(a) Category I. Category I wetlands are: (i) alkali wetlands; (ii) wetlands of high conservation value that are identified by scientists of the Washington Natural Heritage Program/DNR; (iii) bogs and calcareous fens; (iv) mature and old-growth forested wetlands over one-quarter acre with slow-growing trees; (v) forests with stands of aspen; and (vi) wetlands that perform many functions very well (scores between 22 to 27). These wetlands are those that (A) represent a unique or rare wetland type; (B) are more sensitive to disturbance than most wetlands; (C) are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or (D) provide a high level of function.

(b) Category II. Category II wetlands are: (i) forested wetlands in the floodplains of rivers; (ii) mature and old-growth forested wetlands over one-quarter acre with fast-growing trees; (iii) vernal pools; and (iv) wetlands that perform functions well (scores between 19 to 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.

(c) Category III. Category III wetlands have a moderate level of functions (scores between 16 to 18 points). These wetlands can be often adequately replaced with a well-planned mitigation project. Wetlands scoring between 16 to 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.

(d) Category IV. Category IV wetlands have the lowest level of functions (scores fewer than 16 points) and are often heavily disturbed. These are wetlands that we should be able to replace, and in some cases be able to improve. 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.

(a) A larger buffer is necessary to maintain viable populations of existing species; or

(b) The wetlands are used by species proposed or listed by the federal government or the state as endangered, threatened, rare, sensitive or being monitored as habitat for those species or has unusual nesting or resting sites; or

(c) The adjacent land is susceptible to severe erosion and erosion control measures will not effectively prevent adverse wetland impacts; or

(d) The adjacent land has minimal vegetative cover or slopes greater than 25 percent.

(a) The technical study (referenced GMC 26.02.040) provides a sound rationale for a reduced buffer; and

(b) The existing buffer area is well-vegetated with native species and has less than 10 percent slopes; and

(c) No direct or indirect, short-term or long-term adverse impact to the wetland will result from the proposed activity.

(a) The wetland is classified as a Category IV or a Category III wetland with a habitat score of three to four points; and

(b) There will be “no net loss” of functions and values of the wetland; and

(c) The wetland does not contain a breeding population of any native amphibian species, and Wetland Guidance for CAO Updates Eastern Washington Version, page 26; and

(d) The hydrologic functions of the wetland can be improved as outlined in questions 3, 4, 5 of Chart 4 and questions 2, 3, 4 of Chart 5 in the “Guide for Selecting Mitigation Sites Using a Watershed Approach,” (available here: https://ecology.wa.gov/Water-Shorelines/Wetlands/Mitigation); or the wetland is part of a priority restoration plan that achieves restoration goals identified in a shoreline master program or other local or regional watershed plan; and

(e) The wetland lies in the natural routing of the runoff, and the discharge follows the natural routing; and

(f) All regulations regarding storm water and wetland management are followed, including but not limited to local and state wetland and storm water codes, manuals, and permits; and

(g) Modifications that alter the structure of a wetland or its soils will require permits. Existing functions and values that are lost would have to be compensated/replaced.