Source: https://www.codepublishing.com/WA/PierceCounty/html/PierceCounty18E/PierceCounty18E30.html
Timestamp: 2019-11-12 14:29:27
Document Index: 213153208

Matched Legal Cases: ['§ 4', '§ 6', '§ 2', '§ 4', '§4', '§ 2', '§ 4', '§ 1', '§ 4', '§ 4', '§ 4']

Chapter 18E.30 WETLANDS
Chapter 18E.30
18E.30.010 Purpose.
18E.30.020 Wetland Areas.
18E.30.030 Wetland Review Procedures.
18E.30.040 Wetland Standards.
18E.30.050 Mitigation Requirements.
18E.30.060 Buffer Requirements.
18E.30.070 Appendices.
A. Wetland Categories.
B. Information to be Included in a Wetland Analysis Report.
C. Mitigation Plan for Regulated Activities in Buffers.
D. Compensatory Mitigation Plan for Regulated Activities in Wetlands – Conceptual Phase.
E. Compensatory Mitigation Plan for Regulated Activities in Wetlands – Detailed Phase.
F. Width of Buffers by Category of Wetland
The purpose of this Chapter is to avoid impacts arising from land development and other activities affecting wetlands, and to maintain and enhance the biological and physical functions and values of wetlands with respect to water quality maintenance, stormwater and floodwater storage and conveyance, fish and wildlife habitat, primary productivity, recreation, education, and historic and cultural preservation. In appropriate circumstances it may be necessary to minimize, rectify, reduce, or compensate for wetland impacts. When wetland impacts occur, mitigation will be required to achieve no net loss of wetlands in terms of acreage, function, and value. (Ord. 2004-56s § 4 (part), 2004)
1. Wetlands are those areas that are inundated or saturated by surface water or groundwater 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.
2. The County will require the use of the following documents to determine the presence or absence of potential wetlands:
a. The most recent edition of the federal wetland delineation manual and applicable regional supplements approved by the Washington State Department of Ecology.
B. Wetland Indicators. Indicators of wetlands normally include, but are not limited to: saturated soils or standing water; water-tolerant plant species such as salmonberry, Oregon ash, Western red cedar, rushes and sedges; and dark-brown or black soil colors. Refer to the documents listed in PCC 18E.30.020 A.2. for detailed wetland indicator criteria.
C. Potential Wetland Areas. Potential wetland areas, as depicted on the Critical Areas Atlas – County Wetland Inventory Maps, are those areas where wetland indicators have been mapped or identified. Potential wetlands include:
1. Areas within 315 feet of: hydric soils identified on the Soil Survey of Pierce County and Soil Survey of Snoqualmie Pass area; wetlands identified on the National Wetland Inventory Maps or Pierce County Wetland Inventory Maps; areas of known flooding identified on the FEMA FIRM and Flood Insurance Study Maps; or any other indicators of hydrology such as Department of Natural Resource stream data.
2. Areas that possess one or a number of wetland indicators as set forth in PCC 18E.30.020 B. and any adjacent areas within 315 feet.
3. Areas within the buffer of any wetland previously identified through the wetland review process.
D. Wetland Categories. Wetlands shall be classified into categories which are reflective of each wetland's function and value and unique characteristics. Wetland categories shall be based on the generalized criteria provided in PCC 18E.30.070 – Appendix A and the specific criteria provided in the Washington State Wetland Rating System for Western Washington (Ecology Publication #04-06-025). Wetlands shall be generally designated as follows:
1. Category I Wetlands. Category I wetlands are those regulated wetlands of exceptional resource value based on their functional value and diversity, wetland communities of infrequent occurrence, association with documented habitat for sensitive, threatened or endangered animal species, and other attributes which may not be adequately replicated through creation or restoration.
2. Category II Wetlands. Category II wetlands are those regulated wetlands of significant resource value based on their functional value and diversity, wetland communities of infrequent occurrence, and other attributes which may not be adequately replicated through creation or restoration.
3. Category III Wetlands. Category III wetlands are those regulated wetlands that have important resource value, principally due to vegetative diversity.
4. Category IV Wetlands. Category IV wetlands are those regulated wetlands of ordinary resource value based on monotypic vegetation of similar age and class, lack of special habitat features, and isolation from other aquatic systems.
E. Wetland Categorization Criteria.
1. Categorizing Wetlands Divided by a Manmade Feature. When a wetland is divided by a manmade feature (e.g., a road embankment), the wetland shall be rated as if it is not divided if there is a perennial or intermittent surface water connection between the two wetlands and any of the following criteria are met:
a. It can be demonstrated that the separate wetlands were one discrete wetland prior to construction of the manmade feature. This may be accomplished through an analysis of secondary information such as aerial photographs and soils maps; or
b. The two separated wetlands can be shown to function as one wetland. This shall be determined based on normal conditions (i.e., in the absence of unauthorized activity, the wetlands possess similar vegetative or wildlife assemblages or hydrologic regime).
c. Separated wetland areas may be rated jointly in the absence of a perfectly level culvert where it can be demonstrated that a level surface water connection is present within the culvert that permits flow of water, fish, or other organisms in both directions. Separated wetland areas may be rated jointly in the absence of a perfectly level culvert with two-way water flow if the bottom of the culvert is below the high water marks in the receiving wetland or if the high water marks on either side differ by six inches or less in elevation.
2. Connecting Mosaic Pattern Wetlands. In cases where the wetlands to be categorized are smaller than one acre in size and separated from each other by less than 100 feet (on average), the DOE mosaic methodology shall be used to determine the wetland category. The area of the wetlands must be greater than 50 percent of the total combined area of wetland and upland for the patchwork to be categorized as one wetland. The boundary of the mosaic wetlands must reflect the ecological interconnectedness of the wetlands within the mosaic. The County will not accept mosaic boundaries drawn to minimize the area of wetland within the mosaic. (See Figure 18E.30-1 in Chapter 18E.120 PCC.)
(Ord. 2012-2s § 6 (part), 2012; Ord. 2006-103s § 2 (part), 2006; Ord. 2004-56s § 4 (part), 2004)
1. The Critical Areas Atlas – County Wetland Inventory Maps provides an indication of where potential wetlands are located within the County. The actual presence or location of a potential wetland or a potential wetland that has not been mapped, but may be present on or adjacent to a site shall be determined using the procedures and criteria established in this Chapter.
2. The Department will complete a review of the Critical Areas Atlas – County Wetland Inventory Maps and other source documents for any proposed regulated activity to determine whether the project area for a proposed single-family dwelling unit or site for all other proposed regulated activities is located within a potential wetland. Identification of a potential wetland may also occur as a result of field investigations conducted by Department staff.
3. When the Department's maps, sources, or field investigation indicate that a potential wetland is located within 315 feet of the project area for a proposed one family dwelling unit or within 315 feet of the site for all other proposed regulated activities, the Department shall require a site evaluation (field investigation) to determine whether or not a regulated wetland is present and if so, its relative location in relation to the proposed project area or site. The findings of the site evaluation shall be documented as outlined in PCC 18E.30.030 B., C., D., or E. below.
4. If Department staff completes the site evaluation and determines that no regulated wetlands are present, then wetland review will be considered complete.
5. All site evaluations shall include a proposed categorization of the wetland in accordance with the guidelines set forth in PCC 18E.30.020 B. and a calculation of the standard wetland buffer as set forth in PCC 18E.30.060.
6. Unless otherwise stated in this Chapter, the critical area protective measure provisions contained in PCC 18E.10.080 shall apply.
B. General Wetland Review. General wetland review shall include the submittal of a wetland verification report or a wetland analysis report, together with a wetland application and fee. (See Figure 18E.30-2 in Chapter 18E.120 PCC.)
1. Wetland Verification Report.
a. A wetland verification report shall be submitted when the site evaluation determines that:
(1) No regulated wetland is present within 315 feet of the site;
(2) A regulated wetland is present, but its standard buffer does not extend within the site; or
(3) Wetlands are identified but are evaluated and found to be non-regulated as set forth in PCC 18E.20.030 K.
b. The wetland verification report shall include data sheets, site maps, and other field data and information necessary to confirm wetland presence or absence and category. If non-regulated wetlands (refer to PCC 18E.20.030 K.) are identified, a site plan must be provided that identifies their location.
c. The wetland verification report shall identify and discuss wetland boundaries within the site as well as those that extend offsite. Offsite wetlands and associated standard buffers do not have to be marked in the field.
d. Department staff shall review the wetland verification report and either:
(1) Accept the report and approve the wetland application; or
(2) Reject the report and require the submittal of a wetland analysis report.
2. Wetland Analysis Report.
a. If a regulated wetland or its standard buffer extends onto the site, the Department shall require a wetland analysis report. Information required in a wetland analysis report is identified in PCC 18E.30.070 – Appendix B.
b. If the Department determines that a Category I wetland is onsite which is associated with documented habitat for endangered, threatened, or sensitive species or for potentially extirpated plant species recognized by State or Federal agencies, the Department shall also require the submittal of a habitat assessment report as set forth in Chapter 18E.40 PCC.
c. If the Department determines that mitigation is necessary to offset the identified impacts, the applicant shall comply with the mitigation requirements set forth in PCC 18E.30.050.
d. Approval of the wetland application shall be granted upon a determination that the wetland analysis report and mitigation plan, if applicable, are thorough and accurate, and meet all requirements of this Title, and that the monitoring program and contingency plan are tied to an acceptable financial guarantee as set forth in PCC 18E.10.080 to assure that the requirements will be followed.
C. Single-family Dwelling Wetland Review. Two alternative review procedures exist for construction of one single-family dwelling and regulated activities accessory to a single-family dwelling. (See Figure 18E.30-3 in Chapter 18E.120 PCC.) Both review procedures require the completion of a site evaluation as follows:
1. Wetland Certification Process for Single-family Dwellings (No Encroachment into a Regulated Wetland or its Standard Buffer).
a. Prior to issuance of a building permit, site development permit, or on-site sewage system permit, the applicant shall submit a single-family wetland certification form completed by a wetland specialist that certifies either:
(1) No regulated wetlands are present within 315 feet of the project area; or
(2) Wetlands are present within 315 feet of the project area, but all regulated activities associated with the dwelling (i.e., landscaped areas, septic facilities, outbuildings, etc.) will occur outside of the standard buffer of the identified wetland.
b. If regulated wetland buffers extend onto the site and are within 315 feet of the project area, the wetland specialist shall place permanent, clearly visible, wetland buffer signs at the edge of the buffer. A wetland buffer sign affidavit, signed by the wetland specialist, shall be submitted to the Department as verification that the wetland buffer signs have been placed on the site.
c. A survey as outlined in PCC 18E.10.080 G. will not be required.
d. The single-family certification form may be used only to authorize single-family dwellings and associated homesite features such as one garage, driveways, gardens, fences, wells, lawns, and on-site septic systems. It may not be used for new agricultural activities, expansion of existing agricultural activities, forest practice activities, commercial projects, land divisions, buffer width modifications (as set forth in PCC 18E.30.060), or violations. The single-family form may not be used to make a claim for exemption under PCC 18E.20.030.
e. The single-family certification process will be monitored by the Department for accuracy, and enforcement actions will be initiated should encroachment into a regulated wetland or buffer occur.
f. The applicant/property owner assumes responsibility for any and all errors of the single-family certification form and all associated mitigation imposed by the Department.
g. Single-family certification forms shall be filed with the Pierce County Auditor's Office in accordance with PCC 18E.10.070 F. and 18E.10.110 B.
2. Single-family Wetland Application Process (Encroachment into the Standard Buffer of a Regulated Wetland).
a. A wetland application and wetland delineation report shall be submitted to the Department when the single-family dwelling and associated homesite features are located within the standard buffer of a regulated wetland.
b. The applicant may retain either a wetland specialist or Department staff to delineate the limits of a regulated wetland and determine the impacts associated with the project, subject to the following:
(1) A wetland delineation report, as defined in PCC 18E.30.030 C.3. below, shall be submitted to the Department for review; or
(2) Upon the applicant's request and payment of fees, the Department shall delineate the regulated wetland(s).
d. The applicant shall place permanent, clearly visible, wetland boundary buffer signs at the edge of the buffer.
e. A survey as defined in PCC 18E.10.080 G. will not be required.
3. Wetland Delineation Report. The wetland delineation report shall include data sheets; scaled site maps showing the project boundary, wetland boundary, categorization of the wetland and standard buffer boundary, boundary flag location and sample plot location and designation; a vicinity map with driving instructions; and any other field data and information necessary for the Department to confirm wetland presence, location, and category.
D. Agricultural Activity Wetland Review. A wetland application and wetland delineation report shall be submitted to the Department when the site evaluation indicates that a regulated wetland or its standard buffer extends into a site proposed for an agricultural activity.
1. The applicant may either retain a wetland specialist or Department staff to delineate the limits of a regulated wetland and determine the impacts associated with the project area, subject to the following:
a. A wetland delineation report, as defined in PCC 18E.30.030 C.3. above, shall be submitted to the Department for review; or
b. Upon the applicant's request and payment of fees, the Department shall delineate the regulated wetland(s).
2. If the Department determines that mitigation is necessary to offset the identified impacts, the applicant shall comply with the mitigation requirements set forth in PCC 18E.30.050.
3. The applicant shall place permanent, clearly visible, wetland boundary buffer signs at the edge of the buffer.
4. A survey as defined in PCC 18E.10.080 G. will not be required.
5. Agricultural activities may be initiated subject to compliance with the requirements set forth in PCC 18E.30.030 D.1. through 4. above and the submittal of a best management plan developed by the Pierce County Conservation District or Natural Resource Conservation Service (NRCS).
E. Forest Practice Wetland Review.
1. All forest practice activities regulated under Title 18H PCC, Development Regulations – Forest Practice Activities, that are not exempt from the provision of this Title shall be reviewed pursuant to the criteria set forth in PCC 18E.30.030 B., General Wetland Review, except for Conversion Option Harvest Plan (COHP).
2. An abbreviated wetland review process may be used for COHPs as follows:
a. A wetland application and verification report shall be submitted when a site evaluation determines that no regulated wetland is present within 315 feet of the area to be logged.
b. A wetland application and delineation report shall be submitted when a site evaluation determines that a regulated wetland or its buffer extends within 315 feet of the area to be logged. At a minimum the report shall include:
(1) A detailed description of all wetlands on or within 315 feet of the area to be logged, including the wetland(s) approximate size(s), vegetation, categorization, and hydrology source(s).
(2) Sample data sheets for each wetland.
(3) An accurate map delineating the boundaries of the wetland(s) and standard buffer(s) in relation to the boundaries of the site.
c. The wetland delineation report shall be prepared, signed, and dated by a wetland specialist.
d. The accuracy of the wetland delineation, flagging, and categorization shall be field verified by the Department.
3. Requests for deviation from the standard buffer requirements set forth in PCC 18E.30.060 A. will not be allowed as part of a forest practice application.
The following activities may be allowed within the standard buffer established pursuant to PCC 18E.30.060, when mitigated according to PCC 18E.30.50 A. and B.:
A. New construction of a single-family residence; or the reconstruction, remodeling, or maintenance of an existing single-family residence, within an existing lot of record subject to the following:
1. No more than one residential structure may be present within the lot.
2. Both the size of the proposed home and the character and intensity of development are consistent with the surrounding area or are of lesser intensity.
3. Impervious surface shall be limited to the minimum amount necessary to accommodate the proposed homesite and, where possible, surfaces such as driveways and patios shall be made of pervious materials.
4. The single-family residence must comply with applicable site development stormwater requirements.
5. Any well and necessary appurtenances, including a pump and appropriately sized pump house, but not including a water storage tank (unless the water storage tank can be contained within the pump house), must comply with the following conditions:
a. The pump house is a one-story building with a ground area of less than 120 square feet; and
b. The well is more than 75 feet deep; and
c. Access to the well and pump house shall be by a pervious trail for pedestrian traffic only or, if necessary, by an unimproved access for a maintenance vehicle.
6. Unless otherwise allowed by PCC 18E.30.040 B. or C., in no case shall the Department allow development within a buffer to occur closer to a wetland boundary than 75 percent of the buffer size as determined through use of PCC 18E.30.060 and Appendix F. An applicant who wishes to modify a buffer beyond these limits must pursue a variance as defined within PCC 18E.20.060.
7. The conversion from one family to multi-family use is prohibited.
B. The placement of utility lines which do not require excavation or utility pole installation in any part of a buffer for a Category II, III, or IV wetland. They may be placed in a buffer for a Category I wetland, provided that the minimum distance from the wetland edge is no less than 50 percent of the Category I buffer width established for the specific land use intensity type in the table in PCC 18E.30.060 A.
C. Within existing lots of record located in wildland areas, creation of a defensible space for protection against wildfire may be allowed in buffer areas located within 30 feet of dwellings, barns, and commercial-use buildings. These allowances do not apply to features such as swing sets, fences, dog houses, and other structures that can be easily relocated. The following defensible space activities may be allowed:
1. Tree limb removal. Where understory shrubs are present below the tree, removal shall follow the guidelines of PCC 18E.40.070 – Appendix E. Where understory shrubs are not present, tree limbs may be removed to a height of 10 feet above the ground;
2. Interruption of continuous shrub vegetation by selective thinning as defined within PCC 18E.40.070 – Appendix E;
3. Replacement of evergreen species with less flammable, native species as defined within PCC 18E.40.070 – Appendix E.
D. New farm and agricultural activities may be permitted within a buffer subject to the following:
1. Agricultural activities and structures shall comply with the provisions of Chapter 18E.70 PCC, Flood Hazard Areas.
2. The agricultural activity is in compliance with the USDA, NRCS Conservation Reserve Program farm management standards.
3. A copy of an approved NRCS or Pierce County Conservation District farm management plan that documents compliance with the USDA, NRCS Resource Management System Standards within the critical area has been submitted to the Department for review and approval.
E. Trimming of vegetation for purposes of providing view corridors will be allowed without a complete mitigation plan provided that trimming shall be limited to view corridors of a maximum 20-foot width and that benefits to fish and wildlife habitat are not reduced. Trimming shall be limited to hand pruning of branches and vegetation. Trimming shall not include felling, topping, or removal of trees. An applicant that wishes to remove trees or create a view corridor of larger size must complete review as set forth in PCC 18E.30.030 and 18E.30.060.
(Ord. 2009-18s3 §4 (part), 2009; Ord. 2006-103s § 2 (part), 2006; Ord. 2004-56s § 4 (part), 2004)
A. Mitigation. All regulated development activities in wetlands or buffers shall be mitigated according to this Title subject to the following order:
1. Avoiding the impact altogether by not taking a certain action or parts of actions;
2. Minimizing impacts by limiting the degree or magnitude of the action and its implementation by using appropriate technology or by taking affirmative steps to reduce impacts;
3. The following types of mitigation (in the following order of preference):
a. Rectifying the impact by repairing, rehabilitating, or restoring the affected environment;
b. Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action;
c. Compensating for the impact by replacing or providing substitute resources or environments. The purchase of credits from an in-lieu fee mitigation program (ILF program) or wetland mitigation bank may be an acceptable means of meeting this requirement for compensation (see Chapters 18G.20 and 18G.30 PCC);
4. Monitoring the impact and compensation and taking appropriate corrective measures; and
5. Mitigation for individual actions may include a combination of the above measures.
B. Mitigation for Regulated Activities in Wetland Buffers. Non-compensatory mitigation shall be required for all regulated activities in buffers. Specific mitigation plan requirements are provided in PCC 18E.30.070 – Appendix C. Approval of the mitigation plan shall be signified by a notarized memorandum of agreement signed by the applicant and Department Director or designee, and recorded with the Pierce County Auditor. The agreement shall refer to all requirements for the mitigation project.
C. Mitigation for Regulated Activities in Wetlands. Compensatory mitigation shall be required for regulated activities that result in the loss of wetland acreage. Non-compensatory mitigation shall be required for regulated activities that do not result in the loss of wetland acreage. Specific mitigation plan requirements are provided in PCC 18E.30.070 – Appendices D and E. Whenever compensatory mitigation is provided through an ILF program or wetland mitigation bank, an ILF use plan (PCC 18G.20.050 – Appendix A) is required in place of a compensatory mitigation plan.
1. The compensatory mitigation plan shall be completed in two phases, a conceptual phase and a detailed phase.
a. Conceptual phase. The applicant shall submit to the Department a conceptual mitigation plan for compensatory mitigation. Where environmental review is required, the Department shall not make a threshold determination prior to Department review and approval of the conceptual mitigation plan. See PCC 18E.30.070 – Appendix D for specific requirements of the conceptual mitigation plan.
b. Detailed phase. Following the Department's approval of the conceptual mitigation plan, the applicant shall submit a detailed mitigation plan for compensatory mitigation to the Department. See PCC 18E.30.070 – Appendix E for specific requirements of the detailed mitigation plan.
2. The detailed mitigation plan shall be prepared, signed, and dated by the wetland specialist to indicate that the plan is in accordance with specifications determined by the wetland specialist. A signed original mitigation plan shall be submitted to the Department.
3. Approval of the detailed mitigation plan shall be signified by a notarized memorandum of agreement signed by the applicant and Department Director or designee, and recorded with the Pierce County Auditor. The agreement shall refer to all requirements for the mitigation project.
4. The mitigation project shall be completed according to a schedule agreed upon between the Department and the applicant.
6. The wetland specialist shall be onsite during construction and plant installation phases of all mitigation projects.
7. On completion of construction for the wetland mitigation project, the wetland specialist shall submit an as-built report to the Department for review and approval.
D. Mitigation Banking. [Reserved]
(Ord. 2014-33 § 1 (part), 2014; Ord. 2004-56s § 4 (part), 2004)
A. Determining Buffer Widths. Buffer widths shall be measured horizontally from a perpendicular line established at the wetland edge based on the Base Buffer Width identified in Table 1 and adjustments in Appendix F:
Generalized Category of Wetland
Table 2. Land Use Impact "Intensity" Based on Development Types
Types of land uses that cause the impact based on common zoning categories
Commercial, Urban, Industrial, Institutional, Retail Sales, Residential with more than 1 unit/acre, New agriculture (high- intensity processing such as dairies, nurseries and green houses, raising and harvesting crops requiring annual tilling, raising and maintaining animals), High intensity recreation (golf courses, ball fields), hobby farms
Residential with 1unit/acre or less, Moderate-Intensity Open Space (parks), New agriculture (moderate-intensity such as orchards and hay fields)
Forestry, Open space (low-intensity such as passive recreation and natural resources preservation)
B. Modification of Buffer Widths. The standard buffer widths of PCC 18E.30.060 A. may be decreased through the averaging or reduction mechanisms of this Section. The standard buffer width may also be increased.
1. Standard Conditions. The buffer widths recommended for land uses with "high intensity" impacts to wetlands can be reduced to those recommended for "moderate intensity" impacts under the conditions identified below.
a. For wetlands that score moderate or high for habitat (20 points or more), the width of the buffer around the wetland can be reduced if both the following conditions are met:
(1) A relatively undisturbed native, vegetated corridor at least 100 feet wide is protected between the wetland and any other Priority Habitats as defined by the Washington State Department of Fish and Wildlife. The corridor must be protected for the entire distance between the wetland and the Priority Habitat via some type of legal protection such as a conservation easement; and
(2) Measures to minimize the impacts of different land uses on wetlands, as summarized in the following table, are applied.
Place activity that generates noise away from the wetland.
Route all new untreated runoff away from wetland,
Plant buffer with "impenetrable" natural vegetation appropriate for region
BMP's for dust
b. For wetlands that score less than 20 points for habitat, the buffer width can be reduced to those required for moderate land use impacts if measures to minimize the impacts of different land uses on wetland as summarized in the table above in PCC 18E.30.060 B.1.
2. Buffer Averaging. Buffer width averaging may be allowed only where the applicant demonstrates all of the following:
b. A habitat assessment has been submitted which demonstrates that no documented habitat for endangered, threatened, or sensitive fish, or animal species is present; or
c. For wetlands and/or required buffers associated with documented habitat for endangered, threatened, or sensitive fish, or wildlife species, a habitat assessment report has been submitted that demonstrates that the buffer modification will not result in an adverse impact to the species of study.
d. Width averaging will not adversely impact the wetland.
e. The total buffer area after averaging is no less than the buffer area prior to averaging. (See Figure 18E.30-4.)
f. The minimum buffer width will not be less than 75 percent of the widths established after the categorization is done and any buffer adjustments applied.
g. The averaging is accomplished within the project boundaries or through an off-site conservation easement or tract (or other acceptable protective mechanism) approved by the Department.
3. Buffer Increases. The Department may require increased buffer width(s) when any of the following are identified:
a. A larger buffer is necessary to maintain viable populations of existing species;
b. The wetland is used by, or associated with, species listed by the Federal government or the State as endangered, threatened, sensitive, or as documented priority species or habitats, or essential or outstanding potential sites such as heron rookeries or raptor nesting areas;
c. The adjacent land is susceptible to severe erosion and erosion control measures will not effectively prevent adverse wetland impacts;
d. The adjacent land has minimal vegetative cover or slopes greater than 20 percent.
C. If buffer width averaging is utilized and significant trees are identified on the outer edge of the reduced buffer such that their drip line extends beyond the buffer edge, the following tree protection requirements must be followed:
1. A tree protection area shall be designed to protect each tree or tree stand during site development and construction. Tree protection areas may vary widely in shape, but must extend a minimum of 5 feet beyond the existing tree canopy area along the outer edge of the dripline of the tree(s), unless otherwise approved by the Department.
2. Tree protection areas shall be added and clearly labeled on all applicable site development and construction drawings, submitted to the Department.
3. Temporary construction fencing at least 30 inches tall shall be erected around the perimeter of the tree protection areas prior to the initiation of any clearing or grading. The fencing shall be posted with signage clearly identifying the tree protection area. The fencing shall remain in place through site development and construction.
4. No clearing, grading, filling or other development activities shall occur within the tree protection area, except where approved in advance by the Department and shown on the approved plans for the proposal.
5. No vehicles, construction materials, fuel, or other materials shall be placed in tree protection areas. Movement of any vehicles within tree protection areas shall be prohibited.
6. No nails, rope, cable, signs, or fencing shall be attached to any tree proposed for retention.
7. The Department may approve the use of alternate tree protection techniques if an equal or greater level of protection will be provided.
(Ord. 2018-68s § 4 (part), 2018; Ord. 2004-56s § 4 (part), 2004)
D. Compensatory Mitigation Plan for Regulated Activities in Wetlands, Conceptual Phase.
E. Compensatory Mitigation Plan for Regulated Activities in Wetlands, Detailed Phase.
F. Wetland Buffer Widths.
18E.30.070 – Appendix A
Wetland categories shall be designated according to the following generalized criteria:
Category I wetlands are:
• Relatively undisturbed estuarine wetlands larger than 1 acre
• Wetlands that are identified by scientists of the Washington Natural Heritage Program/DNR as high quality wetlands
• Mature and Old growth forested wetlands larger than 1 acre
• Wetlands in coastal lagoons
• Wetlands that perform many functions well (wetlands scoring 70 points or more – out of 100) on the questions related to functions.
These wetlands are those that:
• represent a unique or rare wetland type; or
• are more sensitive to disturbance than most wetlands; or
• are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or
• provide a high level of functions.
Category II wetlands are:
• Estuarine wetlands smaller than 1 acre, or disturbed estuarine wetlands larger than 1 acre,
• A wetland identified by the state Department of Natural Resources as containing "sensitive" plant species,
• Wetlands with a moderately high level of functions (wetlands scoring between 51-69 points (out of 100) on the questions related to the functions
Category III wetlands are:
• wetlands with a moderate level of functions (scores between 30-50 points)
• Category IV wetlands have the lowest levels of functions (scores less than 30 points) and are often heavily disturbed.
The Category of a wetland shall not be changed to recognize illegal modifications to the wetland.
18E.30.070 – Appendix B
Information to be Included in a Wetland Analysis Report
A wetland analysis report shall include the following:
A. Vicinity map and detailed driving instructions to the site;
B. A site map setting forth all of the following:
1. Surveyed wetland boundaries based upon a delineation by a wetlands specialist (Note: this information may also be submitted in a digital format, which is designated as acceptable by the County);
2. Wetlands and buffers offsite, within 315 feet of the site boundaries, are also to be discussed and shown in as much detail as possible;
3. Site boundary property lines and roads;
5. Internal property lines, rights-of-way, easements, etc.;
6. Existing physical features of the site including buildings, fences, and other structures, roads, parking lots, utilities, water bodies, etc.;
7. Contours at the smallest readily available intervals, preferably at 2-foot intervals;
8. Hydrologic mapping showing patterns of surface water movement and known subsurface water movement into, through, and out of the site area; and
9. Location of all test holes and vegetation sample sites, and wetland boundary flags numbered to correspond with flagging in the field and field data sheets.
C. A report which includes the following:
1. Location information (legal description, parcel number, and address);
2. Delineation analysis results. The wetland boundaries on the site established by the delineation shall be staked and flagged in the field. If the wetland extends outside the site, the delineation report shall discuss all wetland areas within 300 feet of the site, but need only delineate those wetland boundaries within the site;
3. General site conditions including topography, acreage, and surface areas of all wetlands identified in the Pierce County Wetland Atlas and water bodies within one-quarter mile of the subject wetland(s);
4. Hydrological analysis, including topography of existing surface and known significant sub-surface flows into and out of the subject wetland(s); and
5. Discussion of the values of existing wetlands, including vegetative, faunal, and hydrologic conditions and the presence of threatened, endangered, candidate, sensitive or monitor species;
E. A summary of the proposed activity and potential direct or indirect impacts to the wetland(s) including stormwater-related impacts to wetland hydrology;
F. Recommended wetland category, including rationale for the recommendation;
G. Recommended buffer boundaries, including rationale for boundary locations;
H. Proposed on-site residential density transfer from wetlands and/or buffers to upland areas;
I. Site plan of proposed activity, including location of all parcels, tracts, easements, roads, structures, and other modifications to the existing site. The location of all wetlands and buffers shall be identified on the site plan.
J. The wetland analysis report shall be signed and dated by the wetland specialist.
18E.30.070 – Appendix C
Mitigation Plan for Regulated Activities in Buffers
A. A mitigation plan for regulated activities in buffers shall be prepared, signed, and dated by a wetland specialist and shall contain the following:
1. General goals of the mitigation plan including a discussion of the function and values of impact and enhancement areas;
2. Approximated site topography before and after alteration;
3. Location of proposed mitigation area (include a north arrow and scale);
4. General hydrologic patterns on the site before and after construction;
5. General plant selection and justification, planting instructions, and approximate planting sequencing and schedule;
6. A maintenance plan;
7. A monitoring and contingency plan. Monitoring is to occur a minimum of three years.
8. Estimated costs for the installation, maintenance, and monitoring phases of the project. Separate estimates shall be prepared for the installation phase and monitoring and maintenance phase of the project; and
9. Address and phone number of person or organization responsible for monitoring requirements.
B. Upon Department review and approval of this plan, it shall become the detailed plan.
18E.30.070 – Appendix D
Compensatory Mitigation Plan for
Regulated Activities in Wetlands – Conceptual Phase
A. The conceptual phase of a mitigation plan for regulated activities in wetlands shall be prepared, signed, and dated by a wetland specialist and shall include the following:
1. General goals of the compensatory mitigation plan, including an overall goal of no net loss of wetland function, value, and acreage;
2. Mitigation projects that involve Category I wetlands associated with documented habitat for endangered or threatened plant, fish, or animal species or for potentially extirpated plant species recognized by State or Federal agencies must also demonstrate a net benefit to the conservation of the affected species;
3. Site topography before and after construction;
4. Location of proposed wetland mitigation area;
5. General hydrologic patterns on the site before and after construction;
6. Field data confirming the presence of adequate hydrology to support the existing and created wetland area(s). At a minimum, the following information shall be included:
a. Seasonal (growing season) water level;
b. Sources of water (if the water source is adjacent to a stream or river then no instream structures will be allowed that restrict fish migration or access);
c. Pre- and post-development inflow and outflow volumes and velocity and frequency of flooding;
d. Groundwater and surface water table (from "Guidelines for Developing Freshwater Wetlands Mitigation Plans and Proposals," 1994, COE, EPA, DOE, USFWS, WDFW);
7. Nature of mitigation, including wetland types (in-kind and out-of-kind), general plant selection and justification, approximate project sequencing and schedule, and approximate size of the new wetland buffer. A discussion of the function and values of both the impact and creation areas is also to be provided;
8. A conceptual maintenance plan; and
9. Conceptual monitoring and contingency plan.
B. Once the Department approves the conceptual mitigation plan, a detailed mitigation plan shall be submitted. Due to the complex nature of creating and restoring wetlands, very detailed plans are needed (See PCC 18E.30.070 – Appendix E for further information on detailed mitigation plans).
18E.30.070 – Appendix E
Compensatory Mitigation Plan for Regulated
Activities in Wetlands – Detailed Phase
I. OUTLINE OF DETAILED MITIGATION PLAN
A. The detailed mitigation plan shall contain the following:
1. Site specific, quantifiable criteria for evaluating whether or not the goals for the proposed compensation are being met. Such criteria shall include the establishment of viable plant communities, hydric soil formation, and establishment of wetland hydrology, and may include water quality standards, species abundance and diversity targets, habitat diversity indices, or other ecological, geological, or hydrological criteria (see subsection III. below for specific performance standards).
2. Pre-development analysis of the proposed compensation area including:
a. Existing vegetation community analysis;
b. Hydrological analysis that demonstrates the project will not adversely impact existing wetland and buffer areas and that ensures adequate hydrology for any created wetland areas (see subsection V. for specific requirements);
c. Onsite soils analysis data and, where appropriate, Natural Resources Conservation Service Mapping;
d. Detailed description of flora and fauna existing on the site; and
e. Description of existing site conditions in relation to historic conditions for those sites which have been recently altered or degraded.
3. Proposed post-development conditions within existing wetland and buffer areas and mitigation areas, including:
a. Relationship of the project to the watershed and existing water bodies;
b. Topography, using 1-foot contour intervals;
c. Hydrologic analysis (see subsection V. for specific requirements);
d. Grading, filling, and excavation, including a description of imported soils;
e. Irrigation requirements;
f. Erosion control measures during construction; and
g. Areal coverage of planted areas to open water areas (if any open water is to be present.
4. Detailed site diagrams, to-scale construction drawings with cross-section data, topographic maps showing slope percentage and final grade elevations, and any other drawings appropriate to show construction techniques or anticipated final outcome. The plan shall provide for elevations which are appropriate for the desired habitat type(s). The construction drawings must include a note that requires the contractor to refer to the approved mitigation plan.
5. Planting plan prepared by a wetland specialist that shall include the following:
a. Soils and substrate characteristics;
b. Specification of substrate stockpiling techniques;
c. Planting instructions, including species, stock type and size, density or spacing of plants, and water and nutrient requirements; and
d. Specification of where plant materials will be procured. Documentation shall be provided which guarantees plant materials are to be procured from licensed regional nurseries or from wetlands on site which are part of the mitigation plan.
6. Schedule showing dates for beginning and completing the mitigation project, including a sequence of construction activities.
7. Monitoring and maintenance plan which includes the following:
a. Specification of procedures for monitoring and site maintenance; and
b. Schedule for submitting monitoring reports.
8. Detailed contingency plan, consistent with subsection IV. below.
9. Detailed budget for implementing the mitigation plan, including construction, monitoring, maintenance, and contingency phases.
10. Financial guarantee for the work to be performed as planned and approved. Separate guarantee estimates shall be prepared for the installation phase and monitoring and maintenance phase of the project.
11. Address and phone number of the person or organization responsible for monitoring requirements.
II. LOCATION CRITERIA
In cases in which it is determined that compensatory mitigation is appropriate, the following shall apply:
A. Compensatory mitigation shall be provided on-site, except where the applicant demonstrates that on-site mitigation is not scientifically feasible or practical due to physical features of the site.
B. When compensatory mitigation cannot be provided on-site, it shall be provided in the immediate vicinity of and within the same watershed as the regulated activity.
III. MITIGATION PERFORMANCE STANDARDS
A. When regulated activities occur in wetlands, the applicant shall restore, create, or enhance equivalent areas of wetlands. Equivalent areas shall be determined according to acreage, functional value, type, location, time factors, and projected success. No overall net losses shall occur in wetland acreage, functions and/or values, and any restored, created, or enhanced wetland shall be as persistent as the wetland it replaces.
B. When an applicant proposes to alter or eliminate wetland, the applicant shall replace acreage at the following ratios:
Category I: 6:1 (acreage replacement: acreage lost)
Category II: 3:1
Category III: 2:1
Category IV: 1.5:1
C. Ratios provided are for proposed projects with on-site, in-kind replacement which occurs prior to regulated activities on the site. The Department may increase the ratios under the following circumstances:
1. Uncertainty as to the probable success of the proposed restoration or creation; or
2. Significant period of time between destruction and replication of wetland functions; or
3. Projected losses in wetland functions and value; or
4. Off-site and/or out-of-kind compensation.
D. The Department may allow enhancement of existing or created wetland area(s) as a means of reducing the standard acreage replacement ratio if the applicant demonstrates that no net loss of wetland function or value will result provided that:
1. Enhancement mitigation ratios shall be no less than twice the standard creation ratio of the impacted wetland.
2. The applicant may be required to complete an analysis of the impact and mitigation areas in support of the acreage replacement ratio reduction. An example of an acceptable analysis methodology is the Washington State Department of Ecology Wetland Function Assessment Methodology (Ecology Publication # 99-116); however, other methodologies may be proposed.
3. The County will not allow the acreage replacement ratio to be reduced to less than 1:1 except as described in III-E below.
E. In the case of Category II, III, and IV wetlands, the replacement ratio may be decreased to a ratio of less than 1:1 if, following a public hearing, the Hearing Examiner determines the following:
1. A replacement ratio of greater than 1:1 is either not feasible on-site or would be likely to result in substantial degradation of other natural features; and
2. The mitigation plan shows that a net increase in wetland functional values will result from the mitigation; and
3. The mitigation is completed, and then monitored by the Department for one year prior to the issuance of permits. If after one year of monitoring, the Department is not satisfied that the anticipated final outcome of the mitigation plan will be met, modifications to the mitigation plan and further monitoring may be required. When the Department is satisfied that the mitigation will be successful, permits pending will be issued.
F. In-kind compensation shall be provided except where the applicant demonstrates that:
1. Greater functional and habitat values can be achieved through out-of-kind mitigation; and
2. The wetland system is already significantly degraded; or
3. Problems such as the presence of exotic vegetation and changes in watershed hydrology make implementation of in-kind compensation infeasible; or
4. Out-of-kind replacement will best meet identified regional goals (e.g., replacement of historically diminished wetland types).
G. Design requirements for the mitigation plan shall, at a minimum, include the following:
1. Use only native plants indigenous to Pierce County (not introduced or exotic species);
2. Use plants appropriate to the depth of water at which they will be planted;
3. Use plants that originate and are available from local sources;
4. Use plant species high in food and cover value for fish and wildlife;
5. Plant mostly perennial species;
6. Avoid committing significant areas of site to species that have questionable potential for successful establishment;
7. Water depth is not to exceed 6.5 feet (2 meters);
8. The grade or slope that water flows through the wetland is not to exceed 6 percent;
9. Slopes within the wetland and buffer should not be steeper than 3:1 (horizontal to vertical);
10. Planting densities and placement of plants shall be shown on the design plans;
11. The wetland should not contain more than 60 percent open water as measured at the seasonal high water mark;
12. Stockpiling shall be confined to upland areas and contract specifications should limit stockpile durations to less than four weeks. Erosion control measures shall be in effect at the stockpiling location;
13. Planting instructions shall describe proper placement, diversity, and spacing of seeds, tubers, bulbs, rhizomes, sprigs, plugs, cuttings, and transplanted stock;
14. Apply controlled release fertilizer at the time of planting and afterward only as plant conditions warrant (determined during the monitoring process), and only to the extent that the release would be conducted in an environmentally sound manner;
15. Install an irrigation system, as necessary, until plants are established.
H. Mitigation projects are unique and performance standards will differ based upon the goals and objectives of the project. However, performance standards pertaining to water regime, vegetative structure and establishment, and hydric soil formation are to be established for all mitigation projects, as defined below:
1. The mitigation wetland must meet the technical criteria for wetland hydrology, seasonal inundation, and/or saturation to the surface for a consecutive number of days greater than or equal to 12.5 percent of the growing season. Areas that are seasonally inundated and/or saturated to the surface for a consecutive number of days between 5 percent and 12.5 percent of the growing season may also be wetlands. Hydrology may be monitored through the use of one or a combination of the following: groundwater wells, piezometers, crest gauges, hand-dug soil pits, staff gauges, and continuous recording flow meters.
2. At a minimum, vegetative success equals the establishment of a multi-species, mixed canopy community comprised of emergent, scrub-shrub, and tree species. Yearly standards pertaining to survival and aerial coverage shall also be established for each vegetative stratum.
3. Hydric soil characteristics shall be monitored through the use of one or a combination of the following: Munsell soil color, pH, particle size, redox potential, organic content, microbial activity, time and duration of saturation or ponding, and alkalinity.
IV. MONITORING PROGRAM AND CONTINGENCY PLAN
A. A contingency plan shall be established for compensation in the event the mitigation project is inadequate or fails. The contingency plan is to provide specific corrective measures for such common mitigation plan failings as plant mortality, vandalism, damage due to wildlife grazing, grading errors, and hydro-regime problems. A financial guarantee on a form acceptable to the County is required for the duration of the monitoring period, and the guarantee plus any accrued interest will be released by the County when the required mitigation and monitoring are completed. To determine the amount of the financial guarantee, an estimate shall be submitted to the County detailing the work to be accomplished and the cost thereof. The estimate shall be based on current costs. The County will review the estimate and, if acceptable, will establish the financial guarantee at 125 percent of the estimate to allow for inflation and administration expenses should the County have to complete the project.
B. Requirements of the monitoring program are as follows:
1. Scientific procedures are to be used for establishing the success or failure of the project.
2. Monitoring reports prepared by a wetland specialist are to be submitted for Department review. Monitoring reports shall include discussions of wildlife utilization of the site, vegetation establishment, water quality, water flow, stormwater storage and conveyance, and existing or potential degradation, according to the following schedule:
a. At completion of construction of mitigation project (as-built report);
b. Thirty days after completion;
c. Early in the first growing season after construction;
d. End of the first growing season after construction;
e. Twice the second year; and
f. Annually after the second year.
3. Monitor for a period of time appropriate to the nature of the project (single-family versus commercial) and the complexity of the mitigation project. The majority of monitoring programs will last a minimum of five years.
4. The County will require a Right of Entry Form, as set forth in PCC 18E.10.140 – Appendix C, be recorded that allows County staff access to the mitigation area through completion of the monitoring program.
5. Correct for failures in the mitigation project.
6. Replace dead or undesirable vegetation with appropriate plantings.
7. Repair damages caused by erosion, settling, or other geomorphological processes.
8. If necessary, redesign mitigation project and implement the new design.
9. Correction procedures shall be approved by a wetland specialist and the Department Director or designee.
V. HYDROLOGY MONITORING GUIDELINES
A. Applicants are required to ensure that the proposed development does not result in adverse impacts to regulated wetland and/or buffers. To achieve this, an applicant must demonstrate the project will not adversely affect the wetland hydroperiod. To determine existing hydroperiod, use one of the following methods, listed in order of preference:
1. For Category I, II, III, and forested Category IV wetlands:
a. Estimation by a continuous simulation computer model. The model should be calibrated with at least one year of data taken using a continuously recording level gage under existing conditions and should be run for the historical rainfall period. Acceptable computer models include HSPF, KCRTS, or Department of Ecology WWHM. The resulting data can be used to express the magnitudes of depth fluctuation, as well as the frequencies and durations of surpassing given depths.
b. Measurement during a series of time intervals (no longer than one month in length) over a period of at least one year of the maximum water stage, using a crest stage gage, and instantaneous water stage, using a staff gage.
(1) The resulting data can be used to express water level fluctuation (WLF) during the interval as follows:
Average base stage = (instantaneous stage at beginning of interval + instantaneous stage at end of interval)/2
WLF = Crest stage – Average base stage
(2) Compute mean annual and mean monthly WLF as the arithmetic averages for each year and month for which data are available.
2. For scrub-shrub and emergent Category IV wetlands a single-event model may be used to ensure that there is no change in the volume of water delivered to the wetland under post-development conditions.
B. To forecast future hydroperiod, complete an estimation by the continuous simulation computer model calibrated during pre-development analysis and run for the historical rainfall period. The resulting data can be used to express the magnitudes of depth fluctuation, as well as the frequencies and durations of surpassing given depths. [Note: Post-development modeling results should generally be compared with pre-development modeling results, rather than directly with field measurements, because different sets of assumptions underlie modeling and monitoring. Making pre- and post-development comparisons on the basis of common assumptions allows cancellation of errors inherent in the assumptions.]
C. A hydroperiod analysis is to be used to ensure that the following hydroperiod limits are met:
1. Mean annual WLF (and mean monthly WLF for every month of the year) does not exceed 20 cm. Vegetation species richness decrease is likely with: (1) a mean annual (and mean monthly) WLF increase of more than 5 cm (2 inches or 0.16 feet) if pre-development mean annual (and mean monthly) WLF is greater than 15 cm, or (2) a mean annual (and mean monthly) WLF increase to 20 cm or more if pre-development mean annual (and mean monthly) WLF is 15 cm or less.
2. The frequency of stage excursions of 15 cm above or below pre-development stage does not exceed an annual average of six.
3. The duration of stage excursions of 15 cm above or below pre-development stage does not exceed 72 hours per excursion.
4. The total dry period (when pools dry down to the soil surface everywhere in the wetland) does not increase or decrease by more than two weeks in any year.
5. The following hydroperiod limits characterize wetlands inhabited by native amphibians listed as regulated wildlife species in PCC 18E.40.020 and apply to breeding zones during the time period of February 1 through May 31. (Note: If these limits are exceeded, then amphibian breeding success is likely to decline.)
a. The magnitude of stage excursions above or below the pre-development stage does not exceed 8 cm, and the total duration of these excursions does not exceed 24 hours in any 30-day period.
b. To apply this guideline a continuous simulation computer model needs to be employed. The model should be calibrated with data taken under existing conditions at the wetland being analyzed and then used to forecast post-development magnitude and duration of excursions.
18E.30.070 – Appendix F
Width of Buffers by Category of Wetland
Table 1. Width of Buffers Needed to Protect Category IV Wetlands
Buffer Width Adjustment to 25 feet base width (based on impact of land use)
Score for functions < 30 points
Low – No change
Moderate – No change
High – Increase by 25 feet
Table 2: Width of Buffers Needed to Protect Category III Wetlands
Buffer Widths Adjustments to 50 feet base width (by impact of land use)
Moderate level of function for habitat (score for habitat is 20 – 28 pts.)
Low – Increase by 25 feet
Moderate – Increase by 60 feet
High – Increase by 100 feet
Low – Decrease by 10 feet
High – Increase by 30 feet
Table 3: Width of Buffers Needed to Protect Category II Wetlands
Buffer Widths Adjustments to 100 feet base width (by impact of land use/apply most protective)
High level of function for habitat (score for habitat is 29-36 pts.)
Low – Increase by 50 feet
Moderate – Increase by 125 feet
High – Increase by 200 feet
Maintain connectivity to fish and wildlife species and ha 18E.40 areas
Low – Decrease by 25 feet
Moderate – Increase by10 feet
High – Increase by 50 feet
High level of function for water quality improvement and low for habitat (score water quality is 24-32 pts and habitat is less than 20)
Low – Decrease by 50 feet
Moderate – Decrease by 25 feet
High – No change
No additional discharges of untreated runoff
Moderate – Increase by 10 feet
Category II not meeting above criteria
Table 4: Width of Buffers Needed to Protect Category I Wetlands
Buffer Widths Adjustments to 150 feet base width (by impacts of land use/apply most protective)
Moderate – Increase by 40 feet
No additional discharges of surface water.
No septic systems within 300 feet
No additional surface discharges
Buffer size to be based on score for habitat functions or water quality functions
If forested wetland scores high for habitat need to maintain connectivity to other natural areas
Moderate – Increase by 75 feet
High – Increase by 150 feet
Maintain connectivity to other natural areas
Moderate level of function for habitat (score for habitat is 20-28 pts.)
Low – Decrease by 75 feet
Moderate – Decrease by 40 feet
High level of function for water quality improvement (score for WQI is 24-32) and low for habitat (score for habitat is less than 20 points)
Low – Decrease by 100 feet
Moderate – Decrease by 75 feet
High – Decrease by 50 feet
Category I wetlands not meeting any of the above criteria
NOTE: If the wetland meets more than one of the criteria listed in each table, the buffer needed to protect the wetland is the widest one.