Snoqualmie outlines new NPDES stormwater requirements and targets Kimball Creek retrofits by 2028

Project engineer Patrick Fry briefed the Snoqualmie Parks and Public Works Committee on May 6, 2025 about the 2024–2029 NPDES municipal stormwater (MS4) permit cycle and new work required under the Department of Ecology permit, including a large new component for stormwater management of existing development.

The briefing matters because the new permit items add staff workload and capital obligations for the city, including a behavior-change social marketing campaign, expanded business inspections, a municipal street sweeping program, mapping of MS4 outfalls and a requirement to implement or fully fund stormwater retrofit projects equal to 2.3 equivalent acres in the Kimball Creek priority catchment by 2028.

Patrick Fry, project engineer for the City of Snoqualmie, outlined 2024 compliance work and new permit milestones. For 2024, Fry said staff inspected about 1,500 catch basins and cleaned 406, inspected all 62 city-owned stormwater facilities and performed maintenance on 37 of them, reviewed 12 site plans, inspected two construction sites, performed 27 business inspections that produced two corrective action letters, and received roughly $135,000 in grants for stormwater work.

Fry summarized core recurring permit components—public education and outreach, public involvement, system mapping, illicit-discharge detection and elimination, plan review for new development and construction-site inspections, source control inspections of private businesses, and operation and maintenance of city-owned stormwater facilities. Under the new permit cycle, the city must field-screen 12% of its MS4 annually, inspect 20% of regulated businesses and inspect a portion of its roughly 3,100 catch basins on a rotating schedule (Fry said this equates to about 400 catch basins per year on average for required cleaning checks).

Fry highlighted new and resource-intensive items. In 2025 the city must develop and implement a social marketing (behavior-change) campaign informed by the 2024 evaluation; Fry said the campaign requires measurable behavior-change goals, public events and consultant support to track outcomes. For 2026 the city must submit locations of all MS4 outfalls, begin identifying tree canopy, and document outreach methods for identifying overburdened communities. Fry read a permit definition for overburdened communities, explaining it designates geographic areas where populations face multiple environmental harms and health risks and may have socioeconomic barriers to participation in planning.

Fry said 2027 carries several major tasks: procedures to reduce PFAS from firefighting discharges (the city said its fire department already avoids PFAS-containing firefighting foam), tracking permit implementation costs, coordination with long-range planning updates, an updated stormwater management action plan (SMAP) or a new plan for a priority catchment, and the implementation of a municipal street sweeping program. Fry noted the city started in-house street sweeping the day before the presentation, reducing the anticipated lift in 2027.

Fry described the SMED (stormwater management for existing development) as the largest new ask in the 2024–2029 cycle. The city must, by 2028, fully fund, start construction on, or complete projects that meet an assigned 2.3 equivalent-acre target in the Kimball Creek catchment area. Fry explained that the “equivalent acreage” calculation translates different retrofit types (for example, a filter cartridge serving a given drainage area) into a common metric used by Ecology for compliance reporting. He told the committee Kimball Creek was chosen because it is a relatively polluted catchment with opportunities for cost-effective retrofit projects; Fry observed, “That’s why when it floods, you see, like, toilet seats floating down Kimball Creek,” to illustrate local flooding and debris problems.

Fry said the Kimball Creek repair and restoration project in the city’s capital improvement program (CIP) is intended to cover the cost of the SMED-required work. Committee members asked whether general education and business outreach would continue; Fry said general awareness campaigns are ongoing yearly, while the behavior-change social marketing campaign is a separate, more resource-intensive requirement that will need consultant support and measurable goals.

Next steps: city staff will continue mapping and planning tasks, begin the social marketing procurement, advance the Kimball Creek CIP projects to meet the 2.3 equivalent-acre requirement, and report progress in subsequent permit-year filings to Ecology.