Flooding and Green Infrastructure in the Town of Tewksbury

Flooding is defined as "the covering or submerging of normally dry land with a large amount of water". Often this is from excess water that collects is low lying areas during and after rainstorms.

We all have our own idea of what we consider flooding. A wetland with standing water is natural, but standing water in your backyard or basement might be flooding. A puddle in the road might be annoying when you're in a car, but when it means you can't walk to your work or home, it could be flooding.

The key is - when excess stormwater becomes problematic for our way of life, we typically call it flooding. These are the areas where flooding has the biggest impact on our lives. When excess water is in an area that is not used by humans, we typically don't mind - or even notice - that it's there. In natural areas, flooding is often beneficial since it creates important habitat for various species of animals, plants, and amphibians.

Flooding is excess water that exists after it rains, but can be problematic or beneficial depending on how it impacts our lives

Continue scrolling to view the natural features and historical changes that contribute towards flooding in Tewksbury today.

We're already experiencing flooding under current conditions, and it's only expected to get worse under climate change. For Massachusetts, it's estimated that there will be a 10% increase in the annual precipitation, but the rainstorms will also become more intense and frequent. This means the infrastructure in Tewksbury needs to be prepared to handle more water in a shorter period of time. Take a look at the infographics below to better understand how rainfall has already changed over the past few decades, and what we predict the conditions will be in the future.

Because Tewksbury is located in a naturally wet area and climate change is expected to bring even more rain, eliminating flooding is impossible. However, there are still things we can do to manage excess stormwater so that it doesn't impact our lifestyle.

One of the best things to do is learn from nature. Green infrastructure is a way of understanding how nature manages stormwater and then mimicking these processes in our built environment.

When it rains in natural areas, water gets absorbed into the soil, acting as a natural storage area. The rest of the water flows slowly over the ground and into a waterway, like a stream or river. When these waterways get too full, they overflow onto their floodplains, creating another natural storage area. This flooded area also creates important habitat for aquatic plant and animal species.

When impervious surfaces are created (like paved roads and parking lots), the rainwater can no longer reach the soil and will runoff quickly into a waterway. This will cause more water to go into the river and increase the amount of water in the floodplain. In addition, when we build roads and buildings in these floodplains, they will also become flooded and can cause problems for people living and working in those areas.

By using green infrastructure techniques, we can minimize flooding and control where it happens.

One main principle of green infrastructures is minimizing the area of impervious surfaces in order to let water infiltrate into the soil. This will help to prevent runoff and reduce localized flooding. Where impervious surfaces must remain, stormwater can be diverted into areas that are flooded on purpose, similar to the way a river floodplain works.

Flip through the slides from the US EPA below to learn about different types of green infrastructure elements. Not only does green infrastructure help reduce flooding, but it also has other benefits like providing shade, filtering water to improve water quality, providing green spaces, improving air quality, and more.

Tewksbury already has some green infrastructure, and plans to develop more! Continue scrolling to learn about current and potential new green infrastructure.

Green infrastructure is both functional and attractive. In addition to managing flooding, it can make streets greener, increase shade, improve air quality, improve water quality in streams and rivers, provide space for recreational use, and more!

Below are three renderings of potential green infrastructure improvements in Tewksbury. These are only examples, but can provide a great idea of what is possible!

Click below to read the full report on proposed solutions.

So glad you asked! Green infrastructure doesn't have to be highly engineered, expensive or a project that only the town takes on. You too can manage excess stormwater in your own yard!

Learn how to manage stormwater on your property

Stormwater can have a big impact on your property, and properly managing it can help prevent localized flooding as well as improve local waterways and ecosystems. This  guide from the Lancaster Country Conservation District in Pennsylvania will give you step-by-step instructions  on how to assess how much runoff is being generated on your property, understand how stormwater moves across your property, and then tips to build and implement a stormwater management plan.

Build a rain garden

Rain gardens are attractive, functional landscaped areas designed to capture and filter stormwater before it runs off into storm drains. They collect water in natural or constructed shallow vegetated depressions and allow it to soak into the ground slowly.

The UMass Extension Landscape, Nursery and Urban Forestry Program can help you understand how to  plan, install, and maintain a rain garden on your property .

Install a rain barrel

Rain barrels are containers used to collect rain water from the roof of a building via the gutter and downspout, preventing pollutants from ending up in local waterways as well as capturing water to prevent localized flooding. Keeping and using rain water on your property helps reduce pollution and erosion and improves local watershed health.

The Massachusetts Department of Environmental Protections has resources on  what rain barrels are and how to install them .

Install a downspout planter

A downspout planter is similar to a rain barrel, but instead of storing the water for later use for irrigation, the water goes directly into a planter.

The City of Philadelphia  has a guide to design and construct a downspout planter .

Replace your driveway with permeable pavement.

Permeable pavement allows water to infiltrate into the soil, rather than run off.

You can learn more about permeable pavement from the  EPA  and  MassDEP. 

Thank you for visiting this StoryMap to learn about flooding in Tewksbury and green infrastructure as a solution. We hope you learned something new!

This StoryMap was developed as a part of a Municipal Vulnerability Preparedness (MVP) grant received by the Town of Tewksbury in partnership with the Merrimack River Watershed Council and Weston and Sampson. Created in 2017 as part of Governor Baker’s Executive Order 569, the MVP program pairs local leadership and knowledge with a significant investment of resources and funding from the Commonwealth to address ongoing climate change impacts like sea level rise, inland flooding, storms, and extreme temperatures.

If you have any questions about the project or the content provided here, please email susie@merrimack.org.