Keeping a pulse on stormwater trends: the future is GSI

Posted in: Municipal, Water

Urban runoff visibly impaired by oil and grease. Other pollutants are not as easily identifiable but still present in urban runoff.

The approach to stormwater management has shifted. Now, instead of viewing stormwater as a nuisance to be conveyed away as quickly as possible, it is seen as a potential benefit, with more consideration of source control, treatment and reuse. Despite this general shift, urban stormwater remains a growing source of water pollution as population and urban areas expand. As water resources engineers, it is important to keep a pulse on current drivers and trends in the industry. This way, we can better supply our communities with safe and reliable water infrastructure.

The world of water management is constantly changing. Constituents of emerging concern remain on the radar, requiring various source controls and treatment methodologies to prevent environmental harm. Climate change has altered rainfall frequency and intensity, which means our solutions need to be more resilient. Green infrastructure practices continue to gain ground, leading to code modifications, new maintenance practices, and community support—along with healthier, livable communities and environs. With so many changes, it can feel difficult to keep up with it all.

Rain gardens are a type of GSI that capture urban runoff and provide filtration through soil and plants.

Getting involved in professional organizations and networking with peers is an effective way to keep apprised of current industry drivers and trends. The Washington Stormwater Center is studying the toxicology of stormwater runoff and the biological effectiveness of green stormwater infrastructure (GSI). At the 2019 Stormwater Summit hosted by the Oregon Association of Clean Water Agencies, John Stark, PhD, Director of the Washington Stormwater Center, shared recent findings from their research group covering types of pollutants found in urban stormwater and their effects on various aquatic organisms.

This research revealed that materials leached from car tires into receiving waters negatively impacted the mortality and sterilization of multiple aquatic species. GSI, such as rain gardens, are effective in reducing these pollutants that runoff from paved areas prior to discharge to receiving waters. However, GSI is land intensive. Other options evaluated include compost amended bio-swales and permeable pavement with carbon fibers.

Depave volunteers remove a large slab of asphalt pavement making way for a rain garden.

Another professional organization keeping a finger on the pulse of the water world is Pacific Northwest Clean Water Agencies (PNCWA). The organization focuses on clean water projects across Idaho, Oregon and Washington. On September 8, 2019, the PNCWA Stormwater Committee will be hosting a service project in East Portland in conjunction with the Depave organization. Depave “promotes the transformation of over-paved places to overcome the social and environmental impacts of pavement.” At the event, asphalt pavement will be removed in preparation for fall planting of a GSI rain garden as part of a larger Depave project. The Stormwater Committee members and Depave will provide educational materials about the benefits of removing pavement and implementing green infrastructure.

We look forward to PNCWA members joining other community members for this event. Looking at where the stormwater industry is headed overall, all signs point to one thing: GSI. Green infrastructure is a vital part of building safer, healthier communities that will thrive for generations to come.

Kari Nichols, PE

About the Author

If a raindrop falls on the project, Kari Nichols, P.E., gets involved to find a stormwater management solution. “I believe in dedication and follow-through,” she says. “Deciphering regulatory language and developing workable design solutions helps me connect with clients and colleagues.” Kari has a taste for adventure and a passion for sustainability, which she satisfies by exploring natural and urban environments.

Read more posts by Kari Nichols, PE

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