14.04.540 Performance standards – Compensatory mitigation requirements.
A. Requirements for Compensatory Mitigation.
1. Compensatory mitigation for alterations to wetlands shall be used only for unavoidable impacts that remain after application of mitigation sequencing and shall achieve equivalent or greater biologic functions.
2. Compensatory mitigation plans shall be consistent with the following documents, as applicable:
a. Wetland Mitigation in Washington State – Part 1: Agency Policies and Guidance (Version 2), Ecology Publication No. 20-06-010, as revised;
b. Wetland Mitigation in Washington State – Part 2: Developing Mitigation Plans – Version 1, Ecology Publication No. 06-06-011b, as revised; and
c. Selecting Wetland Mitigation Sites Using a Watershed Approach (Western Washington), Ecology Publication No. 09-06-32b as revised.
3. Compensation ratios shall be consistent with subsection H of this section or as otherwise approved by the Washington Department of Ecology and/or the U.S. Army Corps of Engineers.
4. Compensatory mitigation requirements may also be determined using the credit/debit tool described in Calculating Credits and Debits for Compensatory Mitigation in Wetlands of Western Washington: Final Report (Ecology Publication No. 10-06-011, or as revised) consistent with subsection (H)(5) of this section.
B. Mitigation shall be required in the following order of preference:
1. Avoiding the adverse impact altogether by not taking a certain action or parts of an action.
2. Minimizing adverse impacts by limiting the degree or magnitude of the action and its implementation, by using appropriate technology, or by taking affirmative steps to avoid or reduce impacts.
3. Rectifying the adverse impact by repairing, rehabilitating, or restoring the affected environment.
4. Reducing or eliminating the adverse impact over time by preservation and maintenance operations.
5. Compensating for the adverse impact by replacing, enhancing, or providing substitute resources or environments.
6. Monitoring the impact and taking appropriate corrective measures when necessary.
Application of the above mitigation order of preference shall be consistent with guidance from the State Department of Ecology, Wetland Mitigation in Washington State – Part 1: Agency Policies and Guidance (Version 2) Ecology Publication No. 20-06-010 by providing for a higher avoidance threshold for wetlands such as Category I or II wetlands, which perform a high level of functions, than the avoidance threshold for wetlands such as Category IV wetlands, which provide a low level of functions.
C. Preference of Mitigation Methods. Compensatory mitigation methods shall address functions affected by the alteration to achieve functional equivalency or improvement. Compensatory mitigation methods shall occur in the following order of preference:
1. Restoration.
a. Reestablishment. Restoring wetlands on upland sites that were formerly wetlands. “Wetland restoration” refers to actions performed to reestablish wetland functional characteristics and processes that have been lost by alterations, activities, or catastrophic events within an area that no longer meets the definition of a wetland.
b. Rehabilitation. Improving or repairing the performance of processes, and therefore functions, in an existing wetland. Rehabilitation actions usually occur in wetlands that are highly degraded because one or more environmental processes have been disrupted. Rehabilitation actions should focus on restoring hydrologic processes that have been disturbed or altered by human activity (e.g., breaching a levee in a floodplain).
2. Creation. Creating wetlands on disturbed upland sites such as those with vegetative cover consisting primarily of nonnative introduced species. “Wetlands creation” refers to actions performed to manipulate existing physical, chemical, or biological characteristics to intentionally establish a wetland at a site where it did not formerly exist. Creation should only be attempted when there is a consistent source of hydrology and it can be shown that the surface and subsurface hydrologic regime is conducive for the wetland community that is being designed.
3. Preservation. Protecting/maintaining wetlands by removing a threat to, or preventing the decline of, wetland conditions by an action in or near a wetland, such as purchasing land or easements.
4. Enhancement. Manipulating physical, chemical, or biological characteristics of a degraded aquatic resource to heighten, intensify, or improve a specific aquatic resource function(s). Such enhancement should be part of a mitigation package that includes replacing the impacted area meeting appropriate ratio requirements.
D. Type of Mitigation. Compensatory mitigation shall address the functions affected by the proposed project, with an intention to achieve functional equivalency or improvement of functions (“in kind”). The goal shall be for the compensatory mitigation to provide similar wetland functions to those lost, except the city may allow out-of-kind replacement of wetland type or functions when either:
1. The lost wetland provides minimal functions or functions that are relatively abundant in the area, and the proposed compensatory mitigation action(s) will provide equal or greater functions or will provide functions shown to be limiting within a watershed through a watershed restoration plan, as defined in RCW 89.08.460, or through equivalent information provided by a qualified professional in a critical areas report; or
2. Out-of-kind replacement of wetland type or functions will best meet watershed goals or restoration priorities in the final Lake Washington/Cedar/Sammamish Watershed (WRIA 8) Chinook Salmon Conservation Plan (WRIA 8 Salmon Plan) initially adopted by the city council in 2005, and as updated or supplemented thereafter.
E. Approaches to Compensatory Mitigation. Mitigation for lost or diminished wetland and buffer functions shall rely on one or more of the approaches listed below.
1. Wetland Mitigation Banks. Use of credits from a certified wetland mitigation bank may be approved to compensate for impacts consistent with the terms of the certified mitigation bank instrument. Use of credits from a wetland mitigation bank certified under Chapter 173-700 WAC is allowed if:
a. The director determines that it would provide appropriate compensation for the proposed impacts;
b. The impact site is located in the service area of the bank or, if approved by Ecology, the bank’s Interagency Bank Review Team, and the director, outside of the service area; and
c. Compensation ratios for projects using bank credits is consistent with ratios specified in the certified mitigation bank instrument.
2. In-Lieu Fee Mitigation. Use of credits from an approved in-lieu-fee (ILF) program may be approved to compensate for impacts located within the service area specified in the ILF program instrument when all of the following apply:
a. The director determines that it would provide environmentally appropriate compensation for the proposed impacts.
b. The proposed use of credits is consistent with the terms and conditions of the approved ILF program instrument.
c. Projects using ILF credits shall have debits associated with the proposed impacts calculated by the applicant’s qualified wetland professional using the credit assessment method specified in the approved instrument for the ILF program.
3. Permittee-Responsible Mitigation. Permittee-responsible mitigation may be approved to compensate for impacts when all of the following apply:
a. The director determines that it would provide environmentally appropriate compensation for the proposed impacts.
b. The compensation site is:
(1) Located and designed using a watershed approach consistent with Selecting Wetland Mitigation Sites Using a Watershed Approach (Western Washington) (Ecology Publication No. 09-06-32, or as revised) (more preferred);
(2) On site and in kind (less preferred); or
(3) Off site and/or out of kind (least preferred).
F. Selection of Mitigation Approach. The appropriate compensatory mitigation approach shall be selected based on a demonstration in a critical areas report prepared by the applicant’s qualified wetland professional that the proposed approach will best offset the impacts and provide the greatest ecological benefits. In addition to the requirements listed in BMC 14.04.520, a critical areas report shall include a discussion of each of the mitigation approaches listed in subsection E of this section and a clear rationale for the mitigation approach and site chosen, including, but not limited to, the following:
1. Comparison of the impacted wetland’s and each available mitigation approach’s functions that are or could be provided.
2. Comparison of the width and characteristics of each available mitigation approach’s existing or proposed buffer.
3. Comparison of each available mitigation approach’s existing or potential connectivity to protected fish or wildlife habitat corridors or larger patches of habitat.
4. Comparison of potential threats to long-term sustainability of each of the available mitigation approaches based on adjacent existing and planned land uses.
5. Comparison of each of the available mitigation approaches’ contribution to achievement of goals or restoration priorities in local and regional plans, including but not limited to the Imagine Bothell… Comprehensive Plan (2015, or as revised), the Bothell 2021 Storm and Surface Water Master Plan Update (or as revised), the Shoreline Restoration Plan (2013 or as revised), and the Lake Washington/Cedar/Sammamish Watershed (WRIA 8) Chinook Salmon Conservation Plan (2005) as updated or supplemented thereafter.
G. Mitigation Timing. Compensatory mitigation projects shall be completed with an approved monitoring plan prior to activities that will disturb wetlands. In all other cases, mitigation shall be completed immediately following disturbance and prior to use or occupancy of the activity or development. Construction of compensatory mitigation projects shall be timed to reduce adverse impacts to existing fisheries, wildlife, and flora.
The director may authorize a one-time temporary delay, up to 120 calendar days, in completing minor construction and landscaping when environmental conditions could produce a high probability of failure or significant construction difficulties. The delay shall not create or perpetuate hazardous conditions or environmental damage or degradation, and the delay shall not be injurious to the health, safety, and general welfare of the public. The request for the temporary delay must include a written justification that documents the environmental constraints that preclude implementation of the mitigation plan. The justification must be verified and approved by the city and include a financial guarantee.
H. Compensation Ratios.
1. Standard Compensation Ratios.
a. The ratios in Table 14.04.540-1 shall apply to permittee-responsible compensation that is in kind, is the same or higher category as the impacted wetland, is the same hydrogeomorphic class as the impacted wetland, is timed concurrent with alteration, and has a high probability of success.
b. These ratios do not apply to remedial actions resulting from unauthorized alterations; greater ratios shall apply in those cases.
c. These ratios do not apply to the use of credits from a state certified wetland mitigation bank, use of an ILF program, or advance mitigation implemented by the permittee. When credits from a certified bank or ILF program are used, compensation ratios should be consistent with the requirements of the bank’s or program’s certification. Ratios applicable to advance mitigation shall be determined on a case-by-case basis in consultation with state and/or federal agencies.
d. The first number in each cell of Table 14.04.540-1 specifies the acreage of compensatory mitigation and the second specifies the acreage of wetlands altered.
e. When combining mitigation methods, compensation ratios may be adjusted consistent with Section 6B.4.2 in Wetland Mitigation in Washington State – Part 1: Agency Policies and Guidance (Version 2), Ecology Publication No. 20-06-010, as revised.
Type of Wetland | Creation or Reestablishment | Rehabilitation | Enhancement2 | |
|---|---|---|---|---|
Category I | 4:1 | 8:1 | 16:1 | 16:1 |
Category II | 3:1 | 6:1 | 12:1 | 12:1 |
Category III | 2:1 | 4:1 | 8:1 | 8:1 |
Category IV | 1.5:1 | 3:1 | 6:1 | 6:1 |
1All proposed preservation sites shall meet the preservation criteria listed in subsection (H)(3) of this section. To the maximum extent practicable, preservation should be done in conjunction with wetland creation and reestablishment.
2Applicants proposing preservation only or enhancement only should provide a complete credit-debit analysis using Calculating Credits and Debits for Compensatory Mitigation in Wetlands of Western Washington: Final Report (Ecology Publication No. 10-06-011, or as revised). The ratios in Table 14.04.540-1 only apply when the credit-debit tool is not applicable.
2. Increased Compensation Ratios. The director may increase the ratios under the following circumstances:
a. Uncertainty exists as to the probable success of the proposed restoration or creation;
b. A significant period of time will elapse between adverse impact and replication of wetland functions;
c. Proposed compensatory mitigation will result in a lower category wetland or reduced functions relative to the wetland being adversely impacted; or
d. The impact was an unauthorized impact.
3. Preservation Criteria.
a. The preservation site is determined to be under demonstrable threat of destruction, adverse modification, or substantive degradation; that is, the site is likely to suffer serious negative impacts from on-site or off-site activities (e.g., logging of forested wetlands).
b. The area proposed for preservation is of high quality or critical for the health and ecological sustainability of the watershed or sub-basin. Some of the following features may indicate high-quality sites:
(1) Category I or II wetland rating, including Wetlands of High Conservation Value as identified by Washington Department of Natural Resource’s Natural Heritage Program.
(2) Rare or irreplaceable wetland type (e.g., peatlands, mature forested wetlands) or aquatic habitat that is a rare or limited resource in the area.
(3) Habitat for threatened or endangered species (state and federal).
(4) Provides biological and/or hydrologic connectivity.
(5) Of regional or watershed importance (e.g., listed as priority site in a watershed, salmon recovery, or basin plan).
(6) Large size with high species diversity (plants, animals, or both), high abundance of native species, or both.
(7) A site that is continuous with the head of a watershed, or with a lake or pond in an upper watershed that significantly contributes to hydrologic processes and water quality.
c. The site is permanently protected with a legal mechanism such as a conservation easement.
d. The site has adequate buffers to ensure that the preserved wetland will not be degraded over time. The buffer width and vegetative condition must be sufficient to protect the wetland and its functions from encroachment and degradation. Existing and potential future land uses (based on current zoning designations) dictate the width necessary for a buffer that is adequate to protect the wetland and its functions; see buffer widths in Chapter 6C in Wetland Mitigation in Washington State – Part 1: Agency Policies and Guidance (Version 2), Ecology Publication No. 20-06-010, as revised.
4. Other Types of Impacts. The director may require mitigation for impacts to wetlands other than fill, such as a conversion from one wetland type to another, shading, long-term temporary alterations, and indirect effects, consistent with Wetland Mitigation in Washington State, Parts 1 and 2 (respectively, Ecology Publications No. 20-06-010, February 2021, and No. 06-06-011, March 2006, or as revised). The area of impact requiring compensation and the compensation ratios will be determined on a case-by-case basis considering the analysis provided in a critical areas report prepared by a qualified professional.
5. Credit/Debit Method. To more fully protect functions and values, and as an alternative to the compensation ratios found in Wetland Mitigation in Washington State, Part 1 (Ecology Publication No. 20-06-010, February 2021, or as revised), the director may allow compensatory mitigation based on the “credit/debit” method developed by the Department of Ecology in Calculating Credits and Debits for Compensatory Mitigation in Wetlands of Western Washington: Final Report (Ecology Publication No. 10-06-011, Olympia, WA, March 2012, or as revised). (Ord. 2349 §§ 1, 2, 2021; Ord. 2010 § 1 (Exh. B), 2009; Ord. 1946 § 3, 2005).