Newberg engineers caution that curb‑tight sidewalks complicate stormwater treatment; council leaves option as exception

Newberg leaders heard technical advice on Nov. 3 about whether the city should allow "curb‑tight" sidewalks — sidewalks built directly at the curbline without the typical planting strip — as part of updated typical street cross sections.

Keller Associates acting city engineer Travis Smith and design lead TJ Centanni told the joint City Council–Planning Commission work session that Oregon statutes do not prohibit curb‑tight sidewalks, but state stormwater treatment standards administered by the Department of Environmental Quality mean curb‑tight sections require additional localized or regional pretreatment before stormwater can be discharged to the storm system. Centanni said those requirements make curb‑tight sidewalks more complicated to build and to maintain than separated sidewalks with planter strips.

Why it matters: planter strips behind the curb serve multiple functions (stormwater pretreatment space, a buffer that increases pedestrian safety, space for street trees, lighting and furnishings, and room for gentler ADA ramp transitions). Keller presented two basic compliance approaches: 1) provide localized treatment within the planter or in a trench drain behind a curb‑tight sidewalk; or 2) route runoff to a regional…