Lake Stevens planners review major update to critical areas ordinance, weigh stream buffer options

City planning staff told the Lake Stevens Planning Commission on Sept. 17 that an update to the city’s critical areas ordinance (chapter 14.88) will be needed to align with the Growth Management Act and recent best-available science, and that one proposed approach from the Washington Department of Fish and Wildlife (WDFW) could vastly increase riparian buffer widths.

The update is part of the city’s periodic implementation of its comprehensive plan following the 2024 update, Principal Planner David Levitan said. A consultant prepared a gaps analysis and a best-available-science report that staff distributed in August; attachments in the commission packet identify five critical-area types under the Growth Management Act—wetlands; critical aquifer recharge areas; frequently flooded areas; geologically hazardous areas; and fish and wildlife habitat conservation areas (streams are a primary focus).

Commissioners were briefed on a WDFW-informed model that establishes riparian management zones based on the “site potential tree height” of species in a riparian area—i.e., the projected maximum height of native trees at approximately 200 years of age—and then sets a corresponding buffer. Levitan said many stream reaches in the city were flagged with a site potential tree height of about 235 feet, which would translate to buffers several times larger than the city’s typical 50-foot standard for many streams.

Why it matters: adopting the site-potential-height model without adjustments could “quadruple and almost quintuple buffer widths” over much of the city, Levitan said, a change that would reduce available buildable land and could require revisiting growth targets in the comprehensive plan. Staff said they are consulting with WDFW and looking at alternative analyses that document whether a smaller buffer can still achieve most ecological functions.

Key points from staff and commissioners

- Levitan said the consultant’s gaps analysis found the city largely compliant but identified items needing clarification and updates; frequently flooded areas and geologically hazardous areas need only minor revisions, while wetlands and riparian rules warrant more attention. Senior Planner Amber Brokenshire joined Levitan on the presentation and the technical packets in the commission’s materials.

- Under the WDFW model, a tree with a 235-foot potential height would suggest a 235-foot buffer. Staff said administering that strict model across most of the city would be impractical and that WDFW has shown flexibility in some jurisdictions by accepting alternative analyses that document preservation of core riparian functions.

- Staff described an example alternative: establishing a 100-foot minimum buffer in many areas could achieve roughly 88–95% of the ecological functions identified in the science, while preserving more land for housing and employment. Fish-bearing streams currently receiving 100-foot minimums might be increased to 150 feet under some recommendations; ephemeral and non–fish-bearing streams (many now at 50 feet) are the area of greatest change under the model.

- Commissioners asked about nearby jurisdictions’ progress; Levitan cited Mountlake Terrace as further along, Marysville at a similar stage, and said staff are in contact with other planners. Staff noted coordination with public works’ basin planning and with the surface water team to identify enhancement projects that could be used in trade-off arguments with WDFW.

- Several commissioners expressed concern about impacts on existing neighborhoods and businesses, and asked how redevelopment of previously disturbed lots would be treated. Levitan said the draft approach would retain allowances to rebuild within disturbed footprints and that the code would include exceptions for predeveloped areas; further detail will be drafted for public review.

Staff direction and next steps

Staff said they will pursue an alternative-evaluation strategy with WDFW, coordinate with neighboring jurisdictions and the county, and overlay riparian management zones with the city’s buildable-lands mapping to identify where large buffers would most affect development capacity. Levitan told the commission the city would prepare proposed code language and return to the commission before public hearings, and that staff plan to brief the city council next month.

Ending

Commissioners generally expressed alignment with staff’s direction to seek a balanced approach that preserves core riparian functions while limiting impacts on the city’s capacity for housing and employment. Levitan said the city will continue technical coordination with WDFW and other jurisdictions and will bring detailed code language back to the commission in the coming months.