14.100.540 Fish and Wildlife Habitat Conservation Areas—General Requirements.
A. Alterations. A habitat conservation area may be altered only if the proposed alteration of the habitat or the mitigation proposed does not degrade the quantitative and qualitative functions and values of the habitat. All new structures and land alterations shall be prohibited from habitat conservation areas, except in accordance with this chapter.
B. Nonindigenous Species. No plant, wildlife, or fish species not indigenous to the region shall be introduced into a habitat conservation area unless authorized by a state or federal permit or approval.
C. Mitigation and Contiguous Corridors. Mitigation sites shall be located to preserve or achieve contiguous wildlife habitat corridors in accordance with a mitigation plan that is part of an approved critical area report to minimize the isolating effects of development on habitat areas, so long as mitigation of aquatic habitat is located within the same aquatic ecosystem as the area disturbed.
D. Approvals of Activities. The director shall condition approvals of activities allowed within or adjacent to a habitat conservation area or its buffers, as necessary to minimize or mitigate any potential adverse impacts. Conditions shall be based on the best available science and may include, but are not limited to, the following:
1. Establishment of buffer zones;
2. Preservation of critically important vegetation and/or habitat features such as snags and downed wood;
3. Limitation of access to the habitat area, including fencing to deter unauthorized access;
4. Seasonal restriction of construction activities;
5. Establishment of a duration and timetable for periodic review of mitigation activities; and
6. Requirement of a performance bond, when necessary, to ensure completion and success of proposed mitigation.
E. Mitigation and Equivalent or Greater Biological Functions. Mitigation of alterations to habitat conservation areas shall achieve equivalent or greater biologic and hydrologic functions and shall include mitigation for adverse impacts upstream or downstream of the development proposal site. Mitigation shall address each function affected by the alteration to achieve functional equivalency or improvement on a per function basis.
F. Approvals and the Best Available Science. Any approval of alterations or impacts to a habitat conservation area shall be supported by the best available science.
G. Buffers.
1. Establishment of Buffers. The director shall require the establishment of buffer areas for activities adjacent to habitat conservation areas when needed to protect habitat conservation areas. Buffers shall consist of an undisturbed area of native vegetation or areas identified for restoration established to protect the integrity, functions, and values of the affected habitat. Required buffer widths shall reflect the sensitivity of the habitat and the type and intensity of human activity proposed to be conducted nearby and shall be consistent with the management recommendations issued by the Washington Department of Fish and Wildlife. Habitat conservation areas and their buffers shall be preserved in perpetuity through the use of native growth protection areas and critical area tracts in accordance with Section 14.100.081.
2. Seasonal Restrictions. When a species is more susceptible to adverse impacts during specific periods of the year, seasonal restrictions may apply. Larger buffers may be required and activities may be further restricted during the specified season.
3. In order to maintain effective buffer conditions and functions, a vegetation management plan shall be required for all buffer areas established to include:
a. Maintaining adequate cover of native vegetation including trees and understory; if existing tree cover is less than a relative density of twenty (20), planting shall be required consisting of seedlings at a density of three hundred (300) stems per acre or the equivalent.
b. Provide a dense screen of native evergreen trees at the perimeter of the buffer. If existing vegetation is not sufficient to prevent viewing adjacent development from within the buffer, planting shall be required equivalent to two (2) rows of three (3) foot high stock of native evergreens at a triangular spacing of fifteen (15) feet or three (3) rows of gallon containers at a triangular spacing of eight (8) feet. Fencing may be required if needed to block headlights or other sources of light or to provide an immediate effective visual screen.
c. Provide a plan for control of invasive weeds, and remove existing invasive species.
d. Provide for a monitoring and maintenance plan for a period of at least five (5) years, except this provision may be waived for single-family residential lots.