Wednesday, April 22, 2020
How to Contain Stormwater using Green Infrastructure
By Bonnie Jean Feldkamp
Northern Kentucky's Sanitation District [SD1] sees more than 1 billion gallons annually of combined sewer overflows (storm and sanitary). Northern Kentucky operates with an outdated stormwater system and the community is left with sewers that overflow into streets and basements after a hard rain.
When more than a quarter inch of rain is predicted, SD1 notifies residents in its service area via their Wet Weather Notification Program to avoid direct contact with local waterways and the pathogens flowing through them. Residents can request to be on that mailing list here.
Though SD1 continues to update the sewer system, that takes time. The current estimate for completion is 2040. In the meantime, residents can help reduce the negative effects of an inadequate sewer system on their own property by implementing green infrastructure practices. Since Wednesday, April 22 is Earth Day and spring rain is here, it's the perfect time to talk about what we can do at home.
The ultimate goal of green infrastructure is to keep rainwater as close to where it falls as possible. When a neighborhood lacks greenspace, water can't get absorbed and it overwhelms the wastewater collection system. Many older river cities have an outdated infrastructure.
Let's go through how to mitigate this issue one-by-one below:
Depaving isn't as simple as getting rid of pavement and replacing it with greenery. It's important when taking on a depaving project that part of the strategy is understanding the history of the property and testing for contaminants. It doesn't have to stop the project, but it will inform how the space is used.
A 2010 study conducted in the European Union took a comprehensive look at the most commonly used pavements and showed that where a sealed asphalt surface provides zero stormwater absorption, an unpaved surface provides 90% absorption.
Depaving doesn't have to mean pulling up concrete in an abandoned lot. Switching from conventional asphalt to porous asphalt on a driveway can reduce imperviousness by as much as 50%.
Rain barrels collect water from rooftops and store it for later use in gardens, lawns or even indoor plants. A drip line on a rain barrel also helps slowly release the collected water for better absorption. This not only reduces stormwater overload but also reduces water costs during dry spells.
Rain gardens can be helpful if the property has a low spot that tends to pool or sludge during rain events. A rain garden is designed to intercept rainwater and slow it down.
Campbell County, offers residents financial assistance when implementing conservation practices in their own backyards. You can find that Cost Share information here.
I utilized this program to install the rain barrels at my house. But the program also provides assistance with planting pollinator gardens, building raised garden beds, as well as other backyard garden projects.
Planting trees is vital to the urban landscape. Water is intercepted on tree leaves and bark surfaces, and trees suck it up from the soil. Trees also improve infiltration of water into the soil and clean the air.
A newly planted tree, one you can carry around, won't do much in the beginning but, by the time it's 20 years old, it will do a good amount of stormwater management. Existing trees should be taken care of before planting new ones.
Fort Thomas has a Tree Commission that takes a special interest in the city's Landmark Trees. If you have a tree care question about one of your trees contact them here.
Online tools such as Mytree.itreetools.org can provide data, such as how much water has been intercepted and how much runoff has been avoided. For example, an oak tree about 17 inches in diameter can intercept 1,800 gallons of water per year.
For Earth Day, I encourage you to look for ways you can help both your property and the Earth.
Information in this article is an excerpted from an article Bonnie Jean Feldkamp originally wrote for Good River: Stories of the Ohio, a series about the environment, economy, and culture of the Ohio River watershed, produced by seven nonprofit newsrooms. To see more, please visit ohiowatershed.org. Visit eyeonohio.com for more from the Ohio Center for Investigative Journalism.