17.130.050 Classification of streams.
(1) Type 1 Stream. All streams, within their ordinary high-water mark, as inventoried as “shorelines of the state” under Chapter 90.58 RCW and the rules promulgated pursuant to Chapter 90.58 RCW, but not including those waters’ associated wetlands as defined in Chapter 90.58 RCW.
(2) Type 2 Stream. Segments of natural streams that are not classified as Type 1 Streams and have a high fish and wildlife use. These are segments of natural streams and periodically inundated areas of their associated wetlands, which:
(a) Are used by fish for spawning, rearing or migration. Stream segments having a defined channel 20 feet or greater within the average bankfull width and having a gradient of less than four percent are presumed to have highly significant fish populations;
(b) Are used by fish for off-channel habitat. These areas are critical to the maintenance of optimum survival of fish. This habitat shall be identified based on the following criteria:
(i) The site must be connected to a fish-bearing stream and be accessible during some period of the year; and
(ii) The off-channel water must be accessible to fish through a drainage with less than a five percent gradient.
(3) Type 3 Stream. Segments of natural streams that are not classified as Type 1 or 2 Streams and have a moderate to slight fish and wildlife use. These are segments of natural streams and periodically inundated areas of their associated wetlands which are used by fish for spawning, rearing or migration. The requirements for determining fish use are described in the State Forest Practices Board Manual, Section 13. If fish use has not been determined, streams having the following characteristics are presumed to have fish use:
(a) Stream segments having a defined channel of two feet or greater within the average bankfull width, and having a gradient of 16 percent or less; and
(b) Stream segments having a defined channel of two feet or greater within the average bankfull width, a gradient greater than 16 percent and less than or equal to 20 percent, and a contributing basin size based on hydrographic boundaries greater than 50 acres.
(4) Type 4 Stream. All segments of natural streams within the average bankfull width of defined channels that are perennial nonfishhabitat streams. Perennial streams are streams that do not go dry any time during a year of normal rainfall. If the uppermost point of perennial flow cannot be identified with simple, nontechnical observations (see State Forest Practices Board Manual, Section 23), then Type 4 Streams begin at a point along the channel where the contributing basin area is at least 52 acres.
(5) Type 5 Stream. All segments of natural streams within the average bankfull width of the defined channels that are not Type 1, 2, 3, or 4 Streams. These are seasonal, nonfish-habitat streams in which surface flow is not present for at least some portion of the year. (Ord. 1164 § 4, 2004).