City of Mill Creek, WA Article VI Mitigation

§ 18.06.610 General mitigation requirements.

A. When an alteration to a critical area is proposed, the applicant shall first demonstrate that all reasonable efforts have been taken to avoid or minimize impacts in accordance with MCMC § 18.06.625.

B. Unless otherwise provided in this chapter, compensatory mitigation shall be provided for all unavoidable alterations of a critical area or buffer in accordance with an approved critical area report and mitigation plan, and consistent with best available science, to ensure no net loss of critical area functions and values. Mitigation shall not be implemented until final city approval of the critical area report and a mitigation plan prepared in accordance with MCMC § 18.06.530 and 18.06.620 is granted.

C. Mitigation shall be in-kind and on-site whenever possible. The director may approve exceptions to this requirement for proposals prepared in accordance with the innovative mitigation standards in MCMC § 18.06.640.

D. All areas at which mitigation is performed shall be permanently protected and managed to avoid degradation and ensure protection of critical area functions and values into perpetuity. Permanent protection shall be achieved through deed restriction or other protective covenant in accordance with MCMC § 18.06.820. Management shall be specified in a manner acceptable to the director.

(Ord. 2004-603 § 2; Ord. 2026-945 § 2 (Att. A))

§ 18.06.620 General mitigation plan requirements.

A. When compensatory mitigation is required, the applicant shall develop a mitigation plan that provides for construction, maintenance, monitoring, and contingencies of the compensation as required by conditions of approval and consistent with the requirements of this chapter.

B. The mitigation plan shall identify and demonstrate sufficient restoration, creation, enhancement, and or preservation measures to maintain the functions and values of the critical area and its buffer, and/or to prevent risk from a hazard posed by a critical area.

C. The mitigation plan shall be prepared by a qualified professional and shall contain at a minimum the following:

1. A description and detailed drawings of the activities proposed to compensate for critical area impacts, including all clearing, grading/excavation, planting, weed management, installation of habitat structures, irrigation, and other site treatments;

2. Specific information on construction or the proposed mitigation activity, including timing, sequence, equipment needs, and best management practices;

3. Documentation that the restoration, creation, enhancement and/or preservation areas shall be of the same or greater quality and endurance as the critical area(s) being replaced;

4. A description of the functions and values that the proposed compensation area(s) shall provide;

5. The goals, objectives, and performance standards that the proposed compensation action(s) shall achieve;

6. A description of how the compensation area(s) will be evaluated to determine if the performance standards are being met;

7. A program and schedule for construction and post-construction monitoring and management of the compensation project;

8. Identification of potential courses of action, and any corrective measures to be taken if monitoring or evaluation indicates project performance standards are not being met;

9. Financial guarantees to ensure that the mitigation plan is fully implemented. Financial guarantees shall be in accordance with MCMC § 18.06.650;

10. An assessment of the project’s consistency with applicable local, state and federal regulations, including the need for permits from state and/or federal agencies; and

11. Any additional information for the critical area as required by the director or subsequent sections of this chapter.

(Ord. 2004-603 § 2)

§ 18.06.625 Mitigation sequencing.

A. Applicants shall demonstrate that all reasonable efforts have been examined with the intent to avoid and minimize adverse impacts to critical areas. When an alteration to a critical area or its buffer is proposed, such alteration must be avoided, minimized, or compensated for in the following sequential order of preference:

1. Avoiding the impact altogether by not taking a certain action or parts of an action;

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 avoid or reduce impacts;

3. Rectifying the impact by repairing, rehabilitating, or restoring the affected environment;

4. Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action;

5. Compensating for the impact by replacing, enhancing, or providing substitute resources or environments; and/or

6. Monitoring the impact and taking appropriate corrective measures.

B. When demonstrating that avoidance has been adequately assessed, applicants shall address the following considerations, where applicable:

1. Alternative building locations on the property;

2. Adjustments to the project footprint or orientation;

3. Modification of non-critical area setbacks, where feasible, as a first option before encroaching into critical areas or their buffers; and

4. Multi-story or alternative building designs.

C. Mitigation for individual actions may include a combination of the measures listed in subsection A of this section.

(Ord. 2026-945 § 2 (Att. A))

§ 18.06.630 Mitigation monitoring.

A. All compensatory mitigation projects shall be monitored for the period necessary to establish that performance standards have been met, but in no event for a period less than five years following the acceptance of the installation/construction by the director.

B. Monitoring reports on the current status of the mitigation project shall be submitted to the department. The reports shall be prepared by a qualified consultant and shall include monitoring information on wildlife, vegetation, water quality, water flow, stormwater storage and conveyance, and existing or potential degradation. Reports shall be submitted in accordance with the following schedule:

1. At the time of acceptance of the installation or construction;

2. End of the growing season of the first year; and

3. Annually thereafter, for at least five growing seasons.

C. The director shall have the authority to extend the monitoring and surety period and require additional monitoring reports and maintenance activities beyond the initial five-year monitoring period for any project that involves creation or restoration of forested wetland or buffer communities, does not meet the performance standards identified in the mitigation plan, does not provide adequate replacement for the functions and values of the impacted critical area, or otherwise warrants additional monitoring.

(Ord. 2004-603 § 2; Ord. 2026-945 § 2 (Att. A))

§ 18.06.640 Innovative mitigation.

A. The city may facilitate and approve the use of mitigation banks and other forms of innovative mitigation as compensation for impacts, including off-site and/or out-of-kind mitigation projects that allow linkages between natural systems and have the potential to restore ecological processes or provide unique and beneficial ecological functions.

B. The director may approve permittee-responsible innovative mitigation projects, including mitigation projects occurring outside city boundaries, when all of the following can be clearly demonstrated by the applicant:

1. The mitigation occurs in the same watercourse basin as the impacts and if possible in the same subbasin as the impacts;

2. The proposed mitigation site will provide greater improvement of critical area functions and values compared to other sites within city boundaries;

3. The proposed mitigation is approved by the local jurisdiction wherein the site is located, by state resource agencies, and other agencies and tribes that have jurisdiction over the proposed activity; and

4. The proposed mitigation is consistent with the general purposes of this chapter and the public health, safety, and welfare.

C. Permittee-responsible innovative mitigation projects allowed under the provisions of this section include projects wherein one or more applicants, or an organization with demonstrated capability, may undertake a mitigation project together if it is demonstrated by the applicant that all of the following circumstances exist:

1. The applicant and other proponents demonstrate the organizational and fiscal capability to act cooperatively;

2. The applicant and other proponents demonstrate that long-term management of the mitigation area will be provided;

3. There is a clear potential for success of the proposed mitigation project at the identified mitigation site; and

4. Performing mitigation as part of a cooperative process results in greater protection and conservation of critical areas than would be achieved using traditional mitigation approaches.

D. In lieu of designing, constructing and monitoring their own mitigation project, an applicant may request approval to purchase mitigation credits from a certified mitigation bank to compensate for unavoidable impacts to wetlands. The director may approve the use of a mitigation bank in accordance with MCMC § 18.06.960(D)(1).

(Ord. 2004-603 § 2; Ord. 2015-796 § 2; Ord. 2026-945 § 2 (Att. A))

§ 18.06.650 Surety to ensure implementation, maintenance, and monitoring.

A. If the development proposal is subject to compensatory mitigation, the applicant shall enter into an agreement with the city to complete the mitigation plan approved by the city and shall post a mitigation surety to ensure mitigation is fully functional.

B. The surety shall be in the amount of 125 percent of the estimated cost of the uncompleted actions or the estimated cost of restoring the functions and values of the critical area that are at risk, whichever is greater. The surety shall be based on a detailed itemized cost estimate of the mitigation activity including clearing and grading, plant materials, plant installation, irrigation, weed management, and all other costs.

C. The surety shall be in the form of an assignment of funds, bond, security device, or other means acceptable to the city attorney.

D. The performance surety authorized by this section shall remain in effect until the city determines, in writing, that the standards bonded for have been met. Once the mitigation installation has been accepted by the director, the bond may be reduced to 25 percent of the original mitigation cost estimate and shall become a maintenance surety. Said maintenance surety shall generally be held by the city for a period of five years to ensure that the required mitigation has been fully implemented and demonstrated to function, and may be held for longer periods under MCMC § 18.06.630(C).

E. Depletion, failure, or collection of surety funds shall not discharge the obligation of an applicant to complete required mitigation, maintenance, monitoring, or restoration.

F. Public development proposals shall be relieved from having to comply with the bonding requirements of this section if public funds have previously been committed for mitigation, maintenance, monitoring, or restoration.

G. Any failure to satisfy critical area requirements established by law or condition including, but not limited to, the failure to provide a monitoring report within 30 days after it is due or comply with other provisions of an approved mitigation plan shall constitute a default. Upon notice of any default, the city may demand immediate payment of any financial guarantees or require other action authorized by the city code or any other law.

H. Any funds paid or recovered pursuant to this section shall be used to complete the required mitigation or other authorized action.

I. The director may authorize a one-time temporary delay, up to 120 days, in completing mitigation activities 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. The request for the temporary delay shall include a written justification documenting the environmental constraints that preclude implementation of the mitigation plan and shall include a financial guarantee. The justification shall be verified by the city before approval of any delay.

J. The provisions of Chapters 16.20 and 17.44 MCMC shall also apply if necessary to ensure adequate protection of the public interest.

(Ord. 2004-603 § 2)