Shoreline staff propose ESU stormwater rate structure and $3,585 general facilities charge; council asks for implementation details

Shoreline City Council on Monday discussed proposed changes to the city’s surface-water rates and a new general facilities charge (GFC) intended to align stormwater fees with the amount of hard surface on a parcel and to require new development to pay a share of system capital costs.

John Featherstone, surface water and wastewater systems manager, and Taghi Aaker from FCS Group briefed the council on two linked proposals: convert the current seven-tier hard-surface billing system to an Equivalent Service Unit (ESU) charge (one ESU defined as roughly 2,600 square feet of hard surface) and adopt a new surface-water GFC calculated at $3,585 per ESU.

Why it matters: the ESU model charges parcels proportionally based on hard surface area rather than flat tiers; the GFC is a one-time charge assessed on new development to help fund existing and planned capital projects so growth pays for growth. Together the policies affect residential, commercial and redevelopment projects and the city’s capital funding strategy for stormwater infrastructure.

FCS presented the methodology and examples. Using updated aerial data the consultant estimated a 2027 fee per ESU of about $440.15 to meet the forecasted revenue requirement (roughly $12.8 million in 2027). FCS showed examples where a commercial bank parcel would see a modest increase under ESU billing while a large impervious facility (a transfer-station-type site) would pay less than under the existing tiered structure.

For the GFC, the consultant summed existing capital costs (about $39 million) and planned future projects (about $78 million), divided that total by estimated system capacity and calculated a defensible maximum GFC of $3,585 per ESU. Staff recommended adopting the full calculated GFC but noted the council could elect to phase in or adopt a lower charge.

Staff outlined implementation steps and timing. Before converting billing systems Shoreline will audit and update hard-surface aerial data, define and rename the residential billing class to reflect middle-housing and new zoning, develop clear class criteria, and coordinate with King County (the city’s billing provider) to implement ESU billing for 2027 billings. For the GFC, Shoreline will adopt a code amendment, create a formal policy, develop permitting processes to assess and collect fees, and provide public notice to developers and property owners.

Council questions touched on equity and housing. Councilmember Adamaso urged that the GFC exemption threshold for very small projects (staff discussed a threshold under half an ESU or 1,300 square feet) apply equally to small residential projects — for example modest ADUs — to avoid disincentivizing affordable housing. Deputy Mayor Mark asked about permeable pavement and staff said the city counts permeable pavement as hard surface for billing because its performance depends on maintenance. Councilmember Ramsdale and others praised the clarity and urged the city to update ESU definitions as redevelopment occurs.

Staff also reported an early success for program expansion: a “Soak It Up” rebate program expansion generated more applications and site visits than expected in the first weeks after the increase in rebates, indicating strong customer interest in onsite stormwater measures.

No ordinance was adopted Monday; staff requested council input on implementation steps and said they plan to return with a final Surface Water Master Plan and implementation schedule in early summer and to target 2027 for ESU billing and GFC collection, subject to completing code amendments and billing-system changes.