Lessons Learned from Five Years of Monitoring the Barton Combined Sewer Overflow (CSO) Green Streets
Start Date
3-16-2026 1:50 PM
End Date
3-16-2026 1:59 PM
Abstract
This project evaluated the condition of vegetation within the Barton Combined Sewer Overflow (CSO) Green Stormwater Infrastructure (GSI) project located in the Roxhill neighborhood of West Seattle. Initial evaluations reviewed deficiencies in plant performance with the goal of performing retrofit planting designs to reduce long-term maintenance and after planting, conducting post retrofit and control block monitoring. Monitoring occurred in spring and fall for a period of 5 consecutive years, from 2021 to 2025, and this presentation will share the results of this unique experience collecting detailed data over multiple years.
The summary data shows which tree species maintained health over time and which species died and required replacement. The data also shows which plants achieved dominant cover during spring and fall seasons as facilities mature. Data also shows a correlation between weed control activities and vegetation cover for desired species and the need and effectiveness of retrofit planting over the life cycle of stormwater facilities as an adaptive management strategy.
Monitoring also resulted in a series of follow-up questions regarding our expectations for the life cycle performance of vegetation in stormwater facilities and some ideas about how municipalities can further reduce the maintenance burden of vegetation while maintaining biodiversity, aesthetics, and community value.
Subjects
Plant ecology, Sustainable development, Water quality
Creative Commons License
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Lessons Learned from Five Years of Monitoring the Barton Combined Sewer Overflow (CSO) Green Streets
This project evaluated the condition of vegetation within the Barton Combined Sewer Overflow (CSO) Green Stormwater Infrastructure (GSI) project located in the Roxhill neighborhood of West Seattle. Initial evaluations reviewed deficiencies in plant performance with the goal of performing retrofit planting designs to reduce long-term maintenance and after planting, conducting post retrofit and control block monitoring. Monitoring occurred in spring and fall for a period of 5 consecutive years, from 2021 to 2025, and this presentation will share the results of this unique experience collecting detailed data over multiple years.
The summary data shows which tree species maintained health over time and which species died and required replacement. The data also shows which plants achieved dominant cover during spring and fall seasons as facilities mature. Data also shows a correlation between weed control activities and vegetation cover for desired species and the need and effectiveness of retrofit planting over the life cycle of stormwater facilities as an adaptive management strategy.
Monitoring also resulted in a series of follow-up questions regarding our expectations for the life cycle performance of vegetation in stormwater facilities and some ideas about how municipalities can further reduce the maintenance burden of vegetation while maintaining biodiversity, aesthetics, and community value.