16.18C.040 Performance standards – Specific habitats.
A. Habitat for Endangered, Threatened, and Sensitive Species.
1. No development shall be allowed within a fish and wildlife habitat conservation area or buffer with which state or federally endangered, threatened, or sensitive species have a primary association, except that which is provided for by a management plan established by the Washington Department of Fish and Wildlife or applicable state or federal agency.
2. Whenever activities are proposed adjacent to a fish and wildlife habitat conservation area with which state or federally endangered, threatened, or sensitive species have a primary association, such area shall be protected through the application of protection measures in accordance with a critical area report prepared by a qualified professional and approved by the city. Approval for alteration of land adjacent to a fish and wildlife habitat conservation area or its buffer shall not occur prior to consultation with the Washington Department of Fish and Wildlife for animal species, the Washington State Department of Natural Resources for plant species, and other appropriate federal or state agencies, such as the National Marine Fisheries Service for listed fish species.
3. Bald eagle habitat shall be protected pursuant to the Washington State Bald Eagle Protection Rules (WAC 232-12-292). Whenever activities are proposed adjacent to a verified nest territory or communal roost, a habitat management plan shall be developed by a qualified wildlife professional. Activities are defined as adjacent to bald eagle sites when they are within eight hundred feet of a site or within one-half mile (two thousand six hundred forty feet) and in a shoreline foraging area. The city shall verify the location of eagle management areas for each proposed activity. Approval of the activity shall not occur prior to approval of the habitat management plan by the Washington Department of Fish and Wildlife.
B. Salmonid Fish Habitat.
1. All activities, uses, and alterations proposed to be located in water bodies used by salmonid fish or in areas that affect such water bodies shall give special consideration to the preservation and enhancement of salmonid fish habitat, including, but not limited to, adhering to the following standards:
a. Activities shall be timed to occur only during the allowable work window as designated by the Washington Department of Fish and Wildlife for the applicable species;
b. Alternative alignment or location for the activity shall be considered and if determined not to be feasible, this determination shall be documented for review by the city;
c. The activity is designed so that it will not degrade the functions or values of the fish habitat or other critical areas;
d. Any impacts to the functions or values of the fish and wildlife habitat conservation area are mitigated in accordance with an approved critical area report.
2. Structures that prevent the migration of salmonids shall not be allowed in any portion of water bodies currently or historically used by salmonid fish. Fish bypass facilities shall be provided that allow the upstream migration of adult fish and shall prevent fry and juveniles migrating downstream from being trapped or harmed.
3. Fills shall not adversely impact salmonid fish or their habitat or shall mitigate any unavoidable impacts and shall only be allowed for a water-dependent use.
C. Wetland Habitats. All proposed activities within or adjacent to fish and wildlife habitat conservation areas containing wetlands shall conform to the wetland development performance standards set forth in wetlands (Chapter 16.18B). If nonwetlands habitat and wetlands are present at the same location, the provisions of this chapter or the wetlands chapter, whichever provides greater protection to the habitat, apply.
D. Riparian Habitat Areas. Unless otherwise allowed in this chapter, all structures and activities shall be located outside of a riparian habitat area.
1. Establishment of Riparian Habitat Areas. Riparian habitat areas shall be established for habitats that include aquatic and terrestrial ecosystems that mutually benefit each other and that are located adjacent to rivers, perennial or intermittent streams, seeps, and springs.
|
Water Type (1) |
Width of Riparian Habitat Area |
|---|---|
|
Types 1 and 2; or shorelines of the state, or shorelines of statewide significance |
250 feet |
|
Type 3; or other perennial or fish bearing water, 5 – 20 feet wide |
200 feet |
|
Type 3; or other perennial or fish bearing streams <5 feet wide |
50 feet |
|
Types 4 and 5; or intermittent streams and washes with low mass wasting potential1 |
150 feet |
|
Types 4 and 5; or intermittent streams and washes with high mass wasting potential2 |
225 feet |
1Mass wasting is a general term for a variety of processes by which large masses of rock or earth material are moved down slope by gravity, either slowly or quickly.
2See previous footnote.
2. Riparian Habitat Area Widths. Riparian habitat area widths are shown in the table above. A riparian habitat area shall have the width indicated, unless a greater width is required pursuant to subsection (D)(3) of this section or because of a different, overlapping critical area buffer, or a lesser width is allowed pursuant to subsection (D)(4) of this section. Widths shall be measured outward in each direction, on the horizontal plane, from the ordinary high water mark, or from the top of bank, if the ordinary high water mark cannot be identified. Riparian habitat areas should be sufficiently wide to achieve the full range of riparian and aquatic ecosystem functions, which include but are not limited to protection of instream fish habitat through control of temperature and sedimentation in streams; preservation of fish and wildlife habitat; and connection of riparian wildlife habitat to other habitats.
3. Increased Riparian Habitat Area Widths. The recommended riparian habitat area widths shall be increased, as follows:
a. When the mayor or designee determines that the recommended width is insufficient to prevent habitat degradation and to protect the structure and functions of the habitat area;
b. When a channel migration zone is present, the riparian habitat area width shall be measured from the outer edge of the channel migration zone;
c. When the riparian habitat area is in an area of high blowdown potential, the riparian habitat area width shall be expanded an additional fifty feet on the windward side;
d. When the riparian habitat area is within an erosion or landslide hazard area, or buffer, the riparian habitat area width shall be the recommended distance, or the erosion or landslide hazard area or buffer, whichever is greater; or
e. When the riparian habitat area is within, overlaps with, or is adjacent to a wetland, or its buffer, the riparian habitat area width shall be the recommended distance, or wetland or buffer width, whichever is greater.
4. Riparian Habitat Area Width Averaging. The mayor or designee may allow the recommended riparian habitat area width to be reduced in accordance with a critical area report only if:
a. The width reduction will not reduce stream or habitat functions, including those of non-fish habitat;
b. The width reduction will not degrade the habitat, including habitat for salmonid fish;
c. The proposal will provide additional habitat protection;
d. The total area contained in the riparian habitat area of each stream on the development proposal site is not decreased;
e. The recommended riparian habitat area width is not reduced by more than twenty-five percent in any one location;
f. The width reduction will not be located within another critical area or associated buffer; and
g. The reduced riparian habitat area width is supported by the best available science.
5. Riparian Habitat Mitigation. Mitigation of adverse impacts to riparian habitat areas shall result in equivalent functions and values on a per function basis, be located as near the alteration as feasible, and be located in the same subdrainage basin as the habitat impacted.
6. Alternative Mitigation for Riparian Habitat Areas. The performance standards set forth in this subsection may be modified at the city’s discretion if the applicant demonstrates that greater habitat functions, on a per function basis, can be obtained in the affected sub-drainage basin as a result of alternative mitigation measures.
E. Aquatic Habitat. The following specific activities may be permitted within a riparian habitat area, pond, lake, water of the state, watercourse, or associated buffer when the activity complies with all of the standards of this chapter. The standards that provide the most protection to protected habitat and species shall apply.
1. Clearing and Grading. When clearing and grading is permitted as part of an authorized activity or as otherwise allowed in these standards, the following shall apply:
a. Grading is allowed only during the dry season, which is typically regarded as beginning on May 1st and ending on October 1st of each year; provided, that the city may extend or shorten the dry season on a case-by-case basis, determined based on actual weather conditions.
b. Filling or modifying a wetland or wetland buffer is permitted only if it is conducted as part of an approved wetland alteration.
c. The soil duff layer shall remain undisturbed to the maximum extent possible. Where feasible, any soil disturbed shall be redistributed to other areas of the site, unless doing so would result in additional impacts to critical areas or high quality uplands that would otherwise remain undisturbed.
d. The moisture-holding capacity of the topsoil layer shall be maintained by minimizing soil compaction or reestablishing natural soil structure and infiltrative capacity on all areas of the project area not covered by impervious surfaces.
e. Erosion and sediment control that meets or exceeds the standards set forth in Chapter 13.46 shall be provided.
2. Streambank Stabilization. Streambank stabilization to protect new structures from future channel migration is not permitted except when such stabilization is achieved through bioengineering or soft armoring techniques in accordance with an approved critical area report.
3. Roads, Trails, Bridges, and Rights-of-Way. Construction of trails, roadways, and minor road bridging, less than or equal to thirty feet wide, may be permitted in accordance with an approved critical area report subject to the following standards:
a. There is no other feasible alternative route with less impact on the environment;
b. The crossing minimizes interruption of downstream movement of wood and gravel;
c. Roads in riparian habitat areas or their buffers shall not run parallel to the watercourse;
d. Trails shall be located on the outer edge of the riparian area or buffer, except for limited viewing platforms and crossings;
e. Crossings, where necessary, shall only occur as near to perpendicular with the water course as possible and shall cross at the shortest distance feasible across the water body;
f. Mitigation for impacts is provided pursuant to a mitigation plan of an approved critical area report;
g. Road bridges are designed according to the Washington Department of Fish and Wildlife 2013 Water Crossing Design Guidelines, and the Northwest Region National Marine Fisheries Service 2008 Anadromous Salmonid Passage Facility Design; and
h. Trails and associated viewing platforms shall not be made of continuous impervious materials.
4. Utility Facilities. New utility lines and facilities may be permitted to cross watercourses in accordance with an approved critical area report, if they comply with the following standards:
a. Fish and wildlife habitat areas shall be avoided to the maximum extent possible;
b. Installation shall be accomplished by boring beneath the scour depth and hyporheic zone of the water body and channel migration zone, where feasible;
c. The utilities shall cross at an angle greater than sixty degrees to the centerline of the channel in streams or perpendicular to the channel centerline whenever boring under the channel is not feasible;
d. Crossings shall be contained within the footprint of an existing road or utility crossing where possible;
e. The utility route shall avoid paralleling the stream or following a down-valley course near the channel; and
f. The utility installation shall not increase or decrease the natural rate of channel migration.
5. Public Flood Protection Measures. New public flood protection measures and expansion of existing ones may be permitted, subject to the city’s review and approval of a critical area report and the approval of a federal biological assessment by the federal agency responsible for reviewing actions related to a federally listed species.
6. Instream Structures. Instream structures, such as, but not limited to, high flow bypasses, sediment ponds, instream ponds, retention and detention facilities, tide gates, dams, and weirs, shall be allowed only as part of an approved watershed basin restoration project approved by the city and upon acquisition of any required state or federal permits. The structure shall be designed to avoid modifying flows and water quality in ways that may adversely affect fish and wildlife habitat conservation areas and shall be designed so as to not block or impede fish passage for any life history stage.
7. Stormwater Conveyance Facilities. Conveyance structures may be permitted in accordance with an approved critical area report subject to the following standards:
a. No other feasible alternatives with less impact exist;
b. Mitigation for impacts is provided;
c. Stormwater conveyance facilities shall incorporate fish habitat features; and
d. Vegetation shall be maintained and, if necessary, added adjacent to all open channels and ponds in order to retard erosion, filter out sediments, and shade the water.
8. On-Site Sewage Systems and Wells.
a. New on-site sewage systems and individual wells may be permitted in accordance with an approved critical area report only if accessory to an approved residential structure, for which it is not feasible to connect to a public sanitary sewer system.
b. Repairs to failing on-site sewage systems associated with an existing structure shall be accomplished by utilizing one of the following methods that result in the least impact:
i. Connection to an available public sanitary sewer system;
ii. Replacement with a new on-site sewage system located in a portion of the site that has already been disturbed by development and is located landward as far as possible, provided the proposed sewage system is in compliance with the King County health department; or
iii. Repair to the existing on-site septic system. (Ord. 1104-15 § 1 (Att. A)).