Chapter 14.06
WETLAND CRITICAL AREAS

Sections:

14.06.010    Purpose.

14.06.020    Designation.

14.06.030    Buffers.

14.06.040    General performance standards.

14.06.050    Permitted alterations.

14.06.060    Critical area report/study.

14.06.070    Wetland mitigation requirements.

14.06.080    Fee-in-lieu mitigation.

14.06.090    Wetland mitigation bank.

14.06.010 Purpose.

The purpose of the wetland critical areas provisions is to protect existing wetlands and maintain no net loss of their functions and val­ues. (Ord. 1243 Exh. B (part), 2006).

14.06.020 Designation.

Wetland areas identified by the city of North Bend and King County are shown on Figure 1, Wetland Area Map1. The map may be periodically revised by the city to add or remove areas based on additional information. Determination of wetland ratings will be based on the entire extent of wetlands, unrelated to property lines or ownership patterns. For the purpose of categorization, wetlands shall be designated according to the Washington State Wetland Rating System for Western Washing­ton (Ecology Publication No. 04-06-025) or as revised: Wetlands shall be designated as fol­lows:

A. Category I are those wetlands that meet any of the following criteria:

1. Wetlands that score 70 or more points (out of 100) in the Washington State Wetland Ratings System for Western Wash­ington; or

2. Bogs larger than one-half acre; or

3. Mature and old-growth forested wetlands larger than one acre.

B. Category II are those wetlands that meet any of the following criteria:

1. Wetlands that score between 51 and 69 points in the Washington State Wetland Ratings System for Western Washington; or

2. A wetland identified by the State Department of Natural Resources as contain­ing “sensitive” plant species; or

3. A bog between one-quarter and one-half acre in size.

C. Category III are those wetlands that score between 30 and 50 points in the Wash­ington State Wetland Ratings System for Western Washington.

D. Category IV are those wetlands that score less than 30 points in the Washington State Wetland Ratings System for Western Washington. (Ord. 1243 Exh. B (part), 2006).

14.06.030 Buffers.

The standard buffer widths presume the existence of a relatively intact native vegeta­tion community in the buffer zone adequate to protect the wetland functions and values at the time of the proposed activity. If the vegetation is inadequate, then the buffer width shall be increased or the buffer should be enhanced by planting or other means to maintain the stan­dard functions and values for the required width. Required standard wetland buffers, based on wetland category and land use inten­sity, are as follows:

A. Category I: 200 feet.

B. Category II.

1.  Adjacent to high intensity uses: 100 feet.

2. Adjacent to low intensity uses: 75 feet.

C. Category III.

1. Adjacent to high intensity uses: 75 feet.

2. Adjacent to low intensity uses: 50 feet.

D. Category IV.

1. Adjacent to high intensity uses: 50 feet.

2. Adjacent to low intensity uses: 35 feet.

E. Any wetland created as compensation for an approved wetland alteration shall have the standard buffer required for the new classi­fication of the created wetland. Wetlands to be created shall be located such that the new asso­ciated wetland buffer does not cross onto adja­cent property, unless the same property owner owns the adjacent property or secures an NGPE for the buffer on the adjoining property.

F. Wetlands shall be assigned a rating based on the wetland report and field verifica­tion, and the appropriate buffer shall apply. (Ord. 1243 Exh. B (part), 2006).

14.06.040 General performance standards.

The requirements provided in this section supplement those identified in Chapter 14.05 NBMC. Activities and uses shall be prohibited from wetlands and wetland buffers, except as provided by this chapter. (Ord. 1243 Exh. B (part), 2006).

14.06.050 Permitted alterations.

The following activities may only be per­mitted in a wetland or wetland buffer if the applicant can demonstrate that the activity will not degrade the functions and values of the wetland and other critical areas. The director may require the preparation of a critical area report to confirm compliance with the require­ments of this chapter.

A. Conservation or preservation activities that improve the function of the existing wet­land.

B. Modifications to existing structures where no further alteration or increase in foot­print will occur.

C. Trails. Public and private trails may be allowed within wetland buffers where it can be demonstrated in a critical area report that the wetland and wetland buffer functions and val­ues will not be degraded by trail construction or use. Trail planning, construction, and main­tenance shall adhere to the following criteria:

1. Permeable surface trail alignment shall be located only in the outer 50 percent of a wetland buffer width, except as needed to access viewing platforms or to cross the wet­land. Trails may be placed on existing levees, railroad grades, or road grades within these limits;

2. Trails and associated viewing plat­forms shall be constructed of pervious materials, unless impervious surfaces are necessary for conformance to the Americans with Disabilities Act. The trail surface shall meet all other requirements, including water quality standards set forth in the King County Surface Water Design Manual, 1998, or as revised;

3. Trail alignment shall avoid trees in excess of six inches in diameter of any tree trunk at a height of four and one-half feet above the ground on the upslope side of the tree, where feasible;

4. Trail construction and maintenance shall follow the U.S. Forest Service Trails Man­agement Handbook (FSH 2309.18, June 1987) and Standard Specifications for Construction of Trails (EM-7720-102, June 1984, or as revised);

5. Access trails to viewing platforms within the wetland may be provided. Trail access and platforms shall be aligned and con­structed to minimize disturbance to valuable functions of the wetland or its buffer and other habitat elements, and still provide enjoyment of the resource; and

6. Buffer widths shall be increased, where possible, equal to the width of the trail corridor, including disturbed areas.

D. Stormwater Management Facilities. All wetland categories may receive clean runoff from sources such as roof drains and footing drains when such runoff is demonstrated as ben­eficial to wetland functions. Stormwater man­agement facilities are not allowed in Category I and II wetlands and buffers. The outer 50 feet of Category III and all portions of Category IV wetland buffers may be used for detention/reten­tion areas where the applicant can demonstrate no practical alternative and that such use is ben­eficial to wetland functions. Enhanced treatment is required prior to discharge to such wetlands, and a stormwater facility maintenance plan shall be submitted.

E. Public Roads and Utilities. Footprint expansion of public roads and utilities may occur to maintain locally established levels of service, and to provide for and protect public safety when no lesser impacting option is feasi­ble, and the width of the corridor is minimized to the maximum extent possible. Public and pri­vate utility corridors may be allowed within wetland buffers for Category II, III, and IV wet­lands when no lesser impacting alternative alignment is feasible, and wetland buffer func­tions and values will not be degraded. Utilities, whenever possible, shall be constructed in exist­ing, improved roads, drivable surface or shoul­der, subject to compliance with road maintenance BMPs, or within an existing utility corridor. Otherwise, corridor alignment, con­struction, restoration, and maintenance shall adhere to the following criteria:

1. Corridor alignment shall follow a path beyond a distance from the wetland edge equal to 75 percent of the buffer width, except when crossing a Category IV wetland and its buffer;

2. Corridor construction and mainte­nance shall maintain and protect the hydrologic and hydraulic functions of the wetland and the buffer;

3. Corridors shall be fully revegetated with appropriate native vegetation upon com­pletion of construction; and

4. Utilities requiring maintenance roads shall be prohibited in wetland buffers unless the following criteria are met:

a. There are no lesser impacting alternatives;

b. Any required maintenance roads shall be no greater than 15 feet wide. Roads shall closely approximate the location of the utility to minimize disturbances; and

c. The maintenance road shall be constructed of pervious materials and designed to maintain and protect the hydrologic functions of the wetland and its buffer.

F. Category IV Wetlands. Allowable uses and activities shall include all uses and activities identified in subsections A through E of this sec­tion. In addition, activities and uses that result in unavoidable and necessary impacts may be per­mitted in Category IV wetlands and associated buffers in accordance with an approved critical area report and mitigation plan, and only if the proposed activity is the only reasonable alterna­tive that will accomplish the applicant’s objec­tive. (Ord. 1243 Exh. B (part), 2006).

14.06.060 Critical area report/study.

Wetland delineation/classification survey teams shall include qualified wildlife profes­sionals when the area in question is identified by the city of North Bend as being a potential or known fish and wildlife habitat area. Such wildlife surveys shall be undertaken during suitable times of the year for the documenta­tion of seasonal wildlife occurrences and criti­cal life history stages. In addition to the general requirements for critical area reports provided under Chapter 14.05 NBMC, wet­land critical area reports shall include the fol­lowing:

A. On the site map:

1. The edge of the wetland as flagged and surveyed in the field using the Washington State Wetland Identification and Delineation Manual, as required by RCW 36.70A.157;

2. The location of any proposed wet­land area(s) to be created through mitigation measures; and

3. The location of any proposed wet­land alteration or fill.

B. In the report:

1. Description of the wetland by clas­sification per the Washington State Wetland Rating System for Western Washington (Ecol­ogy Publication No. 04-06-025 or as revised);

2. General condition of wetland;

3. Description of vegetation species and community types present in the wetland and surrounding buffer;

4. List of priority species and habitats within the vicinity of the wetland in question;

5. Description of soil types within the wetland and the surrounding buffer using the USDA Soil Conservation Service soil classifi­cation system; and

6. Description of hydrologic regime and findings. (Ord. 1243 Exh. B (part), 2006).

14.06.070 Wetland mitigation requirements.

No net loss of wetland functions and val­ues shall occur as a result of the overall project. If a wetland alteration is allowed, then the associated impacts will be considered unavoidable. In addition to the requirements in Chapter 14.05 NBMC, the following mitiga­tion measures to minimize and reduce wetland impacts shall be required:

A. Mitigation shall achieve equivalent or greater biological functions. Mitigation plans shall be consistent with the State Department of Ecology Guidelines for Developing Fresh­water Wetland Mitigation Plans and Propos­als, 1994, or as revised. If Class 4 wetlands are not in or adjoining a designated wildlife habi­tat area, greater biological functions and val­ues may be achieved by mitigating impacts off-site. See NBMC 14.05.155(C)(6) for enhancement as mitigation options.

B. Preference of Mitigation Actions. Mit­igation actions that require compensation shall occur in the following order of preference:

1. Restoring wetlands on upland sites that were formerly wetlands, except that the preferred location for Class IV mitigation shall be off-site in or adjoining a designated wildlife habitat area. The off-site mitigation ratio for Category IV wetlands shall be 1:1 when appli­cants choose to mitigate in or adjacent to fish and wildlife habitat areas.

2. Creating wetlands on disturbed upland sites such as those with vegetation cover consisting primarily of nonnative intro­duced species. This should only be attempted when there is a consistent source of hydrology and it can be shown that the surface and sub­surface hydrologic regime is conducive for the wetland community that is designed.

3. Enhancing significantly degraded wetlands only after a minimum 1:1 replace­ment ratio has been met.

C. On-Site and Off-Site Mitigation. Unless otherwise approved, all wetland impacts shall be compensated for through res­toration or creation of replacement wetlands that are in-kind, on-site or off-site, and of sim­ilar or better wetland category. Mitigation shall be timed prior to or concurrent with the approved alteration and shall have a high prob­ability of success. The following ratios shall apply to wetland restoration and creation for mitigation:

1. Category I on a 6:1 area basis with equal or greater functions and values.

2. Category II on a 3:1 area basis with equal or greater functions and values.

3. Category III on a 2:1 area basis with equal or greater functions and values.

4. Category IV on a 1.5:1 area basis with equal or greater functions and values.

D. Exemption from Mitigation. Category IV wetlands less than 1,000 square feet shall be exempt from critical area regulations where it has been shown by the applicant that the fol­lowing conditions have been met:

1. Wetland is not associated with a riparian corridor;

2. Wetland is not associated with other wetlands; and

3. Wetlands do not contain habitat identified as essential for local populations of priority species identified by the Washington State Department of Fish and Wildlife.

E. Exemption for Avoidance. The require­ment to avoid impacts, specifically including the following exceptions, public agency/util­ity, reasonable use, variance, farm plan, or master plan, may be dropped for Category III and IV wetlands less than 4,356 square feet that meet all of the following criteria:

1. Wetland is not associated with a riparian corridor;

2. Wetland is not associated with other wetlands; and

3. Wetlands do not contain habitat identified as essential for local populations of priority species identified by the Washington State Department of Fish and Wildlife. (Ord. 1243 Exh. B (part), 2006).

14.06.080 Fee-in-lieu mitigation.

For Category IV isolated wetlands of 4,356 square feet or less, mitigation may be accom­plished by compensating for wetland loss through a fee-in-lieu based on a 1:1 ratio. In addition to critical areas approval for fill of these wetlands, the applicant must demon­strate compliance with the city’s shoreline reg­ulations, the Department of Ecology, and where applicable, the Corps of Engineers (CORPS). The applicant must obtain a juris­dictional determination from the agencies and show proof of permit approval, if applicable. Fee-in-lieu shall be based on the cost to replace the wetland at an off-site location in or adjoin­ing a designated wildlife habitat area, includ­ing land costs, wetland construction, and monitoring.

Where the Corps has jurisdiction over wet­lands, Ecology issues a Section 401 Water Quality Certification and the Corps issues a permit for wetland fill (33 CFR Parts 320 through 330) under Section 404 of the federal Clean Water Act. Nationwide permits under Section 404 generally authorize fill of one-half acre or less in nontidal wetlands that are not adjacent to streams where average annual flow is five cubic feet or more per second. The Corps requires individual permits for larger impacts and for all wetlands in floodplains or adjacent to larger streams and rivers. The Corps normally does not have jurisdiction over hydrologically isolated wetlands and prior converted croplands that otherwise meet wet­land criteria. Under the State Water Pollution Control Act (Chapter 90.48 RCW), the Wash­ington State Department of Ecology (Ecology) has authority to regulate impacts to such wet­lands via administrative order. (Ord. 1243 Exh. B (part), 2006).

14.06.090 Wetland mitigation bank.

The city of North Bend encourages the pursuit of wetland mitigation banking in the upper Snoqualmie Valley. Wetland banking options should not include nonwetland areas of the central meadow open spaces of Mead­owbrook and Tollgate farms, unless otherwise approved by the city council. Feasibility stud­ies should first identify successful sites where wetlands currently exist or could be enhanced through off-site mitigation requirements. (Ord. 1243 Exh. B (part), 2006).

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