By Madeleine Voth
Most Portlanders pass them without a second thought, but green street planters are hard at work across the city, especially in SE, where dense housing, aging infrastructure and busy corridors often collide.
Planted between sidewalks and roadways, these curbside gardens do more than simply add greenery. They are part of Portland’s Green Streets Program, a citywide effort led by the Bureau of Environmental Services (BES) to manage stormwater naturally while supporting neighborhood livability and environmental health.
Green Streets—often called rain gardens or bioswales—are landscaped facilities that use plants and soil to slow, filter and absorb stormwater runoff from streets and sidewalks before it enters the sewer system. Unlike traditional stormwater management, which quickly pushes runoff into pipes, Green Streets manage water closer to where it falls using natural processes. They are designed to keep runoff out of the sewer system and reduce pollution in Portland’s rivers.
Such an approach matters in SE Portland, where the impacts of heavy rainfall show up as street flooding, burdened sewer capacity and, at times, sewer backups that affect residents. According to Andy Kiemen, Senior Communications Representative at BES, by keeping stormwater out of the combined system, Green Streets preserve local system capacity (important for reducing sewer backups) while supporting other goals: reducing overflows, preventing pollution, improving water quality and adding green space to the urban environment.
Because not every street can accommodate a planter, Kiemen says locations are prioritized through system modeling, risk assessment and input from BES staff, the overarching goal being to place Green Streets where they can reduce stormwater entering the sewer system, protect water quality in nearby waterways and lower the risk of sewer backups affecting properties. In SE Portland, Green Streets frequently show up in places where stormwater concerns overlap with walking and biking routes. Portland’s neighborhood greenways are low-traffic, low-speed streets intended to prioritize walking, bicycling and rolling.
Even so, a Green Street planter is only as effective as the condition in which it is maintained. Kiemen says maintenance crews visit Green Streets as needed, at least twice a year, to remove sediment, leaves or trash that block flow into the planter; to prune or replace plants and remove weeds; and water new plants until they are fine on their own.
Within this, Kiemen shared several challenges that are especially relevant in high-use corridors: keeping plants alive through increasingly hotter, drier summers; vandalism or damage to plants or structures; foot traffic that tramples plants and compacts soil; and heavy sediment buildup on high-traffic streets. To respond, BES says it is adapting soil mixes and plant palettes to be more climate-resilient and using inspection data to prioritize maintenance, retrofits and rehabilitation.
Kiemen says that BES has conducted extensive performance monitoring of stormwater facilities and has a strong sense that Green Streets, when in good condition, do what they were designed to do: control stormwater flows, retain stormwater and improve water quality.
On the maintenance side, BES invites residents to become Green Streets Stewards—volunteers who “adopt” a planter and help care for it between city maintenance visits. Stewards can pick up trash, remove sediment and debris so water can flow and water plants during dry summer weather. With BES approval, stewards may also weed established planters (at least two years old) and add plants or flowers. BES notes that participation can provide community service credit for students, support neighborhood cleanups and give residents exercise and a way to beautify their street while improving water quality.
Kiemen frames Green Streets as one piece of Portland’s broader climate mitigation, resiliency and adaptation strategy as the city faces hotter, drier summers, more intense rainstorms and increased flood risk. The bureau says it is upgrading infrastructure, integrating climate projections into design standards and investing in floodplain restoration and other nature-based solutions to protect vulnerable communities, habitat and wildlife. BES also notes its Green Streets maintenance program is currently funded through the Portland Clean Energy Community Benefits Fund (PCEF).
BES does not set a numeric citywide goal for how many Green Streets will be built; construction varies year to year, as Green Streets come both through capital-funded public projects and through private development requirements influenced by budget cycles, project prioritization, grants and economic allowances.
For many Portlanders, Green Streets may not be noticed at first glance, but these planters form a growing network of green infrastructure and transform city streets in SE Portland and beyond, one block at a time.
If you have an issue with Green Streets planter in your area, you can report a Green Streets planter concern at portland.gov/bes/report-green-street-planter-concern. If you’re interested in getting involved, you can become a Green Streets Steward through the above link.
Green Streets planter after heavy rainfall. Photo by City of Portland.
