Chapter 17.52B
WETLAND REGULATIONS
Sections:
17.52B.010 Purpose and intent of wetland regulations.
17.52B.020 Applicability of wetland provisions.
17.52B.030 Regulated activities.
17.52B.040 Exemptions.
17.52B.070 Wetland inventory maps.
17.52B.080 Wetland permit process and application requirements.
17.52B.090 Wetland rating and classification.
17.52B.100 Buffer areas.
17.52B.110 Density calculations for wetland areas.
17.52B.120 Wetland alteration and mitigation.
17.52B.130 Mitigation standards and criteria.
17.52B.140 Mitigation plan requirements.
17.52B.150 Monitoring program and contingency plan.
17.52B.160 Procedural provisions.
17.52B.010 Purpose and intent of wetland regulations.
A. The city finds that wetlands perform many important biological and physical functions that benefit the city and its residents, including but not limited to: helping to maintain water quality; storing and conveying stormwater and floodwater; recharging groundwater; providing important fish and wildlife habitat; and serving as areas for recreation, education and scientific study and aesthetic appreciation. Protection of wetlands is, therefore, necessary to protect public health, safety, and general welfare.
B. This chapter contains standards to manage development in association with the city’s wetland resources and enhance and restore wetlands where possible. The intent of these regulations is to avoid and minimize wetland impacts where avoidance and minimization is feasible and reasonable. In appropriate circumstances, impacts to wetlands resulting from regulated activities may be compensated for, consistent with this chapter. The city’s overall goal is to achieve no net loss of wetland function and value, and net acreage may be considered in achieving the overall goal.
C. It is the intent of this chapter to implement the goals and policies of the city comprehensive plan, including those pertaining to natural features and environmental protection; aesthetics and community character; opportunities for economic development; creating a balanced transportation system; ensuring adequate public facilities; and achieving a mix of land use types and densities consistent with the city’s land use plan.
D. It is the further intent of this chapter to establish special standards for the protection of wetlands and potential habitat of anadromous fish in compliance with the Washington Growth Management Act of 1990 (Chapter 36.70A RCW and its amendments and WAC 365-195-900 through 365-195-925) and best available science requirements. (Ord. 1112 § 13 (part), 2005)
17.52B.020 Applicability of wetland provisions.
A. The wetland management provisions of this chapter apply to any regulated activity (Section 17.52B.030) potentially affecting a wetland or its buffer unless otherwise exempt under Section 17.52B.040.
B. To avoid overlap and duplication, all city permit applications leading to the development or alteration of land, including but not limited to applications for: clearing and grading; subdivision or short subdivision, building permit, planned unit development; shoreline substantial development; variance and conditional use, shall be subject to and coordinated with the wetland requirements of this chapter and the Mukilteo Zoning Code, Chapter 17.13, Project Permit Review Process.
C. Nonproject actions, including but not limited to rezones, annexations, and adoption of plans and programs, shall be required to comply with the Growth Management Act (GMA), Chapter 36.70A RCW, including submittal of appropriate wetland information as determined by the city according to this chapter.
D. This chapter shall apply as any other overlay to development or land use regulations established by the city. In the event of a conflict between regulations in this chapter and any other city code, the regulation, which provide greater protection to environmentally sensitive areas shall apply. (Ord. 1112 § 13 (part), 2005)
17.52B.030 Regulated activities.
The following activities associated with any land use development proposal that occurs within a wetland and/or its buffer, or outside a wetland or buffer but potentially affecting the wetland or buffer, shall be regulated pursuant to the standards of this chapter:
A. Removing, excavating, disturbing or dredging soil, sand, gravel, minerals, organic matter or materials of any kind;
B. Dumping, discharging or filling any material;
C. Draining, flooding or disturbing the water level or water table;
D. Alteration, construction, reconstruction, or demolition of any structure or infrastructure, including driving pilings or placing obstructions;
E. Destroying or altering wetland vegetation through clearing, harvesting, shading or planting vegetation that would alter the wetland or buffer character; provided, that these activities are not part of a forest practice governed under Chapter 76.09 RCW and its rules;
F. Activities that result in significant changes in water temperature, physical or chemical characteristics of the wetland or buffer, including water quantity and quality, soil flow, or natural contours;
G. Any other activity potentially affecting a wetland or wetland buffer not otherwise exempt from this chapter; and
H. Work to maintain wetlands intentionally created from nonwetland areas as mitigation for wetland impacts. (Ord. 1112 § 13 (part), 2005)
17.52B.040 Exemptions.
A. The following activities that occur within wetlands and their buffers shall be exempt from this chapter:
1. Work such as mowing, maintenance, cleaning, excavation, or repair/replacement of flow control structures of artificially created wetlands intentionally created from nonwetland sites, including but not limited to grass-lined swales, irrigation and drainage ditches, detention facilities, and landscaping features. In those cases where stormwater control structures or devices were previously permitted in regulated wetlands, the only exempt activity shall be allowed and it shall be limited to the minimum necessary to maintain the outlet or inlet structure. If the wetland requires additional work to maintain storage capacity as envisioned per the original permit approval, a report shall be prepared by a qualified wetland specialist as defined in Chapter 17.08 that analyzes the extent, type, and function of wetland to determine the extent of the regulated or exempt activity(ies).
2. Work in those wetlands created after July 1, 1990, that were unintentionally created as a result of road, street, or highway construction.
3. Maintenance, operation and reconstruction of existing roads, streets, railroad lines, utilities and associated structures undertaken pursuant to best management practices, provided activities shall not increase the impervious area by more than two hundred square feet and disturbed areas are restored to an acceptable usable condition as required by the public works and planning directors.
4. Normal maintenance, repair and reconstruction of private or publicly-owned structures undertaken pursuant to public works director approved best management practices; provided, that reconstruction of any structures shall not impact any Category I wetland or more than one thousand square feet of Category II wetlands, including their associated buffers, and shall not increase the structural footprint.
5. Site investigation work and studies necessary to prepare land use applications, including soils tests, water quality studies, wildlife studies and similar tests and investigations; provided, that any disturbance of the wetland shall be the minimum necessary to carry out the work or studies.
6. Education activities, scientific research, and outdoor recreational activities, including but not limited to, interpretive field trips, bird watching and hiking and associated interpretive signage that will not have a significant effect on the wetland.
7. Emergency activities that are required due to landslides, floods, earthquakes other acts of nature or emergency utility repairs that are necessary to prevent an immediate threat to public health, safety or property. A mitigation plan prepared in accordance with this chapter shall be submitted to the city within three months of the emergency activity and the approved mitigation shall be implemented within six months of the emergency repair.
8. Minor activities such as invasive plant management; snagging of dead, dying, or diseased vegetation; and removal of hazardous trees where owners’ property or adjacent properties, or the health and safety of the general public or employees are in danger of damage or where slope stabilization could be negatively affected that are determined by the city to have minimal impacts to wetlands and wetland buffers.
9. Construction of new utility facilities or improvements to existing utility facilities that take place within existing improved right-of-way or existing impervious surface that does not increase the amount of impervious surface, or the use of trenchless technology that would not disturb the wetland or wetland buffer such as boring, tunneling or jacking under a wetland.
B. No private or public entity shall undertake exempt activities as listed in this section prior to providing the city written notification of their intent to proceed with an exempt activity. The city shall verbally confirm the activity is exempt and where needed provide written authorization within thirty days of the receipt of the written notice.
C. In case of any question as to whether a particular activity is exempt from the wetland provisions of this chapter, the city’s determination shall prevail and shall be determinative.
D. Notwithstanding the exemptions provided by this subsection, any otherwise exempt activity impacting a wetland and buffer should meet the purpose and intent of this chapter and should consider on-site alternatives that avoid or minimize impacts. (Ord. 1112 § 13 (part), 2005)
17.52B.070 Wetland inventory maps.
A. The city shall maintain wetland maps showing the approximate location and extent of wetlands within city jurisdiction. These maps will only show wetlands identified to date, and shall be used only as a general guide to assist property owners. The location and extent of wetlands are determined on a lot-by-lot, project-by-project basis, and if a wetland is not shown on the inventory map, that does not necessarily mean wetlands do not occur on the lot. The city will update the wetland inventory map as wetlands are mapped in the field and submitted by applicants to the city.
B. The wetland boundary and type shall be determined by a qualified wetland specialist according to the wetland delineation procedures as defined in the definitions, Chapter 17.08. In the event of any conflict between the wetland location or designation shown on the city’s map and the location or designation as determined in the field by a qualified wetland specialist using the defined wetland delineation procedures, the field determination shall control. (Ord. 1112 § 13 (part), 2005)
17.52B.080 Wetland permit process and application requirements.
A. Preapplication Conference. All applicants are encouraged to meet with the city prior to submitting an application subject to the wetland provisions of this chapter. The purpose of this meeting shall be to discuss the wetland requirements, process and procedures; to review the critical areas checklist and any conceptual plans prepared by the applicant; to identify potential wetlands impacts and mitigation measures; and to familiarize the applicant with state and federal wetland programs. Such conference shall be for the convenience of the applicant and any recommendations shall not be binding on the applicant or the city.
B. Wetland Delineation Report. If the city determines that wetland or buffer impacts might occur as a result of the proposal, a wetland delineation report, as defined in Chapter 17.08, must be submitted to the city for review prior to the issuance of a development permit pursuant to Chapter 17.13, Project Permit Review Process. The report must be prepared in accordance with City permit application requirements pursuant to Chapter 17.13 and incorporate best available science as defined in Chapter 17.08. The report will analyze the extent, type, and function of wetlands and buffers on any site where regulated or exempt activities are proposed. The report will also be used by the city to determine the appropriate wetland type and buffer requirement for the wetland, and to assist the city in determining appropriate mitigation if required.
C. Wetland Specialist. A qualified wetland specialist as defined in Chapter 17.08 shall prepare all reports and studies required of the applicant by this chapter. The city may retain a qualified wetland specialist, at the expense of the applicant, to review and confirm the applicant’s reports, studies, and plans.
D. This section is not intended to create a separate wetland permit process for development proposals. To the extent possible, and pursuant to Chapter 17.13, the city shall consolidate and integrate the review and processing of wetland-related aspects of proposals with other land use and environmental considerations and approvals. (Ord. 1112 § 13 (part), 2005)
17.52B.090 Wetland rating and classification.
A. Classification. Wetlands shall be classified as Category I, II, III or IV using the Washington State Department of Ecology’s Wetland Rating System for Western Washington, Publication #04-06-025, or as amended hereafter. Wetland delineations shall be determined by using the Washington State Wetlands Identification and Delineation Manual, March 1997, or as amended hereafter.
B. Sources used to identify designated wetlands include, but are not limited to:
1. United States Department of the Interior, Fish and Wildlife Service, National Wetlands Inventory.
2. Areas identified as hydric soils, soils with significant soil inclusions and “wet spots” within the United States Department of Agriculture/Soil Conservation Service Soil Survey for Snohomish County.
3. Washington State Department of Natural Resources, Geographic Information System: Hydrography and Soils Survey Layers.
4. City of Mukilteo critical areas inventory maps. (Ord. 1112 § 13 (part), 2005)
17.52B.100 Buffer areas.
A. The establishment of wetland buffer areas shall be required for all development proposals and activities adjacent to wetlands to protect the functions and integrity of the wetland. Buffers between regulated activities and wetlands help stabilize soil and prevent erosion, filter suspended solids and nutrients and harmful toxic substances, moderate effects of stormwater runoff, support and protect plant and animal species and habitats, enhance plant and wildlife diversity, and discourage adverse human effects in the wetland.
B. The buffer shall be measured from the upland edge of the wetland as delineated using wetland delineation methods defined in Chapter 17.08.
C. Buffers are not intended to be established or to function independently of the wetland; they are established to protect.
D. The establishment of a buffer or buffer mitigation shall not prevent a use or activity that would otherwise be permitted in the wetland or buffer as allowed in subsections H and I of this section.
E. Buffer Widths. Buffers shall be established using the “Buffer Alternative 3A” methodology contained in the Department of Ecology’s document titled “Freshwater Wetlands in Washington State, Volume 2: Managing and Protecting Wetlands, Appendix 8-C.” All buffer widths shall be measured from the wetland boundary as surveyed in the field. If according to the buffer mitigation plan, the buffer is not sufficient to protect the wetland, the city may require larger buffers where it is necessary to protect wetland functions based on site-specific characteristics. Buffer Alternative 3A establishes buffer widths based on graduated-scale habitat point value for wetlands.
|
Cat I |
Cat I-III |
|||||||||
|
Wetland Types or Points for Habitat |
NHW |
Bogs |
E & L |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
|
High Intensity |
250 |
250 |
200 |
100 |
100 |
120 |
140 |
160 |
180 |
200 |
|
Moderate Intensity |
190 |
190 |
150 |
75 |
75 |
90 |
105 |
120 |
135 |
150 |
|
Cat I-III |
Cat I & II |
Cat III |
Cat III |
Cat IV |
|||||
|
Wetland Types or Points for Habitat |
27 |
28 |
29 |
30 |
≥31 |
WC 24-32 & Hab. <20 |
Inter-dunal |
£20 |
£30 |
|
High Intensity |
220 |
240 |
260 |
280 |
300 |
100 |
150 |
80 |
50 |
|
Moderate Intensity |
165 |
180 |
195 |
210 |
225 |
75 |
110 |
60 |
40 |
WC = Water Quality Score
NHW = Natural Heritage Wetland
E & L = Estuarine and Lagoons
Forested Wetlands = Buffer is based on habitat score
None = Wetlands which do not meet any of the other listed types
Where:
|
Impact Level |
Adjacent Land Uses |
|
High |
Commercial, urban, industrial, institutional, retail sales, residential greater than one unit/acre, high-intensity agriculture (dairies, nurseries, greenhouses, etc.), high-intensity recreation (golf courses, ball field, etc.), and hobby farms. |
|
Moderate |
Residential less than one unit/acre, open space (parks with biking or jogging trails), moderate-intensity agriculture (orchards, hay field, etc.), paved trails, logging roads, utility corridor or right-of-way shared by several utilities including access roads. |
Figure 1: Wetland Buffers
F. Buffer Measurement. Buffers shall be established using the “Buffer Alternative 3A” methodology contained in the Department of Ecology’s document titled “Freshwater Wetlands in Washington State, Volume 2: Managing and Protecting Wetlands, Appendix 8-C.” All buffer widths shall be measured from the wetland boundary as surveyed in the field. If according to the buffer mitigation plan, the buffer is not sufficient to protect the wetland, the city may require larger buffers where it is necessary to protect wetland functions based on site-specific characteristics. Buffer Alternative 3A establishes buffer widths based on wetland category, intensity of impacts, and wetland functions or special characteristics.
G. Buffering Averaging. The widths of buffers may be averaged if this will improve the protection of wetland functions or if it is the only way to allow for reasonable use of a parcel. There is no scientific information available to determine if averaging the widths of buffers actually protects wetland functions, therefore averaging shall only be allowed in the below-listed situations. Averaging may be used in conjunction with any of the other provisions for reduction in buffers.
1. Averaging to improve wetland protection may be permitted when all of the following conditions are met:
a. The wetland has significant differences in characteristics that affect its habitat functions, such as a wetland with a forested component adjacent to a degraded emergent component or a “dual-rated” wetland with a Category I area adjacent to a lower-rated area.
b. The buffer is increased adjacent to the higher-functioning area of habitat or more sensitive portion of the wetland and decreased adjacent to the lower-functioning or less sensitive portion.
c. The total area of the buffer averaging is equal to the area required without averaging.
d. The buffer at its narrowest point is never less than three-quarters of the required width.
2. Averaging to allow reasonable use of a parcel may be permitted when all of the following are met:
a. There are no feasible alternatives to the site design that could be accomplished without buffer averaging.
b. The averaged buffer will not result in degradation of the wetland’s functions and values as demonstrated by a report from a qualified wetland professional.
c. The total buffer areas after being averaged is equal to the area required without the averaging.
d. The buffer at its narrowest point is never less than three-quarters of the required buffer width.
H. Buffer Reduction. The buffer width may be reduced from high intensity levels to moderate intensity levels under the following conditions:
1. For wetland that scores moderate or high for habitat (twenty points or more for the habitat functions), the width of the buffer can be reduced if both of the following are met:
a. A relatively undisturbed, vegetated corridor at least one hundred feet wide is protected between the wetland and any other priority habitats as defined by the Washington State Department of Fish and Wildlife. Priority habitats in western Washington include: wetlands, riparian zones, aspen stands, cliffs, prairies, caves, stands of Oregon white oak, old-growth forests, estuary/estuary-like, marine/estuarine shorelines, eelgrass meadows, talus slopes, urban natural open space.
b. The corridor must be protected for the entire distance between the wetland and the priority habitat by some type of legal protection such as a conservation easement.
c. Measures to minimize the impacts of different land uses on wetlands shall be applied.
2. For wetlands that score less than twenty points for habitat, the buffer width can be reduced to that required for moderate land-use impacts by applying measures to minimize the impacts of the proposed land uses.
3. The following list of mitigation measures as referenced above shall be used to minimize impacts from proposed development on wetlands:
|
Disturbance |
Activities that Cause Disturbance |
Measures to Minimize Impacts |
|
Lights |
Parking lots, warehouses, manufacturing, residential |
Direct lights away from wetland. |
|
Noise |
Manufacturing, residential |
Locate activity that generates noise away from wetland. |
|
Toxic Runoff* |
Parking lots, roads, manufacturing, residential areas, application of agricultural pesticides, landscaping |
Route all new, untreated runoff away from wetland while ensuring wetland is not dewatered. Establish covenants limiting use of pesticides within 150 feet of wetland. Apply integrated pest management. |
|
Stormwater Runoff |
Parking lots, roads, manufacturing, residential areas, commercial, landscaping |
Retrofit stormwater detention and treatment for roads and existing adjacent development. |
|
Changes in Water Regime |
Impermeable surfaces, lawns, tilling |
Infiltrate or treat, detain, and disperse into buffer new runoff from impervious surfaces and new lawns. |
|
Pets and Human Disturbance |
Residential areas |
Use privacy fencing; plant dense vegetation to delineate buffer edge and to discourage disturbance using vegetation appropriate for ecoregion; place wetland and its buffer in a separate tract. |
|
Dust |
Tilled fields |
Use best management practices to control dust. |
|
* These examples are not necessarily adequate for minimizing toxic runoff if threatened or endangered species are present at the site. |
||
I. The planning director may authorize the following low impact uses and activities within a wetland and wetland buffer upon showing that said uses or activities will be performed in a manner that will not adversely disturb the wetland, significantly increase the impervious surface of the buffer, or decrease the functions of the associated wetland: pedestrian trails, viewing platforms, interpretative signage, utility easements, and the boring of underground utilities pursuant to best management practices. Uses permitted within the buffer shall be located in the outer portion of the buffer as far as possible from the wetland.
J. Except where previously approved stormwater facilities were located in wetlands, all new stormwater management facilities, such as water quality swales, shall not be located within the required buffer unless no other locations are feasible and the location of such facilities will not have an adverse impact on the wetland. Stormwater detention ponds and outlet structures shall not be allowed in wetlands or their buffers.
K. Buffers shall be shown on the development site plans or final plat maps along with the notation requirements identified in Section 17.52.035, Native growth protection areas (NGPAs) and buffers.
L. If an existing property has a previously delineated and/or approved wetland and associated buffer approved by the city, the approved wetland buffer will remain in effect. Redevelopment, and/or additions outside of the existing footprint shall be subject to the previously approved buffer, however a buffer enhancement plan may be required in accordance with subsection F of this section if the wetland or buffer has become degraded or is currently not functioning or if the wetland and/or buffer maybe negatively affected by proposed new development.
M. Nonconforming Uses in Buffers. Where a legally established, nonconforming use of the buffer existing (e.g., a road or structure that lies within the width of a wetland buffer), proposed actions in the buffer may be permitted as long as they do not increase the degree of non-conformity. This means no increase in the impacts to the wetland from activities in the buffer. For example, if a land use with high impacts (e.g., building an urban road) is being proposed next to a Category II wetland with a moderate level of function for habitat, a one-hundred-fifty-foot buffer would be needed to protect function. If, however, an existing urban road is already present and only fifty feet from the edge of the Category II wetland, the additional one hundred feet of buffer may not be needed if the road is being widened. A vegetated buffer on the other side of the road would not help buffer the existing impacts to the wetland from the road. If the existing road is resurfaced or widened (e.g., to add a sidewalk) along the upland edge, without any further roadside development that would increase the degree of nonconforming, the additional buffer is not necessary. The associated increase in impervious surface from widening a road, however, may necessitate mitigation for impacts from stormwater. If, however, the proposal is to build a new development (e.g., shopping center or residential development) along the upland side of the road, the impacts to the wetland and its function may increase. This would increase the degree of nonconformity. The project proponent would need to provide the additional one hundred feet of buffer extending beyond the road or apply for buffer averaging.
N. Minor additions or alterations such as decks and small additions less than one hundred twenty square feet, interior remodels, or tenant improvements which have no impact on the wetland or wetland buffer are exempt from the buffer enhancement requirements. (Ord. 1147 § 1, 2005; Ord. 1112 § 13 (part), 2005)
17.52B.110 Density calculations for wetland areas.
A. An owner of a property containing wetlands may be permitted to transfer the density attributable to the wetland area to another nonwetland, nonsensitive portion of the same site or property, subject to the limitations of this section.
B. Up to one hundred percent of the density that could be achieved on the wetland and buffer portion of the site can be transferred to the non-wetland portion, subject to:
1. The density limitations of the underlying zoning classification;
2. The minimum lot size of the underlying zoning classification may be reduced to three thousand square feet in order to accommodate the transfers in densities;
3. Applicable setbacks may be reduced to fifteen feet, and the lot coverage standards of underlying zoning regulations may be increased to sixty percent;
4. The area to which density is transferred shall not be constrained by another environmentally critical area regulation. (Ord. 1112 § 13 (part), 2005)
17.52B.120 Wetland alteration and mitigation.
A. After careful consideration of the potential impacts and a determination that impacts are unavoidable, unavoidable impacts to wetlands not exempt under Section 17.52B.040 or meeting the criteria for a reasonable use exception in Section 17.52.025 shall be mitigated. Mitigation actions by an applicant shall occur in the following priority sequence:
1. Avoiding the impact altogether by not taking a certain action or parts of actions;
2. Minimizing impacts by limiting the degree of magnitude of the action and its implementation (e.g., use of appropriate technology, consideration of alternative site plans and building layouts and/or reductions in the density or scope of the proposal);
3. Rectifying the impact by repairing, rehabilitating or restoring the affected environment;
4. Reducing or eliminating the impact or hazard over time by preservation and maintenance operations during the life of the action;
5. Compensating for the impact by replacing, enhancing or otherwise providing equivalent or greater wetland functions;
6. Monitoring the impact and taking appropriate corrective measures.
B. Unless otherwise exempt, or an exception is granted by the city, alteration of wetlands and/or their buffers may be permitted by the city subject to the following criteria:
1. Category I Wetlands. Alterations of Category I wetlands shall be avoided, subject to the reasonable use provisions in Section 17.52.025.
2. Category II and III Wetlands. With respect to activities proposed in Category II and III wetlands, the following standards shall apply:
a. Water-dependent activities may be allowed where there are no practicable alternatives that would have a less adverse impact on the wetland, its buffer, and other critical areas.
b. Where nonwater-dependent activities are proposed, it shall be presumed that alternative locations are available, and activities and uses shall be prohibited, unless the applicant demonstrates that:
i. The basic project purpose cannot reasonably be accomplished and successfully avoided, or result in less adverse impact on a wetland on another site or sites in the general region; and
ii. All alternative designs of the project as proposed, that would avoid or result in less of an adverse impact on a wetland or its buffer, such as a reduction in the size, scope, configuration, or density of the project, are not feasible.
3. Category IV Wetlands. Activities and uses that result in unavoidable and necessary impacts may be permitted in Category IV wetlands and associated buffers in accordance with an approved critical area report and mitigation plan, and only if the proposed activity is the only reasonable alternative that will accomplish the applicant’s objective. Full mitigation for the acreage and lost functions will be provided under the requirements of this chapter.
C. Proposals which include less preferred and/or compensatory mitigation shall demonstrate that:
1. All feasible and reasonable measures will be taken to reduce impacts and losses to the wetlands, or to avoid impacts where avoidance is required by these regulations;
2. The restored, created, or enhanced wetland will be as available and persistent as the wetland it replaces;
3. No overall loss will occur in wetland area, function, or values;
4. The applicant has the financial resources and technical expertise to satisfactorily complete the project;
5. The applicant can demonstrate the capacity to monitor the site and make corrections during the monitoring period if the project fails to meet projected goals; and
6. The applicant can protect and manage, or provide for the protection and management of, the compensation area to avoid further development or degradation and to provide long-term persistence of the project area.
D. Owners of property with Category I through IV wetlands may also provide a comparable alternative mitigation plan which will result in equal or better wetland quality. (Ord. 1112 § 13 (part), 2005)
17.52B.130 Mitigation standards and criteria.
A. Location and Timing of Mitigation.
1. Restoration, creation, or enhancement actions should be undertaken on or adjacent to the site, or where restoration or enhancement of a former wetland is proposed, within the same watershed. Replacement in-kind of the impacted wetland is preferred for creation, restoration, or enhancement actions. The city may accept or recommend restoration, creation, or enhancement which is off-site and/or out-of-kind if the applicant can demonstrate that on-site or in-kind restoration, creation, or enhancement is infeasible due to constraints such as parcel size or wetland type, or that a wetland of a different type or location is justified based on regional needs or functions
2. Whether occurring on-site or off-site, the mitigation project shall occur near an adequate water supply (river, stream, and groundwater) with a source of hydrology to the wetland to ensure a successful development or restoration.
3. Any agreed upon mitigation plan shall be completed before initiation of other permitted activities, unless a phased or concurrent schedule has been approved by the city.
B. Wetland Mitigation Ratios.
1. Where wetland alterations are permitted by the city, the applicant shall restore, create, or enhance equivalent wetland area in order to compensate for wetland losses. Equivalent areas are determined according to wetland category, acreage, function, the length of time it takes for the restored or created wetland to approximate the characteristics of the original wetland, and the probability of success. Where feasible, applicants are encouraged to provide a higher type and quality of wetland than the altered wetland (based on the wetland rating system in Section 17.52B.090 of this chapter).
2. The following ratios shall be established as a starting point for further discussion with each proponent on a case by case compensatory mitigation analysis and plan. Ratios shall apply to creation or restoration that is in-kind, is on-site, is the same category, is timed prior to or concurrent with alteration, and has a high probability of success. These ratios do not apply to remedial actions resulting from unauthorized alterations; greater ratios shall apply in those cases as required by the permitting agency(ies).
|
Category and Type of Wetland |
Re-Establishment or Creation |
Rehabilitation |
Re-Establishment or Creation (R/C) and Enhancement (E) |
Enhancement Only |
|
Category I |
||||
|
Forested |
6:1 |
12:1 |
1:1 R/C and 10:1 E |
24:1 |
|
Based on Score for Functions |
4:1 |
8:1 |
1:1 R/C and 6:1 E |
16:1 |
|
Estuarine |
Case by Case |
6:1 rehabilitation of an estuarine wetland |
Case by Case |
Case by Case |
|
Bog |
Irreplaceable – Avoidance Required |
6:1 rehabilitation of a bog |
Case by Case |
Case by Case |
|
Coastal Lagoon |
Irreplaceable – Avoidance Required |
6:1 rehabilitation of a coast lagoon |
Case by Case |
Case by Case |
|
Natural Heritage |
Irreplaceable – Avoidance Required |
6:1 rehabilitation of a natural heritage site |
Case by Case |
Case by Case |
|
Category II |
||||
|
Estuarine |
Case by Case |
4:1 |
Case by Case |
Case by Case |
|
Interdunal |
2:1 Compensation has to be interdunal |
4:1 Compensation has to be interdunal |
1:1 R/C and 2:1 E |
8:1 |
|
All Other |
3:1 |
8:1 |
1:1 R/C and 4:1 E |
12:1 |
|
Category III |
2:1 |
4:1 |
1:1 R/C and 2:1 E |
8:1 |
|
Category IV |
1.5:1 |
3:1 |
1:1 R/C and 2:1 E |
6:1 |
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Creation = The manipulation of the physical, chemical, or biological characteristics present to develop a wetland on an upland or deepwater site, where a wetland did not previously exist. Activities typically involve excavation of upland soils to elevation that will produce a wetland hydroperiod, create hydric soils, and support the growth of hydrophytic plant species. Establishment results in a gain in wetland acres. Re-establishment = The manipulation of the physical, chemical, or biological characteristics of a site with the goal of returning natural or historic functions to a former wetland. Activities could include removing fill material, plugging ditches, or breaking drain tiles. Re-establishment results in a gain in wetland acres. Rehabilitation = The manipulation of the physical, chemical, or biological characteristics of a site with the goal of repairing natural or historic function of a degraded wetland. Activities could involve breaching a dike or reconnecting wetland to a floodplain or returning tidal influence to a wetland. Rehabilitation results in a gain in wetland function but does not result in a gain in wetland acres. Enhancement = The manipulation of the physical, chemical, or biological characteristics of a wetland site to heighten, intensify or improve functions or to change the growth stage or composition of the vegetation present. Enhancement is undertaken for specified purposes such as water quality improvement, flood water retention or habitat. Activities typically consist of planting vegetation, controlling nonnative or invasive species, modifying the site elevation or the proportion of open water to influence hydroperiods, or some combination of these. Enhancement results in a change in some wetland functions and can lead to a decline in other wetland function, but does not result in a gain in wetland acres. |
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C. Mitigation Banking. The use of a mitigation bank may be approved for use as a compensation for unavoidable impacts to wetland when:
1. The bank is certified under Chapter 173-700 WAC;
2. The planning director or his/her designee determines that the wetland mitigation bank provides appropriate mitigation for the authorized impacts;
3. The proposed use of credits is consistent with the terms and conditions of the bank’s certification;
4. Replacement ratios for projects using bank credits shall be consistent with replacement ratios specified in the bank’s certification;
5. Credits from a certified wetland mitigation bank may be used to mitigate for impacts located within the service area specified in the bank’s certification. In some cases, bank service areas may include portions of more than one adjacent drainage basin for specific wetland functions. (Ord. 1112 § 13 (part), 2005)
17.52B.140 Mitigation plan requirements.
A. Where it is determined by the city that compensatory wetland mitigation is required or appropriate, a qualified wetland specialist shall prepare a preliminary and final mitigation plan using best available science in accordance with city requirements for city review. The mitigation plan shall include:
1. Environmental Goals and Objectives. The plan shall include a written report identifying environmental goals and objectives of the compensation proposed and including:
a. A description of the anticipated impacts to the critical areas and the mitigating actions proposed and the purposes of the compensation measures, including the site selection criteria; identification of compensation goals; identification of resource functions; and dates for beginning and completion of site compensation construction activities. The goals and objectives shall be related to the functions and values of the impacted critical area;
b. A review of the best available science supporting the proposed mitigation and a description of the report author’s experience to date in restoring or creating the type of critical area proposed; and
c. An analysis of the likelihood of success of the compensation project.
2. Performance Standards. The mitigation plan shall include measurable specific criteria for evaluating whether or not the goals and objectives of the mitigation project have been successfully attained and whether or not the requirements of this chapter have been met.
3. Construction Plans. The mitigation plan shall include written specifications and descriptions of the mitigation proposed and shall include detailed site diagrams, scaled cross-sectional drawings, topographic maps showing slope percentage and final grade elevations, and any other drawings appropriate to show construction techniques. The written plan shall include:
a. The proposed construction sequencing, timing, and duration;
b. Grading and excavation details;
c. Erosion and sediment control features;
d. A planting plan specifying plant species, quantities, locations, size, spacing, and density; and
e. Measures to protect and maintain plants until established.
4. Contingency Plan. The mitigation plan shall include identification of potential courses of action, and any corrective measure to be taken if monitoring or evaluation indicated project performance standards are not being met.
B. The applicant’s qualified wetland specialist and the city must monitor installation of any construction to ensure mitigation is constructed or otherwise installed according to the approved mitigation plan requirements.
C. For those projects that are only required to provide buffer enhancement mitigation, an applicant may use the city’s conceptual buffer mitigation plan as a basis to prepare a buffer enhancement plan. The final plan must be approved by the city’s planning director prior to final approval of a proposed project. (Ord. 1112 § 13 (part), 2005)
17.52B.150 Monitoring program and contingency plan.
A. A monitoring program shall be included as a part of the approved mitigation plan. To insure that the performance standards of the approved mitigation plan have been met, the mitigation and/or buffer enhancement site(s) shall be monitored for a minimum of five years. The monitoring period required by the city may be extended an additional two years if the wetland or buffer is not performing as expected by the mitigation or enhancement plan. The monitoring reports shall be submitted on August 1st of each year during the monitoring period. Monitoring reports shall follow the recommendations contained in the Department of Ecology’s publication “Guidance on Wetland Mitigation in Washington State,” Part Two.
B. An acceptable surety device is required to ensure the applicant’s compliance with the terms of the mitigation agreement.
1. Performance Surety. All wetland mitigation and buffer enhancement shall be completed prior to final plat approval and/or building occupancy depending on the type of application. However, when improvements cannot be completed prior to final acceptance due to weather conditions which may negatively affect the success of the project, a performance surety may be used. The surety shall equal one hundred fifty percent of the cost of the mitigation project, and the required improvements shall be installed in a satisfactory manner within six months or less.
2. Maintenance Surety. A maintenance surety shall be required on all mitigation projects to ensure that the improvement successfully survives the monitoring periods set above.
a. Wetland Mitigation Projects. The amount of the maintenance surety shall be equal to fifteen percent of the cost of the mitigation project and the term of the surety shall reflect that of the monitoring program.
b. Buffer Enhancement Projects. The amount of the maintenance surety shall be equal to fifteen percent of the costs of the enhancement project and the term of the surety shall reflect that of the monitoring program.
3. Monitoring Deposit. A cash deposit shall be submitted with all sureties prior to final acceptance of the project to cover the estimated city’s costs to review the yearly monitoring reports and conduct a site inspection to ensure the performance standards are being met.
C. Long-Term Maintenance. To ensure the long term success of the wetland, the applicant or their heirs or successors shall be responsible for the long term maintenance of the wetland and its associated buffer. The wetland and buffer shall be kept clear of weeds, invasive plant material, lawn clippings, junk, debris, intrusions or the like. (Ord. 1112 § 13 (part), 2005)
17.52B.160 Procedural provisions.
A. Interpretation and Conflicts. Any questions regarding interpretation of this Chapter shall be resolved pursuant to the procedures set forth in Section 17.72.020 of this title.
B. Penalties and Enforcement. Compliance with this chapter and penalties for its violation shall be enforced pursuant to the procedures set forth in Title 18, Land Use Enforcement.
C. Appeals from Permit Decisions. Appeals from permit decisions shall be governed by the procedures set forth in Section 17.13.090, Appeals. (Ord. 1112 § 13 (part), 2005)