(1) Freshwater wetland environments and portions thereof, are classified into 4 types based on the identification system set forth below.

(a) Category I wetlands. The following types of wetlands are classed as category I wetlands:

(i) Documented habitat for threatened or endangered plant, animal, or fish species recognized by federal or state agencies; or

(ii) Documented Natural Heritage wetland sites or high quality native wetland communities which qualify as Natural Heritage wetland sites; or

(iii) Documented habitat of regional (Pacific Coast) or national significance for migratory birds; or

(iv) Regionally rare wetland communities; or

(v) Wetlands with irreplaceable ecological functions; or

(vi) Documented wetlands of local significance.

(b) Category II wetlands. The following types of wetlands are classed as category II wetlands:

(i) Documented habitat recognized by federal and state agencies for sensitive plant, animal, or fish species; or

(ii) Documented priority habitats and species recognized by state agencies; or

(iii) Wetlands with significant functions which may not be adequately replicated through creation or restoration; or

(iv) Wetlands with significant habitat value; or

(v) Documented wetlands of local significance.

(c) Category III wetlands. The following types of wetlands are classed as category III when they satisfy no category I, II, or IV criteria.

(d) Category IV wetlands. The following types of wetlands are classed as category IV wetlands:

(i) Wetlands less than one acre in size and hydrologically isolated and comprised of one vegetated class that is dominated (more than eighty percent areal cover) by one species from the list in Table 21; or

(ii) Wetlands less than two acres and hydrologically isolated with one vegetative class and more than ninety percent of the areal cover is any combination of species from the list in Table 22.

(2) Freshwater wetland environment vulnerability score (WVS). The vulnerability of freshwater wetland environments is based on the stream typing system established in WAC 222-16-030 incorporated by reference. The rating of the freshwater wetland environment vulnerability ranges from 1 to 5, where 5 represents the most sensitive category and 1 represents the least sensitive category as follows:

Table 23. Freshwater Wetlands Vulnerability Score (WVS).