlands should be able to be replaced, and in some cases be able to be improved. However, experience has shown that replacement cannot be guaranteed in any specific case. These wetlands may provide some important functions and also need to be protected.
(b) Date of Wetland Rating. Wetland rating categories shall be applied as the wetland exists on the date of adoption of the rating system by the local government, as the wetland naturally changes thereafter, or as the wetland changes in accordance with permitted activities. Wetland rating categories shall not change due to illegal modifications.
(3) Mapping. The approximate location and extent of known wetlands are shown on the pertinent city critical area map. National Wetland Inventory Maps and the city critical area map regarding wetlands are to be used as a guide for the city, project applicants, and property owners, and will be periodically updated as new information becomes available. These maps are a reference and do not provide a final critical area designation. The exact location of a wetland’s boundary shall be determined through the performance of a field investigation by a qualified professional applying the delineation methods described in this Section. Wetland boundaries shall be clearly demarcated with non-degradable survey flagging labeled “WETLAND BOUNDARY” or “WETLAND DELINEATION.” Flagging shall be attached to existing vegetation or stakes at a maximum interval of 50 linear feet. Individual flags should be labeled with a wetland identifier and consecutive numbers (e.g., A-1 through A-8). (Ord. 19-6 §12, 2019; Ord. 07-27 §5, 2007; Ord. 03-18 §26, 2003).