20.740.140 Wetlands.
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A. Designating and Rating Wetlands.
1. Designating Wetlands. Wetlands are those areas, designated in accordance with the approved federal wetland delineation manual and applicable regional supplements, that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. Wetlands do not include those artificial wetlands intentionally created (but not as mitigation for impacts to wetlands) from nonwetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds and landscape amenities or those wetlands created after July 1990 that were unintentionally created as a result of the construction of a road, street, or highway. Wetlands shall include those artificial wetlands intentionally created from nonwetland areas to mitigate conversion of wetlands.
Final designations shall be based on site conditions and other available data or information (see VMC 20.740.020(C)(1)).
2. Wetland Ratings. Wetlands shall be rated according to the Washington State Department of Ecology (Ecology) wetland rating system, Washington State Wetland Rating System for Western Washington – 2014 Update, Ecology Publication No. 14-06-029, October 2014, or as revised by Ecology. The rating system document contains the definitions and methods for determining if the criteria below are met. The most recent version of the rating system form must be used.
a. Wetland Rating Categories.
i. Category I. Category I wetlands are:
A. Relatively undisturbed estuarine wetlands larger than one acre;
B. Wetlands of high conservation value that are identified by scientists of the Washington Natural Heritage Program of the Department of Natural Resources;
C. Bogs;
D. Mature and old-growth forested wetlands larger than one acre;
E. Wetlands that perform many functions well, scoring twenty-three points or more. These wetlands are those that:
1. Represent unique or rare wetland types;
2. Are more sensitive to disturbance than most wetlands;
3. Are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or
4. Provide a high level of functions.
ii. Category II. Category II wetlands function at a moderately high function, scoring between twenty and twenty-two points.
iii. Category III. Category III wetlands are:
A. Wetlands with a moderate level of functions, scoring between sixteen and nineteen points; and
B. Can often be adequately replaced with a well planned mitigation project.
iv. Category IV. Category IV wetlands have the lowest levels of functions (scoring fewer than sixteen points) and are often heavily disturbed. These are wetlands that should be able to be replaced, or in some cases improved. However, experience has shown that replacement cannot be guaranteed in any specific case. These wetlands may provide some important functions, and should be protected to some degree.
B. Additional Critical Areas Report Requirements. A critical areas report for wetlands shall be prepared according to the Washington State Wetland Rating System for Western Washington – 2014 Update, Ecology Publication No. 14-06-029, October 2014 or as revised by Ecology. The critical areas report shall contain an analysis of the wetlands including the following site- and proposal-related information:
1. A written assessment, data sheets and accompanying maps of any wetlands or buffers on the site including the following information:
a. Hydrogeomorphic (HGM) subclassification and Cowardin class;
b. Wetland category;
c. Wetland delineation and required buffers;
d. Existing wetland acreage;
e. Vegetative, faunal, and hydrologic characteristics;
f. Soil types and substrate conditions;
g. Topographic elevations, at one-foot contours; and
h. A discussion of the water sources supplying the wetland and documentation of hydrologic regime (locations of inlet and outlet features, water depths throughout the wetland, evidence of recharge or discharge, evidence of water depths throughout the year – drift lines, algal layers, moss lines, and sediment deposits).
2. Functional evaluation for the wetland and buffer using Ecology’s most current approved method and including the reference of the method and all data sheets.
3. Proposed mitigation, if needed, including a discussion of alternatives and trade-offs inherent in the various alternatives (for example, where enhancement for one function would adversely affect another), a written description and accompanying maps of the mitigation area, including the following information:
a. Existing and proposed wetland acreage;
b. Existing and proposed vegetative and faunal conditions;
c. Surface and subsurface hydrological conditions of existing and proposed wetlands and hydrologically associated wetlands including an analysis of existing hydrologic regime and proposed hydrologic regime for enhanced, created, or restored mitigation areas;
d. Relationship to lakes, streams and rivers in the watershed;
e. Soil type and substrate conditions;
f. Topographic elevations, at one-foot contours;
g. Required wetland buffers including existing and proposed vegetation;
h. Identification of the wetland’s contributing area; and
i. A functional assessment of proposed mitigation to ensure no net loss of shoreline ecological function.
C. Performance Standards.
1. General Requirements. Development or clearing activities shall protect the functions of wetlands and wetland buffers on the site. Activities shall result in no net loss of wetland or buffer functions. Protection may be provided by avoiding (the preferred protection) or minimizing and mitigating as described in the general critical areas performance standards (VMC 20.740.060).
a. Wetlands.
i. In Category I wetlands only the following activities may be allowed:
A. A road, railroad, trail, dike, or levee or a water, sewer, stormwater conveyance, gas, power, cable, fiber optic or telephone facility that cannot feasibly be located outside of the wetland, that minimizes the impact, and that mitigates for any unavoidable impact to functions. Cost may be considered, but shall not be overriding; or
B. Trails and wildlife viewing structures; provided, that the trails and structures minimize the impact and are constructed so that they do not interfere with wetland hydrology and do not result in increased sediment entering the wetland.
ii. In Category II wetlands only the following activities may be allowed:
A. Activities allowed in Category I wetlands pursuant to subsection (C)(1)(a)(i) of this section.
B. Enhancement and restoration activities aimed at protecting the soil, water, vegetation or wildlife.
C. Within shoreline jurisdiction (VMC 20.760.020), water-dependent, water-related or water-enjoyment activities where there are no feasible alternatives that would have a less adverse impact on the wetland, its buffers and other critical areas.
D. Where non-water dependent, related or enjoyment activities are proposed, it shall be presumed that alternative locations are available, and activities and uses shall be prohibited unless the applicant demonstrates that the basic project purpose cannot reasonably be accomplished and successfully avoid or result in less adverse impacts on a wetland on another site or sites in the city of Vancouver or Vancouver urban growth area.
iii. In Category III wetlands only the following activities may be allowed:
A. Activities allowed in Category II wetlands pursuant to subsection (C)(1)(a)(ii) of this section.
B. Other activities may be allowed if the applicant demonstrates that the basic project purpose cannot reasonably be accomplished and avoid or result in less adverse impacts on a wetland or its buffer than alternative uses or designs (including reduction in the size, scope, configuration or density of the project).
iv. In Category IV wetlands activities and uses that result in impacts may be permitted in accordance with an approved critical areas report and mitigation plan if the proposed activity is the only reasonable alternative that will accomplish the applicant’s objectives. Full mitigation for the loss of acreage and functions shall be provided under the terms established pursuant to subsection (C)(2) of this section.
b. Wetland Buffers.
i. Standard Buffer Widths. Standard buffer widths are those determined by Ecology and described in Freshwater Wetlands in Washington State, Volume 2: Managing and Protecting Wetlands, Ecology Publication No. 05-06-008, April 2005 or as revised by Ecology. Buffer widths are based on wetland category, wetland characteristics and land use intensity.
A. Land use intensities are as follows:
|
Land Use Intensity |
VMC Title 20 Zoning Districts |
|---|---|
|
High |
All Residential, Commercial or Industrial Zones |
|
Moderate |
Open Space Park or Open Space Greenway: General |
|
Low |
Open Space Greenway: Lettuce Fields or Vancouver Lowlands; or Open Space Natural |
B. Level of function for habitat based on the Washington State Wetland Rating System is as follows:
|
Level of Function |
Habitat Score in Rating System |
|---|---|
|
High |
8 – 9 |
|
Moderate |
6 – 7 |
|
Low |
3 – 5 |
C. Buffer widths are measured horizontally from the edge of the wetland (see VMC 20.170.030(B) and (H)) and are as follows:
1. Category I Wetlands.
|
Wetland Characteristics |
Land Use Intensity |
Buffer Width |
|---|---|---|
|
Wetlands of High Conservation Value |
High Moderate Low |
250’ 190’ 125’ |
|
Forested Wetlands High Habitat Function |
High Moderate Low |
300’ 225’ 150’ |
|
Moderate Habitat Function |
High Moderate Low |
150’ 110’ 75’ |
|
Low Habitat Function |
High Moderate Low |
100’ 75’ 50’ |
|
Other Category I Wetlands High Habitat Function |
High Moderate Low |
300’ 225’ 150’ |
|
Moderate Habitat Function |
High Moderate Low |
150’ 110’ 75’ |
|
Low Habitat Function |
High Moderate Low |
100’ 75’ 50’ |
2. Category II Wetlands.
|
Wetland Characteristics |
Land Use Intensity |
Buffer Width |
|---|---|---|
|
High Habitat Function |
High Moderate Low |
300’ 225’ 150’ |
|
Moderate Habitat Function |
High Moderate Low |
150’ 110’ 75’ |
|
Low Habitat Function |
High Moderate Low |
100’ 75’ 50’ |
3. Category III Wetlands.
|
Wetland Characteristics |
Land Use Intensity |
Buffer Width |
|
Moderate Habitat Function |
High Moderate Low |
150’ 110’ 75’ |
|
Low Habitat Function |
High Moderate Low |
80’ 60’ 40’ |
4. Category IV Wetlands.
|
Wetland Characteristics |
Land Use Intensity |
Buffer Width |
|---|---|---|
|
All Category IV Wetlands |
High Moderate Low |
50’ 40’ 25’ |
D. All buffers shall be measured from the wetland boundary as surveyed in the field.
E. Areas which are completely functionally separated from a wetland and do not protect the wetland from adverse impacts may be excluded from buffers otherwise required.
ii. Wetland Buffer Width Averaging. The shoreline administrator may allow modification of the standard wetland buffer width in accordance with an approved critical areas report on a case-by-case basis by averaging buffer widths. Buffer width averaging shall not be used in combination with buffer width reduction or a minor exception. Averaging of buffer widths (see VMC 20.170.080(B)(2)) may only be allowed where a qualified professional wetland scientist demonstrates that:
A. Such averaging will not reduce wetland functions or functional performance; and
B. The wetland varies in sensitivity due to existing physical characteristics, or the character of the buffer varies in slope, soils, or vegetation, and the wetland would benefit from a wider buffer in places and would not be adversely impacted by a narrower buffer in other places; and
C. The total area contained in the buffer area after averaging is no less than that which would be contained within the standard buffer; and
D. The buffer width is reduced by no more than twenty-five percent of the standard width and at no point to less than twenty-five feet.
iii. Buffer Width Reduction Based on Reducing the Intensity of Impacts from Land Uses. Buffer widths required for high intensity land uses may be reduced to those required for moderate land use intensity under the following conditions:
A. For wetlands with moderate or high habitat function:
1. A relatively undisturbed vegetated corridor at least one hundred feet wide is protected between the wetland and any other priority habitats and areas associated with priority species (VMC 20.740.110(A)(1)(b); and
2. Measures to minimize the impacts of different land uses on wetlands are applied, as approved by the shoreline administrator. Such measures include, but are not limited to, the examples summarized below.
|
Examples of Disturbance |
Uses and Activities that Cause the Disturbance |
Examples of Measures to Minimize Impacts |
|---|---|---|
|
Lights |
Parking lots, warehouses, manufacturing, residential |
Direct lights away from wetland |
|
Noise |
Manufacturing, residential, commercial |
Locate activity that generates noise away from wetland |
|
Toxic runoff |
Parking lots, roads, manufacturing, residential, application of agricultural or landscaping chemicals |
Route only treated runoff to a wetland Establish covenants limiting use of toxic chemicals within 150’ of wetland Apply integrated pest management |
|
Change in water regime |
Impervious surfaces, lawns, tilling |
Infiltrate or treat, detain, and disperse new runoff into buffer |
|
Pets |
Residential |
Plant dense vegetation around buffer, such as rose or hawthorn |
|
Human disturbance |
Residential, commercial, industrial |
Plant dense vegetation around buffer, such as rose or hawthorn |
|
Dust |
Tilled fields |
Utilize best management practices to control dust |
B. For wetlands with low habitat function measures to minimize the impacts of different land uses on wetlands (subsection (C)(1)(b)(iii)(A)(2) of this section) are applied.
C. Buffer width reduction shall not be used in combination with buffer width averaging (subsection (C)(1)(b)(ii) of this section) or a minor exception (VMC 20.740.070).
iv. Buffer Maintenance. Except as otherwise specified or allowed in accordance with this chapter, wetland buffers shall be maintained according to the approved critical areas permit.
v. Buffer Uses. The following uses may be permitted within a wetland buffer in accordance with the review procedures of this chapter; provided, they are not prohibited by any other applicable law or regulation and they are conducted in a manner so as to minimize impacts to the buffer and the wetland:
A. Activities allowed under the same terms and conditions as in the associated wetlands pursuant to subsection (C)(1)(a) of this section, provided trails shall be located in the outer twenty-five percent to fifty percent of the buffer when feasible and consistent with the public access provisions of this program.
B. Enhancement and restoration activities aimed at protecting the soil, water, vegetation or wildlife.
C. Passive recreation facilities including trails and wildlife viewing structures; provided, that the trails and structures are constructed with a surface that does not interfere with wetland hydrology.
D. Stormwater management facilities are not allowed in buffers of Category I or II wetlands. Stormwater management facilities, limited to detention facilities, constructed wetlands, stormwater dispersion outfalls and bioswales, may be constructed in accordance with an approved critical areas report within the buffers of Category III or IV wetlands; provided, that:
1. No other location is feasible; and
2. The location of such facilities will not degrade the functions of the wetland or buffer.
c. Signs and Fencing of Wetlands.
i. The location of the outer perimeter of the wetland and buffer shall be marked in the field, and such marking shall be approved by the shoreline administrator prior to the commencement of permitted activities. Such field markings shall be maintained throughout the duration of the permit.
ii. A permanent physical demarcation along the upland boundary of the wetland buffer shall be installed and thereafter maintained. Such demarcation may consist of fencing, hedging or other prominent physical marking that allows wildlife passage, blends with the wetland environment, and is approved by the shoreline administrator.
iii. Permanent fencing of the wetland buffer on the outer perimeter shall be erected and thereafter maintained when there is a substantial likelihood of the presence of domestic grazing animals within the property unless the shoreline administrator determines that the animals would not degrade the functions of the wetland or buffer.
iv. Permanent signs shall be posted at an interval of one per lot for single-family residential uses or at a maximum interval of two hundred feet, or as otherwise determined by the shoreline administrator, and must be perpetually maintained by the property owner. The sign shall be worded as follows or with alternative language approved by the shoreline administrator: “The area beyond this sign is a wetland or wetland buffer. Alteration or disturbance is prohibited by law. Please call the City of Vancouver for more information.”
2. Compensatory Mitigation. Compensatory mitigation for impacts to wetlands shall be provided pursuant to VMC 20.740.060 and shall be consistent with the Department of Ecology Wetland Mitigation in Washington State, Part 1: Agency Policies and Guidance, Version 1, Ecology Publication No. 06-06-011a March 2006, or as revised by Ecology. Watersheds are defined in VMC 20.740.020(C)(2) and Chapter 20.150 VMC.
a. Mitigation for Lost or Affected Functions. Compensatory mitigation actions shall address functions affected by the alteration to achieve functional equivalency or improvement and shall provide similar wetland or buffer functions as those lost, except when:
i. The lost wetland or buffer provides minimal functions as determined by a site-specific function assessment, and the proposed compensatory mitigation action(s) will provide equal or greater functions or will provide functions shown to be limited within a watershed through a formal Washington State watershed assessment plan or protocol; or
ii. Out-of-kind replacement will best meet formally identified watershed goals, such as replacement of historically diminished wetland types.
b. Mitigation Actions.
i. Creation. The manipulation of the physical, chemical or biological characteristics present to develop a wetland on an upland or deepwater site where a biological wetland did not previously exist. Activities typically involve excavation of upland soils to elevations that will produce a wetland hydroperiod, hydric soils, and support the growth of hydrophytic plant species. Creation results in a gain in wetland acres and functions.
ii. Reestablishment. The manipulation of the physical, chemical or biological characteristics of a site with the goal of returning natural or historic functions to a former wetland. Activities could include removing fill material, plugging ditches or breaking drain tiles. Reestablishment results in a gain in wetland acres and functions.
iii. Rehabilitation. The manipulation of the physical, chemical or biological characteristics of a site with the goal of repairing natural or historic functions and processes of a degraded wetland. Activities could involve breaching a dike to reconnect wetlands to a floodplain, restoring tidal influence to a wetland, or breaking drain tiles and plugging drainage ditches. Rehabilitation results in a gain in wetland functions but not in wetland acres.
iv. Enhancement. The manipulation of the physical, chemical or biological characteristics of a biological wetland to increase or improve specific functions or to change the growth stage or composition of the vegetation present. Enhancement is undertaken for specified purposes such as water quality improvement, flood water retention or wildlife habitat. Activities typically consist of planting vegetation, controlling nonnative or invasive species, modifying site elevations to result in open water ponds, or some combination of these. Enhancement results in a change in certain wetland functions and can lead to a decline in other wetland functions. It does not result in a gain in wetland acres.
c. Type and Location of Mitigation. Compensatory mitigation for ecological functions shall be in kind. Compensatory mitigation shall be on site or within the impacted wetland’s: (i) contributing area; (ii) stream reach; (iii) sub-watershed; or (iv) watershed. (Sub-watersheds and watersheds are identified on the Clark County Digital Atlas.) The mitigation site shall be where the greatest level of wetland functions can be achieved. Mitigation actions may be conducted in a different watershed when:
i. Based on a determination of the natural capacity of the potential mitigation sites to mitigate for the impacts, there are no reasonable on-site or in-watershed opportunities, or those opportunities do not have a high likelihood of success. Consideration shall include: anticipated wetland mitigation replacement ratios, buffer conditions and proposed widths, hydrogeomorphic classes of on-site wetlands when restored, proposed flood storage capacity, and potential to impact riparian fish and wildlife habitat including connectivity; or
ii. Watershed goals for water quality, flood or conveyance, habitat or other wetland functions have been established and strongly justify location of mitigation at another site; or
iii. Credits from a certified wetland mitigation bank are used as mitigation and the use of credits is consistent with the terms of the bank’s certification.
d. Mitigation Ratios.
i. Replacement Ratios.
A. The replacement ratios shall apply to wetland mitigation that: (1) is for the same hydrogeomorphic subclass (e.g., riverine flow-through, depressional outflow or flats), and Cowardin class (e.g., palustrine emergent, palustrine forested or estuarine wetlands); (2) is on site; (3) is in the same category; (4) is implemented prior to or concurrent with alteration; and (5) has a high probability of success.
B. The replacement ratios are based on replacing the affected wetland with a compensation wetland of the same category, and hydogeomorphic (HGM) subclass and Cowardin class.
C. The replacement ratios do not apply to the use of credits from a state-certified wetland mitigation bank. When credits from a certified bank are used, replacement ratios should be consistent with the requirements of the bank’s certification.
D. Mitigation Ratios. Mitigation ratios are as follows (see subsection (C)(2)(b) of this section for definitions of mitigation actions):
|
Wetland Category and Type |
Reestablishment or Creation |
Rehabilitation |
Reestablishment or Creation (R/C) plus Rehabilitation (RH) |
Reestablishment or Creation (R/C) plus Enhancement (E) |
Enhancement Only |
|---|---|---|---|---|---|
|
Category I Bog |
Not Considered Possible |
6:1 Rehabilitation of a Bog |
R/C Not Considered Possible |
R/C Not Considered Possible |
Case-by-Case |
|
Category I Natural Heritage Site |
Not Considered Possible |
6:1 Rehabilitation of a Natural Heritage Site |
R/C Not Considered Possible |
R/C Not Considered Possible |
Case-by-Case |
|
Category I Forested |
6:1 |
12:1 |
1:1 R/C and 10:1 RH |
1:1 R/C and 20:1 E |
24:1 |
|
Category I Based on Score for Functions |
4:1 |
8:1 |
1:1 R/C and 6:1 RH |
1:1 R/C and 12:1 E |
16:1 |
|
Category II |
3:1 |
6:1 |
1:1 R/C and 4:1 RH |
1:1 R/C and 8:1 E |
12:1 |
|
Category III |
2:1 |
4:1 |
1:1 R/C and 2:1 RH |
1:1 R/C and 4:1 E |
8:1 |
|
Category IV |
1.5:1 |
3:1 |
1:1 R/C and 1:1 RH |
1:1 R/C and 2:1 E |
6:1 |
ii. Adjustment of Replacement Ratios. The shoreline administrator may adjust the replacement ratios to compensate for deviations from the requirements under subsection (C)(2)(d)(i)(A) of this section, subject to the following:
A. In most cases, adjustments to the replacement ratios will increase the required amount of mitigation. The required mitigation may be decreased under exceptional circumstances, for example, if programmatic out-of-kind mitigation yields watershed-scale benefits that would not be realized from in-kind mitigation, or if out-of-kind mitigation would protect irreplaceable wetlands.
e. Mitigation Timing. The mitigation shall be implemented prior to or concurrent with alterations. If mitigation is implemented after alteration is allowed, the planning official may require additional mitigation to compensate for temporal losses of wetland functions.
f. Buffers for Mitigation Wetlands. Refer to Wetland Buffer Tables 20.740.140-3 through 20.740.140-6.
g. Wetland Mitigation Banks.
i. Credits from a wetland mitigation bank may be approved for use as mitigation for unavoidable impacts to wetlands when:
A. The bank is certified under Chapter 173-700 WAC;
B. The shoreline administrator determines that the wetland mitigation bank provides appropriate mitigation for the authorized impacts; and
C. The proposed use of credits is consistent with the terms and conditions of the bank’s certification.
ii. Replacement ratios for projects using bank credits shall be consistent with replacement ratios specified in the bank’s certification.
iii. Credits from a certified wetland mitigation bank may be used to compensate for impacts located within the service area specified in the bank’s certification. In some cases, bank service areas may include portions of more than one adjacent drainage basin for specific wetland functions.