(1) For purposes of this chapter, freshwater streams, rivers, lakes, and portions thereof, are classified into 5 water types based on the identification system set forth in WAC 222-16-030 which is incorporated by reference.

(a) "Type 1 Water" means all waters, within their ordinary high-water mark, as inventoried as "shorelines of the state" under chapter 90.58 RCW.

(b) "Type 2 Water" shall mean segments of natural waters which are not classified as Type 1 Water and have a high use and are important from a water quality standpoint for:

(i) Domestic water supplies;

(ii) Public recreation;

(iii) Fish spawning, rearing, or migration or wildlife uses; or

(iv) Are highly significant to protect water quality.

(c) "Type 3 Water" shall mean segments of natural waters which are not classified as Type 1 or 2 Water and have a moderate to slight use and are moderately important from a water quality standpoint for:

(i) Domestic water supplies;

(ii) Public recreation;

(iii) Fish spawning, rearing, or migration or wildlife uses; or

(iv) Are highly significant to protect water quality.

(d) "Type 4 Water" shall mean segments of natural waters which are not classified as Type 1, 2, or 3. Their significance lies in their influence of water quality downstream in Type 1, 2, or 3 Waters. These may be perennial or intermittent.

(e) "Type 5 Water" means all other waters, in natural water courses, including streams with or without a well-defined channel, areas of perennial or intermittent seepage, ponds, and natural sinks. Drainage ways having short periods of runoff are considered to be Type 5 Waters.

(3) The vulnerability of freshwater environments is based on the stream typing system established in WAC 222-16-030 incorporated by reference. The rating of biological and recreational resources ranges from 1 to 5 where 5 represents the most sensitive category and 1 represents the least sensitive category as follows:

TABLE 11.

Freshwater Vulnerability Score (FVS).