B. The standard buffer width will be established unless the applicant can demonstrate one or both of the following:

1. The proposed use and/or activities are considered low impact, and meet the following conditions:

a. The site layout includes no parking, outdoor storage or use of any kind of machinery between building and buffer;

b. Use does not involve usage or storage of chemicals;

c. Passive areas are located adjacent to buffer; and

d. Stream and buffer protections are incorporated into the site design; these may include use of landscaping features, berms, fences, water quality protections and other measures which preserve the character and function of the stream and its buffer.

2. Stream and buffer enhancement is implemented through the review and adoption of an approved buffer enhancement plan (BEP). The buffer enhancement plan should include but is not limited to the following applicable provisions:

a. Removal of fish barriers to restore accessibility to anadromous fish;

b. Enhancement of fish habitat using log structures incorporated as part of a fish habitat enhancement plan;

c. Enhancement of fish and wildlife habitat structures that are likely to be used by fish and wildlife, including wood duck houses, bat boxes, nesting platforms, snags, rootwads/stumps, birdhouses, and/or heron nesting areas;

d. Planting native vegetation within the buffer area, especially vegetation that would increase value for fish and wildlife, increase stream bank or slope stability, improve water quality, or provide aesthetic/recreational value;

e. Create a surface channel where a stream was previously culverted or piped;

f. Remove or modify existing stream culverts (such as at road crossings) to improve fish passage and flow capabilities;

g. Upgrade and enhance retention/detention facilities or other drainage facilities.

C. No structures or improvements shall be permitted within the stream buffer area, including buildings, decks, docks, except under one of the following circumstances:

1. When the improvements are part of an approved rehabilitation or mitigation plan; or

2. For construction of new roads and utilities, and accessory structures, when no feasible alternative location exists; or

3. Construction of trails, according to the following criteria:

a. Constructed of permeable or semi-permeable materials,

b. Designed to minimize impact on the stream system,

c. Of a maximum trail corridor width of five feet (see Section 16.10.030(A)(11)), and

d. Located within the outer half of the buffer, i.e., the portion of the buffer that is farther away from the stream; or

4. Construction of footbridges; or

5. Construction of educational facilities and informational signs; or

6. Stormwater management facilities, such as grass-lined swales, may not be located within the minimum buffer area as set forth in the table in subsection A of this section. Treated stormwater discharge may be permitted consistent with an approved stormwater management plan.

D. The town may extend the width of the buffer on the basis of site-specific analysis when necessary to comply with a basin plan adopted by the town in accordance with county or regional plans to preserve endangered or threatened species.

E. Stream buffer widths may be modified by averaging buffer widths as set forth herein.

1. Buffer width averaging shall be allowed only where the applicant demonstrates to the town that the stream contains variations in sensitivity due to existing physical characteristics, that lower intensity land uses would be located adjacent to areas where buffer width is reduced, and that the total area contained within the buffer after averaging is no less than that contained within the standard buffer prior to averaging. Buffer averaging shall not result in the buffer width being reduced by more than twenty-five percent of the required buffer as set forth in the table in subsection A of this section and in no case may the buffer be less than twenty-five feet in width.

2. A buffer enhancement plan (BEP) may be required, if buffer averaging is proposed.

F. When a development permit is required, a regulated stream and its associated buffer shall be placed either in a separate tract on which development is prohibited, protected by execution of an easement, dedicated to a conservation organization or land trust, or similarly preserved through a permanent protective mechanism acceptable to the town. In this case, the location and limitations associated with the stream and its buffer shall be shown on the face of the deed or plat applicable to the property and shall be recorded with the Snohomish County department of records.

G. When a development permit is required, buffers shall be permanently marked by green metal fence posts in a manner acceptable to the town with one inch by two foot rebar buried beside each post. The number of post/rebar markers shall be sufficient to indicate the boundary of the buffer and the minimum shall be two. The approximate location of the posts based on measurements shall be shown on a site plan which shall be recorded with the Snohomish County department of records. It shall be the responsibility of the property owner to maintain, and if necessary reestablish these permanent markers. (Ord. 00-387 §1(part), 2000)