40.445.020    Designation

A.    General.

1.    Mapping.

a.    The county shall maintain an inventory consisting of mapping of areas where wetlands and fish and wildlife habitat conservation areas are likely to be present. The county inventory will be in a geographical information system (GIS) that includes the most current updates, from the listed sources of information, of the following:

(1)    Hydric soils (Natural Resources Conservation Service of U.S. Department of Agriculture (NRCS));

(2)    The National Wetland Inventory (U.S. Fish and Wildlife Service);

(3)    The Clark County wetland inventory model (Clark County);

(4)    Priority habitat and species areas (Washington State Department of Fish and Wildlife (WDFW));

(5)    Riparian habitat areas based on current water type and site classes (Washington State Department of Natural Resources);

(6)    Site potential tree height (NRCS soil survey); and

(7)    Site-specific mapping (Clark County responsible official).

b.    Clark County shall make mapping available to the public in accordance with data sharing agreements with the agencies responsible for maintaining the data.

2.    Site-Specific Determination. Upon submittal of an application for a stand-alone determination or a development permit, the responsible official shall determine the probable existence of wetlands, wetland buffers, and fish and wildlife habitat conservation areas on the site specified in the application based on site conditions. Determinations shall be based on application of the definitions in this section rather than the mapping.

3.    Responsibility. Assessments and analyses required for designation of wetlands, wetland buffers, and fish and wildlife habitat conservation areas are the responsibility of the applicant. The responsible official shall verify the accuracy of the applicant’s submittals and either concur with the findings or provide a written report identifying deficiencies that need to be resolved. In addition, the responsible official may meet with the applicant on the site to discuss any questions or deficiencies. The applicant may appeal the responsible official’s determination of deficiencies upon issuance of a determination or permit decision.

4.    Development Envelopes. The applicant may satisfy its responsibilities under Section 40.445.020(A)(3) by designating on proposed plans development envelopes that clearly avoid wetlands, wetland buffers, and fish and wildlife habitat conservation areas.

(Added: Ord. 2023-03-01)

B.    Wetlands

1.    Wetland is defined in Section 40.100.070.

2.    Wetland Delineation Required. Upon submittal of an application for a building or development permit, the responsible official shall determine the probable existence of wetlands or wetland buffers on the site specified in the application. If the responsible official finds that wetlands or wetland buffers probably exist on the site, a wetland delineation is required unless:

a.    The responsible official accepts development envelopes as allowed in Section 40.445.020(A)(4); or

b.    The application is subject to Type I review under Section 40.510.010 and relies on a wetland determination issued pursuant to Section 40.445.080(G).

3.    Wetland Delineation Methodology. The location of a wetland and its boundary shall be determined through the performance of a field investigation utilizing the methodology contained in the Wetlands Delineation Manual. If a wetland is located off site and is inaccessible, the best available information shall be used to determine the wetland boundary and category.

4.    Wetland Rating. Wetlands shall be rated according to the Washington State Department of Ecology (Ecology) Wetland Rating System for Western Washington (the rating system). Wetlands shall be mapped in assessment units, classified, and scored on the rating form in accordance with the rating system manual. The responsible official shall follow the recommendations of Ecology in interpreting the rating system.

a.    Wetland Rating Categories.

(1)    Category I. Category I wetlands represent a unique or rare wetland type, are more sensitive to disturbance than most wetlands, are relatively undisturbed and contain some ecological attributes that are impossible to replace within a human lifetime, or provide a very high level of functions. Category I wetlands are:

(a)    Wetlands that are identified by scientists of the Washington Natural Heritage Program/DNR as having high conservation value;

(b)    Bogs;

(c)    Mature and old growth forested wetlands, as defined by WDFW priority habitat and species provisions, larger than one (1) acre; or

(d)    Wetlands that function at high levels, as characterized by a score of twenty-three (23) or greater on the rating form.

(2)    Category II. Category II wetlands are difficult, though not impossible, to replace, and provide high levels of some functions. These wetlands occur more commonly than Category I wetlands, but they still need a relatively high level of protection. Category II wetlands are wetlands that perform functions well, as characterized by a score of twenty (20) through twenty-two (22) on the rating form.

(3)    Category III. Category III wetlands are wetlands with a moderate level of functions, as characterized by a score of sixteen (16) through nineteen (19) on the rating form. Generally, wetlands in this category have been disturbed in some ways and are often less diverse or more isolated from other natural resources in the landscape than Category II wetlands.

(4)    Category IV. Category IV wetlands have the lowest levels of functions and are often heavily disturbed. They are characterized by a score of less than sixteen (16) on the rating form. These are wetlands that should be replaceable, and in some cases may be improved. However, experience has shown that replacement cannot be guaranteed in any specific case. These wetlands may provide some important functions, and also need to be protected.

b.    Date of Wetland Rating. Wetland rating categories shall be applied as the wetland exists on the date of adoption of the rating system by the local government, as the wetland naturally changes thereafter, or as the wetland changes in accordance with permitted activities. Wetland rating categories shall not change due to illegal modifications.

5.    Wetland Buffers. Wetland buffers are required to protect wetland functions and values. The following standards shall be used to designate wetland buffers:

a.    Buffer widths are established by comparing the wetland rating category, the wetland rating habitat score, and the intensity of land uses proposed on development sites per Tables 40.445.020-1, 40.445.020-2 and 40.445.020-3. For Category IV wetlands, the required water quality buffers in Table 40.445.020-1 are adequate to protect habitat functions.

b.    Land use intensity is determined by the highest intensity in Table 40.445.020-1 that applies to the development proposed in the application.

 

Table 40.445.020-1 Land Use Intensity Matrix 

Intensity	Lot/Site Size1	Extent of Development	Extent of Vegetation (Moderate/High Habitat Function Only)	Public Roads and Utilities2
Low	5 acres or greater	No greater than 10% total effective impervious surface on the site	65% native or naturalized total cover retained on the site	Less than 300 sq. ft. developed area
Moderate	1 acre or greater but less than 5 acres	Greater than 10% but less than 25% total effective impervious surface on the site	40% – 64% native or naturalized total cover retained on the site	Maintenance access roads up to 12 feet wide; or between 2,000 sq. ft. and 300 sq. ft. of developed area
High	Less than 1 acre	25% total effective impervious surface or greater on the site	Less than 40% native or naturalized total cover retained on the site	Maintenance access roads greater than 12 feet wide; or Greater than 2,000 sq. ft. of developed area

1Measured as density averaged over a site, not individual lot sizes within a site.

2Within a right-of-way, easement or tract.

 

Table 40.445.020-2. Buffers Required to Protect Habitat Functions in Category I, II and III Wetlands 

Habitat Score in the Rating Form	Low Intensity Use	Moderate Intensity Use	High Intensity Use
5 points or less	See Table 40.445.020-3	See Table 40.445.020-3	See Table 40.445.020-3
6 or 7 points	75 ft.	110 ft.	150 ft.
8 or 9 points	150 ft.	225 ft.	300 ft.
Wetlands of high conservation value with a habitat score of 7 points or less	125 ft.	190 ft.	250 ft.

 

Table 40.445.020-3. Buffers Required to Protect Water Quality Functions 

Wetland Rating	Low Intensity Use	Moderate Intensity Use	High Intensity Use
Category I or II	50 ft.	75 ft.	100 ft.
Category III	40 ft.	60 ft.	80 ft.
Category IV	25 ft.	40 ft.	50 ft.

c.    All wetland buffers shall be measured horizontally outward from the wetland boundary.

d.    The buffer widths in Tables 40.445.020-2 and 40.445.020-3 assume that the buffer is vegetated with a native plant community appropriate for the ecoregion. If the existing buffer is unvegetated, sparsely vegetated, or vegetated with invasive species that do not perform needed functions, the buffer should either be planted to create the appropriate plant community or the buffer should be widened to ensure that adequate functions of the buffer are provided.

e.    Isolated wetlands that are less than one thousand (1,000) square feet with a habitat score less than six (6) points on the rating form and that do not contain federally listed species, or their critical habitat do not require wetland buffers.

f.    Functionally Isolated Wetland Buffers. Areas which are functionally separated from a wetland and do not protect the wetland from adverse impacts, such as legally established impervious surfaces and structures, shall be excluded from wetland buffers.

(Added: Ord. 2023-03-01)

C.    Fish and Wildlife Habitat Conservation Areas.

1.    Definitions.

a.    Priority Habitat and Species List. Fish and wildlife habitat conservation areas shall be identified by and consistent with statewide priority habitats and species definitions pursuant to the Washington Department of Fish and Wildlife Priority Habitats and Species List and include recommended management areas or buffers for species point sites. The county shall defer to WDFW in regards to classification and interpretation of priority habitat species.

b.    Riparian Habitat Areas. Riparian priority habitat is designated based on the estimated average two hundred (200) year site potential tree height, extending outward on each side of the stream (as defined in Section 40.100.070, Definitions) from the ordinary high water mark (as defined in Section 40.460.800) to the distances in Table 40.445.020-1 for each site class (defined in WAC 222-16-010) by water type (defined in WAC 222-16-030).

 

Table 40.445.020-4 Riparian Habitat Areas 

Site Class*	Type S and F Waters	Type Np Waters	Type Ns Waters
II	235	155	100
III	205	135	100
IV	165	105	100
V	150	100	100

*No Site Class I soils are mapped in Clark County.

c.    Functionally Isolated Riparian Habitat Areas. Riparian habitat areas which are at least one hundred (100) feet from the ordinary high water mark and disconnected from the water body by a continuous public or private roadway serving three (3) or more lots shall be excluded from fish and wildlife habitat conservation areas.

d.    Habitats of Local Importance. This subsection shall apply to habitat areas that do not meet priority habitat and species definitions but have been otherwise legislatively designated and mapped pursuant to Section 40.445.020(A)(1)(a)(7). The criteria for mapping of these areas are that they possess unusual or unique habitat warranting protection because of qualitative species diversity or habitat system health indicators. Recommendations for mapping areas meeting these criteria may be submitted by any person or group, and shall be reviewed annually by the county in conjunction with the plan amendments docket process as specified by Section 40.560.030 (Amendments Docket). Written notice of any such recommendations deemed to merit formal consideration shall be provided to impacted property owners. Such recommendations will not be reviewed as part of individual development requests.

2.    Site-Specific Determination. The responsible official shall follow recommendations provided by WDFW in the interpretation of site-specific conditions as they relate to the definitions of priority habitat and species areas and water types.

(Added: Ord. 2023-03-01)