40.450.030    Standards

A.    General. The standards apply whenever a nonexempt project (see Section 40.450.010(B)) is proposed on a parcel of real property containing a nonexempt wetland or wetland buffer (see Section 40.450.010(C)). The standard provisions shall be implemented in conjunction with the processing of the development permits listed in Section 40.450.010(B).

1.    For the purpose of computing the processing limitation period applicable to a development permit application, the application shall not be deemed fully complete until completion (if required) of the wetland determination pursuant to Section 40.450.030(C), the wetland delineation pursuant to Section 40.450.030(D), and the buffer designation pursuant to Section 40.450.030(E)(1). This subsection shall not be construed in any way to delay vesting under Washington law.

2.    Administrative appeals of determinations made under this section must be filed in conjunction with, and within the limitation period applicable to, an available administrative appeal of the development permit application; provided, that an aggrieved party may appeal preliminary decisions deciding an exemption, determining or delineating a wetland, determining a buffer, or otherwise finally applying the provisions of this chapter in the same manner, and within the limitation period applicable to, appeals from responsible official decisions under Chapter 40.510.

(Amended: Ord. 2019-03-05)

B.    Predetermination.

    Prior to submittal of a development permit application, a person may request from the responsible official a written predetermination of whether wetlands exist on any parcel less than forty (40) acres. An applicant may also choose to submit a digital file of delineated wetland boundaries consistent with Section 40.450.030(D)(3) or request staff to digitize the information. The predetermination shall be binding on the responsible official for a period of three (3) years; provided, that such predetermination shall be subject to administrative appeal upon its application in conjunction with a triggering application. The fee for a predetermination is contained in Chapter 6.110A.

(Amended: Ord. 2019-03-05)

C.    Wetland Determination.

    In conjunction with the submittal of a development permit application, the responsible official shall determine the probable existence of a wetland on the parcel involved in the development permit application. If wetlands or wetland buffers are found to exist on a parcel, wetland delineation is required.

(Amended: Ord. 2019-03-05)

D.    Wetland Delineation.

1.    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.

2.    Information Requirements. Wetland boundaries shall be staked and flagged in the field and a delineation report shall be submitted to the department. The report shall include the following information:

a.    USGS quadrangle map with site clearly defined;

b.    Topographic map of area;

c.    National wetland inventory map showing site;

d.    Soil Conservation Service soils map showing site;

e.    Site map, at a scale no smaller than one (1) inch equals one hundred (100) feet (1" = 100', a scaling ratio of 1:1,200), if practical, showing the following information:

(1)    Wetland boundaries,

(2)    Sample sites and sample transects,

(3)    Boundaries of forested areas,

(4)    Boundaries of wetland classes if multiple classes exist;

f.    Discussion of methods and results with special emphasis on technique used from the Wetlands Delineation Manual;

g.    Acreage of each wetland on the site based on the survey if the acreage will impact the buffer size determination or the project design;

h.    All completed field data sheets per the Wetlands Delineation Manual, numbered to correspond to each sample site.

3.    Digital File Submittal. Upon submittal of the wetland delineation report an application shall provide a digital file containing the layers specified in Table 40.450.030-1 that conforms to all applicable requirements discussed in Section 40.540.060. If the applicant chooses, the county will prepare the digital file based upon the wetland boundary survey map. The applicant shall provide payment for the preparation of the digital file in accordance with Section 6.110A.020(2)(B)(III). Additionally, the responsible official shall forward the digital file to the Department of Assessment and GIS.

Table 40.450.030-1. DXF Layers

Layer Description

Layer Name

Feature Type

Parcel Lines



Wetland Boundary



Wetland Buffers



Building Envelopes



PLSS Corner



Wetland Flags and Data Plots



Parcel Lot Numbers and Parent Parcel Number



Wetland Category



Buffer Distance



4.    Responsibility. The wetland delineation is the responsibility of the applicant. The responsible official shall verify the accuracy of the boundary delineation within ten (10) working days of receiving the delineation report. This review period may be extended when excessively dry conditions prohibit the confirmation of the wetland delineation. If the delineation is found to not accurately reflect the boundary of the wetland, the responsible official shall issue a report, within twenty (20) working days of receiving the applicant’s delineation report, citing evidence (for example, soil samples) that demonstrates where the delineation is in error. The applicant may then either revise the delineation and submit another report or administratively appeal.

(Amended: Ord. 2019-03-05)

E.    Buffers. Wetland buffer widths shall be determined by the responsible official in accordance with the standards below:

1.    All buffers shall be measured horizontally outward from the delineated wetland boundary or, in the case of a stream with no adjacent wetlands, the ordinary high water mark as surveyed in the field.

2.    Buffer widths are established by comparing the wetland rating category and the intensity of land uses proposed on development sites per Tables 40.450.030-2, 40.450.030-3 and 40.450.030-4. For Category IV wetlands, the required water quality buffers, per Table 40.450.030-2, are adequate to protect habitat functions.

Table 40.450.030-2. 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.

Table 40.450.030-3. 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 40.450.030-2

See Table 40.450.030-2

See Table 40.450.030-2

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 40.450.030-4. Land Use Intensity Matrix1  


Parks and Recreation

Streets and Roads

Stormwater Facilities





Natural fields and grass areas, viewing areas, split rail fencing


Outfalls, spreaders, constructed wetlands, bioswales, vegetated detention basins, overflows

Underground and overhead utility lines, manholes, power poles (without footings)


Density at or lower than 1 unit per 5 acres


Impervious trails, engineered fields, fairways

Residential driveways and access roads

Wet ponds

Maintenance access roads


Density between 1 unit per acre and higher than 1 unit per 5 acres


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

Density higher than 1 unit per acre

1 The responsible official shall determine the intensity categories applicable to proposals should characteristics not be specifically listed in Table 40.450.030-4.

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

3.    In urban plats and subdivisions, wetlands and wetland buffers shall be placed within a nonbuildable tract with the following exceptions:

a.    Creation of a nonbuildable tract would result in violation of minimum lot depth standards; or

b.    The responsible official determines a tract is impractical.

c.    Where the responsible official determines the exceptions in Section 40.450.030(E)(3)(a) or (b) apply, residential lots may extend into wetlands and wetland buffers; provided, that all the requirements of Section 40.450.030(F) are met.

4.    Adjusted Buffer Width.

a.    Adjustments Authorized by Wetland Permits. Adjustments to the required buffer width are authorized by Section 40.450.040(D) upon issuance of a wetland permit.

b.    Functionally Isolated Buffer Areas. Areas which are functionally separated from a wetland and do not protect the wetland from adverse impacts shall be treated as follows:

(1)    Preexisting roads, structures, or vertical separation shall be excluded from buffers otherwise required by this chapter;

(2)    Distinct portions of wetlands with reduced habitat functions that are components of wetlands with an overall habitat rating score greater than five (5) points shall not be subject to the habitat function buffers designated in Table 40.450.030-3 if all of the following criteria are met:

(a)    The area of reduced habitat function is at least one (1) acre in size;

(b)    The area supports less than five (5) native plant species and does not contain special habitat features listed in Section H1.5 of the rating form;

(c)    The area of reduced habitat function has low or no interspersion of habitats as defined in Section H1.4 of the rating form;

(d)    The area does not meet any WDFW priority habitat or species criteria; and

(e)    The required habitat function buffer is provided for all portions of the wetland that do not have reduced habitat function.

c.    Maximum Buffer Area. Except for streams, buffers shall be reduced as necessary so that total buffer area (on and off site) does not exceed two (2) times the total wetland area (on- and off-site); provided, the minimum buffer width at any point shall not be less than the water quality buffer widths for low intensity uses contained in Table 40.450.030-2.

(Amended: Ord. 2014-12-05; Ord. 2019-03-05)

F.    Standard Requirements. Any action granting or approving a development permit application shall be conditioned on all the following:

1.    Marking Buffer During Construction. The location of the outer extent of the wetland buffer shall be marked in the field and such markings shall be maintained throughout the duration of the permit.

2.    Permanent Marking of Buffer Area. A permanent physical demarcation along the upland boundary of the wetland buffer area shall be installed and thereafter maintained. Such demarcation may consist of logs, a tree or hedge row, fencing, or other prominent physical marking approved by the responsible official. In addition, small signs shall be posted at an interval of one (1) per lot or every one hundred (100) feet, whichever is less, and perpetually maintained at locations along the outer perimeter of the wetland buffer approved by the responsible official worded substantially as follows:

Wetland and Buffer –
Please retain in a natural state

3.    A conservation covenant shall be recorded in a form approved by the Prosecuting Attorney as adequate to incorporate the other restrictions of this section and to give notice of the requirement to obtain a wetland permit prior to engaging in regulated activities within a wetland or its buffer.

4.    In the cases of plats, short plats, and recorded site plans, include on the face of such instrument the boundary of the wetland and its buffer and a reference to the separately recorded conservation covenant provided for in Section 40.450.030(F)(3).

G.    Standard Requirements – Waivers. The responsible official shall waive the requirements of Sections 40.450.030(D) and (F) in certain cases described below if the applicant designates development envelopes which are clearly outside of any wetland or buffer. The responsible official may require partial wetland delineation to the extent necessary to ensure eligibility for this waiver:

1.    Residential building permits and home businesses;

2.    Land divisions in the rural area:

a.    Development envelopes shall be required for a fully complete preliminary application;

b.    Development envelopes shall be shown on the final plat; and

c.    A note referencing the development envelopes shall be placed on the final plat.

3.    Site plan reviews where the responsible official determines that all development is clearly separated from the wetlands and wetland buffers:

a.    Development envelopes shall be required for a fully complete preliminary application;

b.    Development envelopes shall be shown on the final site plan; and

c.    A note referencing the development envelopes shall be placed on the final site plan.

(Amended: Ord. 2005-04-12; Ord. 2006-05-27; Ord. 2012-07-03)