A. 
Certain activities shall be exempt from the provisions of this chapter; provided, that they are conducted using locally adopted best management practices and that they result in no net loss of the critical area functions and values. Best management practices shall be used for tree and vegetation protection, construction management, erosion and sedimentation control, water quality protection, and regulation of chemical applications. The city shall observe the use of best management practices to ensure that the activity does not result in degradation of the critical area or buffer. Exempt activities include the following:
1. 
Existing and ongoing agricultural activities as defined in this chapter; if established prior to 1992 and after that date do not cause permanent conversion of a critical area through actions such as ditching, draining, clearing, grading, and/or filling; provided, that:
a. 
The activity is conducted as part of normal agricultural activities. The exemption does not apply to the full or partial conversion of agricultural land to nonagricultural uses;
b. 
The activity does not destroy, kill, harass, or otherwise harm species listed as threatened or endangered under the Federal Endangered Species Act of 1973, or the habitats on which those species depend;
c. 
The property or portion of the property considered for exemption has been actively farmed since 1992, and not been idle for two consecutive years;
d. 
The agricultural activities comply with the flood hazard provisions of Chapter 15.20 MCMC and other applicable city regulations; and
e. 
The exemption is limited to specific areas upon which lawfully established agricultural activities are being conducted. A determination that a portion of a site is exempt shall not extend to other portions of the site that do not meet the requirements of this section.
2. 
Activities conducted pursuant to previous critical area review, including activities subject to previous development permits and approvals and construction approvals, provided all of the following conditions have been met:
a. 
The provisions of this chapter have been previously addressed as part of another approval;
b. 
There have been no material changes in the potential impact to the critical area or buffer since the prior review;
c. 
There is no new critical area information available for the site or adjacent areas and there have been no substantial changes to site conditions since the original study was prepared;
d. 
The permit or approval has not expired or, if no expiration date, no more than five years has elapsed since the issuance of that permit or approval or adoption of this chapter, whichever is later; and
e. 
Compliance with all standards or conditions placed upon the prior permit or approval has been achieved or secured.
3. 
The creation of new pedestrian trails on public land or on private land with public access provided by a public access easement or another method approved by the director, which comply with the following requirements:
a. 
Adverse impacts must be mitigated in accordance with MCMC § 18.06.625;
b. 
The trail must be placed within the outer 25 percent of the critical area buffer to the greatest extent possible; and
c. 
Fencing or other control mechanisms shall be installed at the edge of the trail closest to the critical area.
4. 
Select vegetation removal activities including the following; provided, that no vegetation shall be removed from a wetland, fish and wildlife habitat conservation area, or erosion/land-slide hazard area or their associated buffers without prior written approval; and provided, that disturbed areas are revegetated with native, noninvasive species approved by the city:
a. 
The removal of invasive weeds, such as Himalayan blackberry, using hand labor, city-approved light equipment, and/or authorized herbicides; provided, that all cut vegetation shall be left within the critical area or buffer unless removal is warranted due to the potential for disease transmittal to other healthy vegetation; and
b. 
If a tree to be removed provides critical habitat, such as an eagle perch, a qualified wildlife biologist shall be consulted to determine timing and methods of removal that will minimize impacts.
5. 
The removal of hazard trees from critical areas and buffers; provided, that written approval from the city is required before the removal of hazard trees, and:
a. 
The applicant submits a report from a certified arborist, or registered landscape architect, that documents the hazard and provides a replanting schedule for the replacement trees. The director can waive this requirement if the hazard potential is readily apparent to city staff;
b. 
Tree cutting shall be limited to limbing and crown thinning, unless otherwise recommended and justified by a qualified professional. Prior to any tree modification, the applicant shall demonstrate that retention or creation of a snag was considered as an alternative to complete tree removal;
c. 
The landowner shall replace any trees that are felled or limbed with new trees at a ratio of two replacement trees for each tree felled or limbed within one year in accordance with an approved restoration plan. The director may reduce the ratio when it can be demonstrated that a lower ratio is adequate to protect critical areas. Tree species that are native and indigenous to the site shall be used; and
d. 
Hazard trees determined to pose an imminent threat or danger to public health or safety, property, or cause serious environmental degradation may be removed by the landowner prior to receiving written approval from city; provided, that a reasonable attempt is made to contact the city prior to removal and within 14 days following such action, the landowner shall submit a restoration plan that demonstrates compliance with the provisions of this chapter.
6. 
The application of herbicides, pesticides, organic or mineral-derived fertilizers, or other hazardous substances, if necessary, as approved by the director; provided, that their use shall be restricted in accordance with Department of Fish and Wildlife Management Recommendations, and the regulations of the Department of Agriculture and/or the U.S. Environmental Protection Agency.
7. 
Minor operation, maintenance, and/or repair of existing structures, infrastructure improvements, utilities, public or private roads, dikes, levees or drainage systems, if the activity does not require construction permits, does not further alter, impact, or encroach upon the critical area or buffer, and there is no increased risk to life or property as a result of the proposed operation, maintenance, or repair.
8. 
Normal maintenance of groundcover or other vegetation lawfully planted in a critical area or buffer area that was disturbed prior to the effective date of the ordinance codified in this chapter; provided, that no further disturbance is created.
9. 
Minor site investigative work, such as surveys, soil logs, percolation tests and other related activities, when required by the city, or a state or federal agency, where such activity does not require construction of roads, significant excavation or grading, or use of heavy machinery; provided, that impacts on critical areas are minimized and disturbed areas are restored immediately to the preexisting level of function and value.
10. 
Passive outdoor activities such as recreation, education, and scientific research activities that do not alter or degrade the critical area or buffer, including fishing, hiking, and bird watching.
11. 
Activities involving artificial wetlands or surface water systems; provided, that wetlands, streams, lakes, or ponds created as mitigation for approved land use activities or that provide critical habitat shall be regulated under the provisions of this chapter.
12. 
Emergency actions that impact a critical area or its buffer provided such actions use reasonable methods to address the emergency and have the least possible impact to the critical area or its buffer. Prior to an emergency action, the director shall provide written determination on a case-by-case basis of the emergency action that satisfies the general requirements of this section. In the event a person or agency determines that the need to take emergency action is so urgent that there is insufficient time for review by the director, such emergency action may be taken immediately. Emergency actions that must be undertaken immediately or for which there is insufficient time for full compliance with this chapter include actions necessary to:
a. 
Prevent an imminent threat to public health or safety; or
b. 
Prevent imminent danger to public or private property; or
c. 
Prevent an imminent threat of serious environmental degradation.
B. 
The applicant shall obtain written confirmation from the director that the proposed activities meet the requirements for exemption as defined by the section before the activity is initiated. All exempted activities shall use reasonable methods to avoid potential impacts to critical areas. To be exempt from this chapter does not give permission to alter or degrade a critical area or ignore risk from natural hazards. Any damage to, or alteration of, a critical area must be promptly restored, rehabilitated, or replaced at the responsible party’s expense to the director’s satisfaction.
(Ord. 2004-603 § 2; Ord. 2026-945 § 2 (Att. A))
A. 
If the application of this chapter would prohibit a development proposal by a public agency to install or provide streets or utilities, the agency or utility may apply for an exception pursuant to this section.
B. 
An application for a public agency and utility exception shall be made to the city and shall include a critical area identification form; critical area report and mitigation plan, if necessary; and any other pertinent project documents/studies. The director shall prepare a determination approving, approving with conditions, or denying the request. This determination shall be based on review of the submitted information, a site inspection, and the proposal’s ability to comply with all of the following criteria:
1. 
There is no other practical alternative to the proposed development with less impact on critical areas and all reasonable measures have been taken to minimize impacts to critical areas;
2. 
The application of this chapter would unreasonably restrict the ability to provide street or utility services to the public;
3. 
The proposal does not pose a significant threat to the public health, safety, or welfare on or off the site; and
4. 
The proposal includes measures to compensate for impacts to critical area function and values consistent with the requirements of this chapter.
(Ord. 2004-603 § 2)
A. 
Applicability. An exception to the provisions of this chapter may be considered by the hearing examiner if application of this chapter would deny all reasonable use of the subject property and upon a showing by the applicant of all the following elements:
1. 
The proposed activity will result in minimal alteration of existing contours, vegetation, fish and wildlife resources, hydrological conditions, and geologic conditions and will have a minimal effect on critical area functions;
2. 
The proposed activity will not jeopardize the continued existence of endangered, threatened, sensitive, or monitored species as listed by the federal or state government;
3. 
The proposed activity will not cause material degradation of habitat, ground water or surface water quality;
4. 
The proposed activity will comply with all local, state, and general laws, including those related to environmental protection, sediment control, pollution control, floodplain restrictions, and on-site wastewater disposal;
5. 
There will be no damage to public or private property and no threat to the health or safety of people on or off the site; and
6. 
The inability to derive reasonable economic use of the property is not the result of actions by the applicant in segregating or dividing the property and/or creating or adding to the undevelopable condition.
B. 
Maximum Area. The maximum developable area, including all structures and impervious surfaces, may not exceed:
1. 
Single-unit dwelling: 2,500 square feet.
2. 
Other uses: 2,500 square feet, except that the director may authorize a higher maximum if a neighborhood land analysis demonstrates that such an increase is required to achieve subsection A of this section.
C. 
Submittal Requirements. The following must be submitted with a request for a reasonable use exception:
1. 
A critical areas report from a qualified professional detailing how the project has been designed to avoid and minimize impacts to the critical area and buffer. The report must detail the anticipated impact on the critical area and buffer, along with specific mitigation measures, which may include restoration of previously impacted critical areas;
2. 
A site plan showing the critical area, buffer, natural features, topography, and proposed development area;
3. 
A proposed monitoring plan for a minimum of five years, including submittal of at least one report per year, or as required by MCMC § 18.06.630, to the city;
4. 
A detailed review of the permitted uses allowed in the underlying zoning district with supporting information explaining why all other permitted uses that may have less impact to the critical area and buffer are not feasible; and
5. 
A neighborhood land analysis, if required by subsection (B)(2) of this section.
(Ord. 2004-603 § 2; Ord. 2010-718 § 14 (Exh. N); Ord. 2026-945 § 2 (Att. A))
A. 
Applicability. Nonconforming uses and structures are allowed within critical areas, buffers, and building setbacks, subject to the limitations in this section, if they are otherwise consistent with this chapter and other applicable regulations. The director may impose conditions on any underlying permit or approval as necessary to ensure consistency with the provisions of this chapter.
B. 
Maintenance. Existing nonconforming uses and structures may be maintained if they are not expanded within the critical area, buffer, or building setback area.
C. 
Modifications. Modifications to nonconforming uses and structures must comply with the following requirements:
1. 
Modification or Replacement. Modification or replacement of nonconforming structures is allowed if the modification, replacement, or related activity does not increase the existing footprint of the structure within the critical area, buffer, or building setback area.
2. 
One-Time Expansion. Nonconforming structures and associated impervious surfaces are allowed a one-time expansion of up to 1,000 square feet within buffers or building setback areas, subject to the following requirements:
a. 
Eligibility. Developments that required a reasonable use exception for approval are not eligible for a one-time expansion.
b. 
Geologically Hazardous Areas. If the nonconforming structure and associated impervious surfaces are within a buffer or building setback area required for a geologically hazardous area, a critical area report consistent with MCMC § 18.06.530 must be provided demonstrating that the expansion will not increase risk to life or property.
c. 
Wetlands or Fish and Wildlife Habitat Conservation Areas. If the nonconforming structure and associated impervious surfaces are within buffer or building setback area required for wetlands or fish and wildlife habitat conservation areas, the following requirements apply:
i. 
No portion of the expansion may be located closer to the critical area than the noncon-forming structure and associated impervious areas, or closer than 20 feet from the critical area or 100 feet from the nearest stream edge as determined by MCMC § 18.06.1050, whichever is greater.
ii. 
A critical area report consistent with MCMC § 18.06.530 must be provided demonstrating no net loss of buffer functions or values.
iii. 
Impacts to the critical area must be mitigated in accordance with MCMC § 18.06.610.
d. 
Notice on Title. The property owner shall file a notice on title with the Snohomish County auditor that:
i. 
Complies with MCMC § 18.06.820; and
ii. 
States that the expansion constitutes the one-time allowance under this subsection and that no further expansion within the critical area, buffer, or building setback area is permitted.
D. 
Conversions. Nonconforming impervious surfaces may be converted to a use that will not have greater impact on the critical area, such as converting a parking lot to a building with an approved stormwater system, if impact minimization measures are implemented in accordance with MCMC § 18.06.930(A)(3).
(Ord. 2004-603 § 2; Ord. 2026-945 § 2 (Att. A))