Chapter 19.03
WETLANDS
Sections:
19.03.060 Report requirements.
19.03.010 Purpose.
The purposes of this chapter are to:
A. Recognize and protect the beneficial functions performed by many wetlands, which include, but are not limited to, providing food and habitat for breeding, nesting, and/or rearing for fish and wildlife; recharging and discharging groundwater; contributing to stream flow during low flow periods; stabilizing streambanks and shorelines; storing storm and flood waters to reduce flooding and erosion; and improving water quality through biofiltration, adsorption, and retention and transformation of sediments, nutrients, and toxicants.
B. Regulate land use to avoid adverse effects on wetlands and maintain the functions and values of wetlands throughout Skamania County.
C. Establish review procedures for development proposals in and adjacent to wetlands. (Ord. 2020-03, 2-25-20)
19.03.020 Applicability.
The provisions of this chapter apply to all regulated activities in wetlands or wetland buffers listed in Section 19.01.060 and all activities not specifically listed as exempt in Section 19.01.070 or 19.03.030.
For the purposes of this section, the division between eastern and western Washington is the Cascade Mountains from the international border to the top of Mount Adams, then the ridgeline dividing the White Salmon River drainage from the Lewis River drainage and the ridgeline dividing the Little White Salmon River drainage from the Wind River drainage to the Washington-Oregon state line (WAC 222-16-010). Communities in western Washington include Washougal, Prindle, Skamania, North Bonneville, Stevenson, Carson, Stabler, and Home Valley. Communities in eastern Washington include Mill A, Willard, and Underwood. (Ord. 2020-03, 2-25-20)
19.03.030 Exemptions.
A. The following wetlands may be exempt from the requirements to avoid impacts (Section 19.01.090(B)(1)), and they may be filled if the impacts are fully mitigated based on the remaining actions in Sections 19.01.090(B)(2) through (6). If available, impacts should be mitigated through the purchase of credits from an in-lieu fee program or mitigation bank, consistent with the terms and conditions of the program or bank. In order to verify the following conditions, a critical area report for wetlands meeting the requirements in Section 19.03.060 must be submitted. Nonfederally regulated wetlands are still regulated by Ecology. This provision does not exempt the applicant from securing authorization from Ecology to impact the types of wetlands listed below.
1. Exempt Wetlands in Western Washington.
a. All nonfederally regulated Category IV wetlands less than four thousand square feet that:
i. Are not associated with riparian areas or their buffers;
ii. Are not associated with shorelines of the state or their associated buffers;
iii. Are not part of a wetland mosaic;
iv. Do not score six or more points for habitat function based on the Washington State Department of Ecology Washington State Wetland Rating System for Western Washington: 2014 Update; or as amended; and
v. Do not contain a priority habitat or a priority area for a priority species identified by the Washington Department of Fish and Wildlife, or do not contain federally listed species or their critical habitat or species of local importance identified in Chapter 19.05.
b. Wetlands less than one thousand square feet that meet the above criteria and do not contain federally listed species or their critical habitat are exempt from the buffer provisions contained in this chapter.
2. Exempt Wetlands in Eastern Washington.
a. Small nonfederally regulated wetlands in arid landscapes often have a higher value and perform greater functions than in other settings. However, in certain circumstances, applying the buffers in Tables 19.03-1 and 19.03-2 may result in buffer areas that are greater than the area of the wetland being protected. In these instances, the county may consult with the Washington Department of Ecology (Ecology) to determine whether exemptions from mitigation sequencing and/or reduced buffers are warranted.
B. Existing and Ongoing Agricultural Activities. Existing agricultural activities are encouraged to implement applicable best management practices (BMPs) contained in the latest editions of the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Field Office Technical Guide.
C. Conservation, preservation, or restoration activities for soil, water, vegetation, fish, and/or other wildlife that improve or do not change the structure or functions of the existing wetland.
D. Removal of any invasive vegetation designated by the Skamania County noxious weed control program including but not limited to English ivy (Hedera helix), Himalayan blackberry (Rubus armeniacus), evergreen blackberry (Rubus laciniatus), giant knotweed (Polygonum sachalinense), Himalayan knotweed (Polygonum polystachyum), and Japanese knotweed (Polygonum cuspidatum) utilizing the best management practices for species present. (Ord. 2020-03, 2-25-20)
19.03.040 Regulations.
A. Wetland Delineation.
1. Wetlands shall be identified and delineated by a qualified wetland professional in accordance with WAC 173-22-035 and designated based on the definitions, methods and standards set forth in the currently approved federal wetland delineation manual and applicable regional supplements. All areas within the county meeting the wetland designation criteria in those procedures are hereby designated critical areas and are subject to the provisions of this chapter. Wetland delineations are valid for five years; after such date, the county shall determine whether a revision or additional assessment is necessary.
2. A full wetland delineation shall not be required when a project applicant submits a letter written by a qualified wetland professional that demonstrates that a proposed use or activity will be located outside of wetlands and any applicable wetland buffers. Wetland categories must be established in accordance with subsection (B) of this section and buffers must be established in accordance with subsection (C) of this section when a proposed use or activity is within three hundred feet of the wetland boundary.
B. Wetland Rating.
1. The determination of wetland ratings will be based on the entire extent of wetlands, unrelated to property lines or ownership patterns. Wetlands shall be rated according to the Washington State Wetland Rating System for Eastern Washington and/or Western Washington, as amended, published by Ecology.
a. Wetlands in Western Washington shall be rated according to Ecology’s wetland rating system, as set forth in the Washington State Wetland Rating System for Western Washington: 2014 Update (Ecology Publication No. 14-06-029, or as revised and approved by Ecology), which contains the definitions and methods for determining whether the criteria below are met.
i. Category I wetlands are (A) wetlands of high conservation value that are identified by scientists of the Washington Natural Heritage Program/Washington Department of Natural Resources (DNR); (B) bogs; (C) mature and old-growth forested wetlands larger than one acre; and (D) wetlands that perform many functions well (scoring twenty-three points or more). Category I wetlands: (A) represent unique or rare wetland types; (B) are more sensitive to disturbance than most wetlands; (C) are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or (D) provide a high level of functions.
ii. Category II wetlands are wetlands with a moderately high level of functions (scoring between twenty and twenty-two points).
iii. Category III wetlands (A) are 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 wetlands have the lowest levels of functions (scoring fewer than sixteen points) and are often heavily disturbed.
b. Wetlands in Eastern Washington shall be rated in accordance with Ecology’s wetland rating system, as set forth in the Washington State Wetland Rating System for Eastern Washington (Ecology Publication No. 04-06-015, or as revised and approved by Ecology), which contains the definitions and methods for determining whether the criteria below are met.
i. Category I wetlands are (A) alkali wetlands; (B) wetlands that are identified by scientists of the Washington Natural Heritage Program/Department of Natural Resources (DNR) as high-quality wetlands; (C) bogs and calcareous fens; (D) mature and old-growth forested wetlands over one-quarter acre with slow-growing trees; (E) forests with stands of aspen; and (F) wetlands that perform many functions very well (scores of twenty-two points or more).
ii. Category II wetlands are (A) forested wetlands in the floodplains of rivers; (B) mature and old-growth forested wetlands over one-quarter acre with fast-growing trees; (C) vernal pools; and (D) wetlands that perform functions well (scores between nineteen and twenty-one points).
iii. Category III wetlands are wetlands with a moderate level of functions (scores between sixteen and eighteen points) and can often be adequately replaced with a well-planned mitigation project.
iv. Category IV wetlands have the lowest levels of functions (scores less than sixteen points) and are often heavily disturbed.
2. Illegal Modifications. Wetland ratings categories shall not change due to illegal modifications made by the applicant or with the applicant’s knowledge.
C. Wetland Buffers, Averaging, and Reductions.
1. Buffer Requirements. The standard buffer widths for Category I wetlands are shown in Table 19.03-1. These buffer widths are based on the proposed land use intensity and the habitat score as determined by a qualified wetland professional using Ecology’s wetland rating system, and the applicable land use intensities are listed in Table 19.03-3. The standard wetland buffer widths for Category II, Category III, and Category IV wetlands are shown in Table 19.03-2. These buffers are the same for all land use intensities.
|
Habitat Score in Rating Form |
Low Intensity Use (ft) |
Moderate Intensity Use (ft) |
High Intensity Use (ft) |
|---|---|---|---|
|
Western Washington |
|||
|
5 points or less |
50 |
85 |
100 |
|
6 |
75 |
120 |
150 |
|
7 |
100 |
155 |
200 |
|
8 |
125 |
190 |
250 |
|
9 |
150 |
225 |
300 |
|
Eastern Washington |
|||
|
5 points or less |
50 |
75 |
100 |
|
6 |
70 |
95 |
125 |
|
7 |
80 |
110 |
150 |
|
8 |
90 |
135 |
175 |
|
9 |
100 |
150 |
200 |
|
Wetland Category |
Buffer Width (ft) |
|---|---|
|
Category II |
100 |
|
Category III |
50 |
|
Category IV |
25 |
|
Intensity |
Parks and Recreation |
Streets and Roads |
Stormwater Facilities |
Utilities |
Commercial/Industrial |
Residential2 |
|---|---|---|---|---|---|---|
|
Low |
Natural fields and grass areas, viewing areas, split rail fencing |
NA |
Outfalls, spreaders, constructed wetlands, bioswales, vegetated detention basins, overflows |
Underground and overhead utility lines, manholes, power poles (without footings) |
NA |
NA |
|
Moderate |
Impervious trails, engineered fields, fairways |
Residential driveways and access roads |
Wet ponds |
Maintenance access roads |
NA |
Single-family with density less than 1 unit per acre |
|
High |
Greens, tees, structures, parking, lighting, concrete or gravel pads, security fencing |
Public and private streets, security fencing, retaining walls |
Maintenance access roads, retaining walls, vaults, infiltration basins, sedimentation forebays and structures, security fencing |
Paved or concrete surfaces, structures, facilities, pump stations, towers, vaults, security fencing, etc. |
All site development |
Single- and multifamily with density higher than 1 unit per acre |
1 The county planning staff shall determine the intensity categories that apply to proposals should their characteristics not be specifically listed in Table 19.03-3.
2 Measured as density averaged over a site, not individual lot sizes.
2. When impervious surfaces from previous development completely functionally isolate the buffer from the wetland, the wetland buffer shall extend from the edge of the boundary of the delineated wetland to the impervious surfaces.
3. Any wetland created as compensation for an approved wetland alteration shall have the standard buffer required for the category. For Category I wetlands, the standard buffer shall also be based upon the habitat score and land use intensity of the created wetland expected at the end of the monitoring period. Wetlands to be created shall be located such that the buffer associated with the new wetland does not cross onto adjacent property, unless the same property owner owns the adjacent property.
4. Buffer Averaging. Buffer averaging is allowed in accordance with Section 19.01.080(D)(5).
5. Measurement of Wetland Buffers. See Section 19.01.080(D).
6. Buffer Maintenance. Except as otherwise specified or allowed in accordance with this chapter, wetland buffers shall be retained in an undisturbed or enhanced condition. In the case of compensatory mitigation sites, the removal of invasive nonnative weeds is required for the duration of the monitoring period (Section 19.01.090).
7. Impacts to Buffers. Requirements for the compensation for impacts to buffers are outlined in Section 19.03.050.
D. Development Standards within Wetlands and Buffers. When permitted through a critical areas review or variance, development within wetlands and buffers is subject to the following standards subject to preparation of a critical areas report including a mitigation plan for unavoidable impacts to critical areas or buffers.
1. Subdivisions. In the case of all subdivisions, a wetland and its buffer must be set aside in a nonbuildable open space tract or conservation easement. Residential density may be transferred out of critical areas in accordance with the cluster development standards in Section 21.70.150.
2. Public Roads and Utilities.
a. The expansion of the footprints of public roads and utilities may occur within wetland and buffer areas not to exceed 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.
b. Public and private utility corridors may be allowed within wetland buffers only for Category II, III, and IV wetlands when no lesser impacting alternative alignment is feasible, and wetland and wetland buffer functions and values will not be degraded. Utilities, whenever possible, shall be constructed in existing improved roads, drivable surfaces or shoulders subject to compliance with road maintenance BMPs, or within existing utility corridors. Otherwise, corridor alignment, construction, restoration, and maintenance shall adhere to the following criteria:
i. Corridor alignment shall be limited to the outer twenty-five percent of the buffer width, except when crossing a Category IV wetland and its buffer; or if installed using drilling techniques;
ii. Corridor construction and maintenance shall maintain and protect the ecological functions of the wetland and the buffer;
iii. Corridors shall be fully revegetated with appropriate native vegetation upon completion of construction; and
iv. Utilities requiring maintenance roads shall be prohibited in wetlands and wetland buffers unless the following criteria are met:
(A) There are no lesser impacting alternatives;
(B) Any required maintenance roads shall be no wider than fifteen feet. Roads shall be located as close as is practicable to the utility to minimize disturbances; and
(C) The maintenance road shall be constructed of pervious materials and designed to maintain and protect the ecological functions of the wetland and its buffer.
c. Drilling for Utilities/Utility Corridors. When drilling under a wetland for the installation of utilities or utility corridors, entrance and exit portals must be located completely outside the wetland buffer; provided, that the drilling does not interrupt the groundwater connection to the wetland or the percolation of surface water down through the soil column. Studies by a hydrologist are necessary to determine whether the groundwater connection to the wetland or the percolation of surface water down through the soil column will be disturbed.
3. Stormwater Management Facilities. A wetland or its buffer can be physically or hydrologically altered to meet the requirements of a low-impact development, runoff treatment, or flow control BMP if all of the following criteria are met:
a. The wetland is classified as a Category IV or a Category III wetland with a habitat score of three to five points; and
b. Functions and values of the wetland are protected; and
c. The wetland does not contain a breeding population of any native amphibian species; and
d. The hydrologic functions of the wetland can be improved as outlined in questions 3, 4, and 5 of Chart 4 and questions 2, 3, and 4 of Chart 5 in the “Guide for Selecting Mitigation Sites Using a Watershed Approach” (available here: http://www.ecy.wa.gov/biblio/0906032.html); or the wetland is part of a priority restoration plan that achieves restoration goals identified in a shoreline master program or other local or regional watershed plan; and
e. The wetland lies in the natural routing of the runoff, and the discharge follows the natural drainage; and
f. All regulations regarding stormwater and wetland management are followed, including, but not limited to, local and state wetland and stormwater codes, manuals, and permits; and
g. Modifications that alter the structure of a wetland or its soils will require permits. Existing functions and values that are lost will have to be compensated/replaced.
4. Passive Recreation Facilities. If not using the buffer flexibility options in Section 19.01.080, the following uses may be permitted within a wetland buffer, provided they are not prohibited by any other applicable law and are conducted in a manner that minimizes impacts to the buffer and adjacent wetland:
a. Walkways and trails may be permitted; provided, that they are generally parallel to the perimeter of the wetland, are located in the outer twenty-five percent of the buffer area, are constructed with a surface that does not interfere with soil permeability, and their surface is no more than five feet wide. The design and construction of walkways and trails shall avoid impacts to established native woody vegetation. Raised boardwalks using nontreated materials are acceptable.
b. Wildlife Viewing Structures. Wildlife viewing structures may be permitted provided they are associated with a walkway or trail, are located in the outer twenty-five percent of the buffer area, are constructed with a surface that does not interfere with soil permeability, and their surface is no more than eight feet wide. The design and construction of wildlife viewing structures shall avoid impacts to established native woody vegetation. Raised platforms utilizing nontreated pilings are acceptable.
c. All removed plant material shall be taken away from the site and disposed of appropriately; plants that appear on the Washington State Noxious Weed Control Board list of noxious weeds must be handled and disposed of according to a noxious weed control plan appropriate to that species.
d. If invasive vegetation is removed from wetlands or other water bodies, only chemical herbicides approved by the U.S. Environmental Protection Agency for use in aquatic environments may be employed.
e. Aquatic herbicides can be used or applied only by certified applicators or persons under the direct supervision of a certified applicator, and only for those uses covered by the certified applicator’s license category. Applicators are required to be permitted under Ecology’s noxious weed control permit. Applicators shall comply with all conditions of the noxious weed control permit.
f. Revegetation with appropriate native species at natural densities is allowed and encouraged in conjunction with removal of invasive plant species. (Ord. 2020-03, 2-25-20)
19.03.050 Wetland mitigation.
A. Protection of wetland functions and values shall occur as a result of the overall project. Only unavoidable wetland impacts will be authorized. In addition to the requirements in Section 19.01.090, General mitigation requirements for all critical areas, the following mitigation measures to minimize and reduce wetland impacts shall be required:
1. Mitigation shall achieve equivalent or greater biological functions. Mitigation plans shall be consistent with Ecology’s publication Wetland Mitigation in Washington State: Part 2 – Developing Mitigation Plans, 2006, or as revised.
|
Wetland to Be Replaced |
Reestablishment |
Rehabilitation |
Reestablishment |
Reestablishment |
Enhancement |
|---|---|---|---|---|---|
|
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 |
|
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 II |
3:1 |
6:1 |
1:1 R/C and 4:1 RH |
1:1 R/C and 8:1 E |
12:1 |
|
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 I, Natural Heritage Site |
Not Considered Possible |
6:1 Rehabilitate a Natural Heritage Site |
N/A |
N/A |
Case-by-Case |
B. Requirements for Compensatory Mitigation.
1. Compensatory mitigation for alterations to wetlands shall be used only for impacts that cannot be avoided or minimized and shall achieve equivalent or greater biologic functions. Compensatory mitigation plans shall be consistent with Wetland Mitigation in Washington State – Part 2: Developing Mitigation Plans – Version 1 (Ecology Publication No. 06-06-011b, March 2006 or as revised), and Selecting Wetland Mitigation Sites Using a Watershed Approach (Eastern Washington) (Ecology Publication No. 10-06-07, November 2010) or Selecting Wetland Mitigation Sites Using a Watershed Approach (Western Washington) (Ecology Publication No. 09-06-032, December 2009).
2. Mitigation ratios for permittee-responsible mitigation shall be consistent with Table 19.03-4. Requiring a greater area for mitigation than the wetland area that will be impacted helps offset the risk that compensatory mitigation will fail as well as the temporal loss of functions that may occur.
3. Mitigation requirements may also be determined using the credit/debit tool described in “Calculating Credits and Debits for Compensatory Mitigation in Wetlands of Eastern Washington: Final Report” (Ecology Publication No. 11-06-015, August 2012) or “Calculating Credits and Debits for Compensatory Mitigation in Wetlands of Western Washington: Final Report” (Ecology Publication No. 10-06-011, March 2011), consistent with subsection (G)(2) of this section.
C. Compensating for Lost or Affected Functions. Compensatory mitigation shall address the functions affected by the proposed project, with the intention of achieving functional equivalency or the improvement of functions. The goal shall be for the compensatory mitigation to provide wetland functions similar to those lost, except when either:
1. The lost wetland provides minimal functions, and the proposed compensatory mitigation action(s) will provide equal or greater functions, or will provide functions shown to be limiting within a watershed through a formal Washington watershed assessment plan or protocol; or
2. Out-of-kind replacement of wetland type or functions will best meet watershed goals formally identified by the county, such as replacement of historically diminished wetland types.
D. Preference of Mitigation Actions. Mitigation actions that require compensation shall occur in the following order of preference:
1. Wetland Mitigation Banks. Credits from a certified wetland mitigation bank may be used to compensate for impacts located within the service area specified in the mitigation bank instrument. Use of credits from a wetland mitigation bank certified under Chapter 173-700 WAC is allowed if:
a. The county determines that the use of credits would provide appropriate compensation for the proposed impacts; and
b. The impact site is located in the service area of the bank; and
c. The proposed use of credits is consistent with the terms and conditions of the certified mitigation bank instrument; and
d. Replacement ratios for projects using bank credits is consistent with replacement ratios specified in the certified mitigation bank instrument.
2. In-Lieu Fee Mitigation. To help implement off-site mitigation, the county may develop an in-lieu fee program. It shall be developed and approved through a public process and be consistent with federal rules, state policy regarding in-lieu fee mitigation, and state water quality regulations. An approved in-lieu fee program sells compensatory mitigation credits to permittees whose obligation to provide compensatory mitigation is then transferred to the in-lieu program sponsor, a governmental or nonprofit natural resource management entity.
Credits from an approved in-lieu fee program may be used when all of the following apply:
a. The county determines that these credits would provide environmentally appropriate compensation for the proposed impacts; and
b. The proposed use of credits is consistent with the terms and conditions of the approved in-lieu fee program instrument; and
c. Projects using in-lieu fee credits shall have debits associated with the proposed impacts calculated by the applicant’s qualified wetland professional using the credit assessment method specified in the approved instrument for the in-lieu fee program; and
d. The impacts are located within the service area specified in the approved in-lieu fee instrument.
3. Permittee-Responsible Mitigation. In this situation, the permittee or responsible party performs the mitigation after the permit has been issued and is ultimately responsible for implementation and success of the mitigation. Permittee-responsible mitigation may occur at the site of the permitted impacts or at an off-site location within the same watershed. Permittee-responsible mitigation shall be used only if the applicant’s qualified wetland professional demonstrates to the approval authority’s satisfaction that the proposed approach is ecologically preferable to the use of a bank or in-lieu fee program, consistent with the criteria in this section.
a. Restoration. For the purpose of tracking net gains in wetland acres, restoration is divided into:
i. Reestablishment. The goal of reestablishment is to return the natural or historic functions to a former wetland.
ii. Rehabilitation. The goal of rehabilitation is to repair the natural or historic functions of an existing degraded wetland.
b. Establishment (Creation). The goal of establishment is to develop a wetland from an upland or deepwater site where a wetland did not previously exist.
c. Enhancement. The goal of enhancement is to heighten, intensify, or improve specific functions, or to change the growth stage or composition of existing vegetation with a wetland.
d. Protection/Maintenance (Preservation). Removing a threat to, or preventing the decline of, wetland conditions by an action in or near a wetland. This includes appropriate legal and physical mechanisms (such as recording conservation easements and providing structural protections like fences and signs and repairing water control structures). Preservation does not result in a gain of wetland acres. Permanent protection of a Category I or II wetland and its associated buffer at risk of degradation can be used only if:
i. The county determines that the proposed preservation is the best mitigation option.
ii. The proposed preservation site is under threat of undesirable ecological change due to permitted, planned, or likely actions that will not be adequately mitigated under existing regulations.
iii. The area proposed for preservation is of high quality or critical for the health of the watershed or basin due to its location. Some of the following features may be indicative of high-quality sites:
(A) Category I or II wetland rating (using the appropriate wetland rating system for eastern or western Washington);
(B) Rare or irreplaceable wetland type (for example, bogs, mature forested wetlands, estuarine wetlands) or aquatic habitat that is rare or a limited resource in the area;
(C) Habitat for priority or locally important wildlife species;
(D) Provides biological and/or hydrological connectivity; and
(E) Priority sites in an adopted watershed plan.
e. Permanent preservation of the wetland and buffer will be provided through a conservation easement or tract held by an appropriate natural land resource manager (such as a land trust) that provides permanent preservation of the wetland and buffer.
f. The county may approve other legal and administrative mechanisms in lieu of a conservation easement if it determines they are adequate to protect the site.
g. Ratios for preservation in combination with other forms of mitigation generally range from 10:1 to 20:1, as determined on a case-by-case basis, depending on the quality of the wetlands being impacted and the quality of the wetlands being preserved. Ratios for preservation as the sole means of mitigation generally start at 20:1.
E. Location of Compensatory Mitigation. Compensatory mitigation actions shall generally be conducted within the same sub-drainage basin and on the site of the alteration except when the applicant can demonstrate that off-site mitigation is ecologically preferable. The following criteria will be evaluated when determining whether the proposal is ecologically preferable. When considering off-site mitigation, preference should be given to using alternative mitigation, such as a mitigation bank, an in-lieu fee program, or advance mitigation.
1. There are no reasonable opportunities on site or within the sub-drainage basin (e.g., on-site options would require elimination of high-functioning upland habitat), or opportunities on site or within the sub-drainage basin do not have a high likelihood of success based on a determination of the capacity of the site to compensate for the impacts. Considerations should include: anticipated replacement ratios for wetland mitigation, buffer conditions and proposed widths, available water to maintain anticipated hydrogeomorphic classes of wetlands when restored, proposed flood storage capacity, and potential to mitigate riparian fish and wildlife impacts (such as connectivity).
2. On-site mitigation would require elimination of high-quality upland habitat.
3. Off-site mitigation has a greater likelihood of providing equal or improved wetland functions than the altered wetland.
4. Off-site locations shall be in the same sub-drainage basin unless:
a. Established watershed goals for water quality, flood storage or conveyance, habitat, or other wetland functions have been established by the county and strongly justify location of mitigation at another site; or
b. Credits from a state-certified wetland mitigation bank are used as compensation, and the use of credits is consistent with the terms of the certified bank instrument; or
c. Fees are paid to an approved in-lieu fee program to compensate for the impacts.
5. The design for the compensatory mitigation project needs to be appropriate for its location (i.e., position in the landscape). Therefore, compensatory mitigation should not result in the creation, restoration, or enhancement of an atypical wetland.
F. Timing for compensatory mitigation shall comply with Section 19.01.090(E)(4).
G. Compensatory Mitigation Plan. When a project involves wetland and/or buffer impacts, a compensatory mitigation plan prepared by a qualified professional meeting the following minimum standards shall be required:
1. Wetland Critical Area Report. A critical area report for wetlands must accompany or be included in the compensatory mitigation plan and include the minimum parameters described in the report requirements in Section 19.03.060.
2. Compensatory Mitigation Report. The report must include a written report and plan sheets that must contain, at a minimum, the following elements. Complete guidance can be found in Wetland Mitigation in Washington State – Part 2: Developing Mitigation Plans (Version 1) (Ecology Publication No. 06-06-011b, March 2006, or as revised).
a. In addition to the requirements of Section 19.01.090(F), the written report must contain, at a minimum:
i. Description of how the project design has been modified to avoid, minimize, or reduce adverse impacts to wetlands.
ii. Description of the existing wetland and buffer areas proposed to be impacted. Include acreage (or square footage), water regime, vegetation, soils, landscape position, surrounding land uses, and functions. Also describe impacts in terms of acreage by Cowardin classification, hydrogeomorphic classification, and wetland rating, based on Section 19.03.040(B), Wetland Rating.
iii. Description of the compensatory mitigation site, including location and rationale for selection. Include an assessment of existing conditions: acreage (or square footage) of wetlands and uplands, water regime, sources of water, vegetation, soils, landscape position, surrounding land uses, and functions.
iv. Surface and subsurface hydrologic conditions, including an analysis of existing and proposed hydrologic regimes for created or restored compensatory mitigation areas. Include illustrations of how data for existing hydrologic conditions were used to determine the estimates of future hydrologic conditions.
v. A description of the proposed actions for compensation of impacts to wetland and upland areas affected by the project. Include overall goals of the proposed mitigation, including a description of the targeted functions, hydrogeomorphic classification, and categories of wetlands.
vi. A description of the proposed mitigation construction activities and timing of activities.
vii. Performance standards (measurable standards for years post-installation) for upland and wetland communities, a monitoring schedule, and a maintenance schedule and actions proposed by year.
viii. A discussion of ongoing management practices that will protect wetlands after the development project has been implemented, including proposed monitoring and maintenance programs (for remaining wetlands and compensatory mitigation wetlands).
ix. A financial guarantee as per Section 19.01.080.
x. Proof of establishment of notice on title for the wetlands and buffers on the project site, including the compensatory mitigation areas.
b. The scaled plan sheets for the compensatory mitigation must contain, at a minimum:
i. Surveyed edges of the existing wetland and buffers, proposed areas of wetland and/or buffer impacts, location of proposed wetland and/or buffer compensation actions.
ii. Existing topography, ground-proofed, at two-foot contour intervals in the zone of the proposed compensation actions if any grading activity is proposed to create the compensation area(s). Also existing cross sections of on-site wetland areas that are proposed to be impacted, and cross section(s) (estimated one-foot intervals) for the proposed areas of wetland or buffer compensation.
iii. Conditions expected from the proposed actions on site, including future hydrogeomorphic types, vegetation community types by dominant species (wetland and upland), and future water regimes.
iv. Required wetland buffers for existing wetlands and proposed compensation areas. Also, identify any zones where buffers are proposed to be reduced or enlarged outside of the standards identified in this chapter.
v. A planting plan for the compensation area, including all species by proposed community type and water regime, size and type of plant material to be installed, spacing of plants, typical clustering patterns, total number of each species by community type, and timing of installation.
H. Buffer Mitigation Ratios. Impacts to buffers shall be mitigated at a minimum 1:1 ratio. Compensatory buffer mitigation shall replace those buffer functions lost from development.
I. Protection of the Mitigation Site. The area where the mitigation occurred and any associated buffer shall be located in a critical area tract or a conservation easement consistent with Section 19.01.090.
J. Monitoring. Mitigation monitoring shall be required for a period necessary to establish that performance standards have been met, but not for a period less than five years. If a scrub-shrub or forested vegetation community is proposed, monitoring may be required for ten years or more. Monitoring shall be completed consistent with Section 19.01.090(G).
K. Advance Mitigation. Mitigation for projects with pre-identified impacts to wetlands may be constructed in advance of the impacts if the mitigation is implemented according to federal rules, state policy on advance mitigation, and state water quality regulations consistent with “Interagency Regulatory Guide: Advance Permittee Responsible Mitigation” (Ecology Publication No. 12-06-015, December 2012).
L. Alternative Mitigation Plans. The administrator may approve alternative wetland mitigation plans that are based on best available science. Alternative mitigation proposals must provide an equivalent or better level of protection of wetland functions and values than would be provided by the strict application of this chapter.
The administrator shall consider the following for approval of an alternative mitigation proposal:
1. The proposal uses a watershed approach consistent with “Selecting Wetland Mitigation Sites Using a Watershed Approach (Eastern Washington)” (Ecology Publication No. 10-06-07, November 2010) or “Selecting Wetland Mitigation Sites Using a Watershed Approach (Western Washington)” (Ecology Publication No. 09-06-032, December 2009).
2. Creation or enhancement of a larger system of natural areas and open space is preferable to the preservation of many individual habitat areas.
3. Mitigation according to Section 19.01.090 is not feasible due to site constraints such as parcel size, stream type, wetland category, or geologic hazards.
4. There is clear potential for success of the proposed mitigation at the proposed mitigation site.
5. The plan shall contain clear and measurable standards for achieving compliance with the specific provisions of the plan. A monitoring plan shall, at a minimum, meet the provisions in subsection (J) of this section.
6. The plan shall be reviewed and approved as part of the overall approval of the proposed use.
7. A wetland of a different type may be justified based on regional needs or functions and values; the replacement ratios may not be reduced or eliminated unless the reduction results in a preferred environmental alternative.
8. Mitigation guarantees shall meet the minimum requirements as outlined in subsection (G)(2)(a)(ix) of this section.
9. Qualified professionals in each of the critical areas addressed shall prepare the plan.
10. The county may consult with agencies with expertise and jurisdiction over the critical areas during the review to assist with the analysis and identification of appropriate performance measures that adequately safeguard critical areas. (Ord. 2020-03, 2-25-20)
19.03.060 Report requirements.
A. In addition to the general requirements for critical areas reports provided under Chapter 19.01, wetland critical area reports, prepared by a qualified professional, shall include items listed below. The administrator has the authority to determine the applicability of individual critical areas report requirements and may waive report requirements determined to be unnecessary on a case-by-case basis.
1. On the site map:
a. Wetlands shall be identified as delineated by a qualified wetland professional in accordance with WAC 173-22-035.
b. The location of any proposed wetland mitigation area(s) shall be identified.
c. The location of any proposed wetland or buffer alteration or fill shall be shown.
2. In the report:
a. A statement specifying the accuracy of the report and all assumptions made and relied upon.
b. Documentation of any fieldwork performed on the site, including field data sheets for delineations, rating system forms, baseline hydrologic data, etc.
c. A description of the methodologies used to conduct the wetland delineations, wetland ratings, or impact analyses including references.
d. Description of the wetland by classification per the Washington State Wetland Rating System for Eastern Washington (Ecology Publication No. 14-06-030 or as revised) or Western Washington (Ecology Publication No.14-06-029 or as revised).
e. General condition of the wetland.
f. Description of vegetation species and community types present in the wetland and surrounding buffer.
g. Description of soil types within the wetland and the surrounding buffer using the USDA Soil Conservation Service soil classification system.
B. Description of hydrologic regime and related findings.
C. A copy of the site plan sheet(s) for the project must be included with the written report and must include, at a minimum:
1. Maps (to scale) depicting delineated and surveyed wetland and required buffers on-site, including buffers for off-site critical areas that extend onto the project site; the development proposal; other critical areas; grading and clearing limits; areas of proposed impacts to wetlands and/or buffers (include square footage estimates).
2. A depiction of the proposed stormwater management facilities and outlets (to scale) for the development, including estimated areas of intrusion into the buffers of any critical areas. The written report shall contain a discussion of the potential impacts to the wetland(s) associated with anticipated hydroperiod alterations from the project. (Ord. 2020-03, 2-25-20)