1. Riparian management zones (RMZs).

2. Biodiversity areas.

4. Riverine habitat.

5. Wildlife habitat corridor.

1. Low impact uses and development activities consistent with the purpose and function of the FWHCA and that do not detract from its integrity may be permitted within the conservation area depending on the sensitivity of the habitat area, based on a study from a qualified professional. Examples of uses and development activities that may be permitted include pervious trails, viewing platforms, stormwater management facilities such as grass-lined swales, utility easements, and other similar; provided, that any impacts to the habitat resulting from such permitted facilities shall be fully mitigated.

2. Streambank stabilization is allowed to protect existing structures from channel migration, in accordance with an approved critical areas report. All actions associated with such activity shall comply with appropriate State and Federal guidelines and shall require any necessary permits from government agencies prior to the start of work.

3. Streambank stabilization is not permitted to protect new structures from channel migration, except where such stabilization is achieved through bioengineering methods in accordance with an approved critical areas report. All actions associated with such activity shall comply with appropriate State and Federal guidelines and shall require any necessary permits from government agencies prior to the start of work.

4. Any of the activities allowed pursuant to SMC 14.255.060.

1. Establishment of buffer zones;

2. Preservation of vegetation that contributes to the functions and values of the FWHCA;

3. Limitation of public access to the habitat area, including fencing to deter unauthorized access;

4. Seasonal restriction of development activities;

5. Establishment of a duration and timetable for periodic review of mitigation activities; and requirement of a performance bond, when necessary, to ensure completion and success of proposed mitigation. (Ord. 2533, 2025)

1. Type S: all waters within the ordinary high-water mark inventoried as “shorelines of the State” under Chapter 90.58 RCW and the rules promulgated pursuant thereto, but not including those waters associated with wetlands as defined in Chapter 90.58 RCW. These streams are identified as “Shorelines of the State” under the City of Snohomish Shoreline Master Program.

2. Type F: segments of natural waters that are not Type S waters, that are either perennial or intermittent and have salmonid fish use or the potential for fish use.

3. Type N: segments of natural waters that are not Type S or Type F. They are either perennial or intermittent, do not have fish or the potential for fish, and are nonheadwater streams.

4. Type O: streams with no natural surface water connection to Type S, F, or N waters.

1. The following riparian management zones are established for streams:

2. The RMZ buffer is measured horizontally from the ordinary high water mark (OHWM) of the stream, river, or lake or from the channel migration zone (CMZ), where present, to the specified width.

3. The RMZ buffer shall not extend landward of the Riverfront Trail, due to the cultural importance of the Snohomish Historic District.

1. A water-dependent, water-related, or water-enjoyment activity for which there are no feasible alternatives that would have less adverse impact on the RMZ.

2. Infrastructure or utilities that cannot be feasibly located outside of the RMZ consistent with the mitigation sequencing requirements of SMC 14.255.110(E), that minimize the impact, that mitigate any unavoidable impact to functions, and receive authorization from applicable Federal and State regulating agencies, as necessary.

3. Mitigation for activities permitted by this chapter, provided the activity results in no net loss of riparian habitat functions on the site, including but not limited to:

4. Trails and wildlife viewing structures, provided such trails and structures minimize the impact and are constructed to avoid interfering with hydrology of the water body and do not result in increased sediment or pollution entering the water body.

1. RMZ buffer width reduction and enhancement is targeted for buffer areas that have minimal functions and values due to existing physical characteristics.

2. The applicant demonstrates that proposed buffer enhancement, together with proposed buffer width reduction, will result in an increase in the functional value of the buffer when compared with the functional value of the standard RMZ buffer.

3. The applicant includes a comparative analysis of RMZ buffer values prior to and after enhancement, and demonstrates compliance with this section, as part of the critical area report described in SMC 14.280.070.

4. The RMZ buffer width is not reduced below 75 percent of the standard width.

5. The functions and values of the stream protected by the RMZ buffer are not decreased.

1. For stream meandering proposals, the modification improves instream habitat and flow conveyance.

2. The buffer width reduction is the minimum necessary to accommodate existing and proposed improvements and/or site conditions.

3. The density of buffer vegetation is increased to the extent feasible within the reduced buffer area to mitigate the impact to the critical area.

1. Existing uses and developments with improvements located in an RMZ may be repaired and maintained.

2. Existing uses and developments may be expanded, enlarged, or otherwise modified pursuant to the following:

3. Modifications to existing developments located within the RMZ shall not result in a net loss of ecological functions and values to the water body and/or habitat area.

1. Evaluate the RMZ to identify the best sites to restore and consider connectivity and adjacency to other priority habitats.

2. Improve aquatic connectivity by replacing culverts and removing barriers to movement.

3. Revegetate with native plants and consider improvements for wildlife by integrating structures necessary for nesting, breeding, and foraging.

4. As existing development is remodeled or replaced, incorporate wider setbacks for streams.

5. Control access to the RMZ during construction to limit soil compaction. Avoid operating equipment near water bodies to reduce sedimentation and soil compaction.

6. Chemicals not approved by the Washington State Department of Ecology for use within the RMZ shall not be used.

1. When existing impervious surfaces or other built structures functionally or physically isolate the buffer from the water body, the regulated RMZ shall extend landward from the OHWM or CMZ, whichever is greater, and terminate at the waterward edge of the impervious surface or manmade structure. Development activities that occur within the area of functional isolation, or further landward, are exempt from the requirement to provide a critical areas report.

2. The Planning Director may rely on a site visit, aerial photographs, other evidence provided by the applicant or the applicant’s qualified professional, and consultation with the WDFW in making a determination to reduce the width of the RMZ based on functional and/or physical isolation. (Ord. 2533, 2025)

1. The corridor shall form one contiguous tract that connects high value habitat areas to each other.

2. The corridor should include and/or connect other critical areas, wooded areas, and open space tracts on site or on adjacent properties, where present.

3. The corridor should measure a minimum of 100 feet in width. A lesser width may be approved if it can be shown that a lesser corridor width supports and maintains the corridor’s function and value, as demonstrated through an approved habitat management plan.

4. Habitat corridors do not parallel streams and riparian areas, except as necessary to connect two features as described in this subsection.

1. A scaled site plan pursuant to SMC 14.255.070(B)(4) that also includes:

2. A narrative description of the nature and intensity of the proposed activity or development.

3. A narrative of any Federal or State management recommendations, including WDFW habitat management recommendations, that have been developed for species or habitats located on or adjacent to the project area.

4. An analysis of the potential direct and indirect impacts of the proposed activity or development on the wildlife species and habitat identified for protection, including potential impacts to water quality and soil.

5. A mitigation plan ensuring no net loss of ecological functions, meeting the requirements of SMC 14.255.090 and the following:

1. Narrative description of how the proposed activity is for a water-dependent, water-related, or water-enjoyment use.

2. Assessment of how the proposed activity cannot be feasibly located outside of the RMZ on the site, including alternative building locations on the property, adjustments to the project footprint and orientation, modification to setbacks, and increase in building height before encroaching into critical areas or their buffers.

3. Analysis of how the proposal will not adversely affect the connectivity of habitat functions.

1. Water quality monitoring shall be conducted during construction activities for detection of pollution impacts.

2. The monitoring program protocol shall include observations and measurements of riparian integrity and quality, including buffer width, riparian corridor continuity or fragmentation, species integrity, stand age, and plant survival rates.

1. When appropriate due to the type of habitat or species present or the proposed project area, the Planning Director may require the habitat management plan to include an evaluation by and any recommendations from WDFW, local tribal entity, or other qualified professional regarding the analysis contained within the habitat management plan and any proposed mitigation measures or programs.

2. Information from WDFW’s Habitat at Home program may be required, as appropriate. (Ord. 2533, 2025)

1. The site plan shall show all improvements and utilities in relationship to the daylighting, topography, daylighted stream course, hydrologic flow before and after daylighting, and where the daylighted stream will connect once the culvert is removed.

2. Demonstrate that the daylighting plan will achieve natural meander patterns, gentle and stable side slopes, and erosion control features that include native vegetation on the stream banks, and restoration of water flow characteristics compatible with fish habitat areas.

3. A stream channel planting plan using appropriate native stream vegetation. Native vegetation normally associated with streams shall be required, emphasizing plants that provide benefits to fish and wildlife.

4. A vegetative buffer plan, except as permitted to be reduced pursuant to SMC 14.280.040(E).

5. Prior to placing the stream into a new channel, a qualified professional approved by the City shall inspect the completed channel and issue a written report to the City stating that the new stream channel complies with the requirements of this section prior to daylighting the stream. The cost of the inspection and the report shall be borne by the applicant. The applicant shall also pay the cost of peer review by the City if the Planning Director determines the review is necessary.

6. A survey of the daylighted stream.