Green Roofs and Urban Heat Island Prevention
Have you ever walked around your city during a hot summer day and wondered why it feels warmer than the surrounding countryside? The answer is the urban heat island effect, which is a phenomenon that occurs when cities are significantly warmer than their surrounding rural areas. Heat islands can cause serious health and environmental problems. Fortunately, there are ways communities can reduce the heat island effect, one is through the installation of green roofs. In this blog post, we will discuss how green roofs can help prevent and mitigate the urban heat island effect in Norwalk, CT.
What is the urban heat island effect?
The urban heat island effect is caused by the large amount of asphalt, concrete, and buildings that absorb and radiate heat in urban areas. As a result, cities can be up to 10°F warmer than the surrounding rural areas. The heat islands can increase energy consumption, air pollution, and greenhouse gas emissions, and they can also have a significant impact on human health, particularly for vulnerable populations like the elderly and children.
How can green roofs help prevent the urban heat island effect?
Green roofs are roofs that are covered with vegetation, soil, and other materials that protect the building from the elements and help regulate temperature. Green roofs can lower the temperature of the building and the surrounding area by absorbing and promoting the evapotranspiration of water, and reducing the amount of heat absorbed by the building. In addition, green roofs can absorb air pollutants, reduce greenhouse gas emissions, and provide a habitat for a variety of plant and animal species.
Read about Norwalk, CT’s Street Canopy Project
How are green roofs installed or added to structures?
Installing green roofs is easier than you might think. Local building codes and zoning regulations may require a certain percentage of green roofs for new construction, retrofitting, and renovation projects. Moreover, there are several companies in the area that specialize in green roofing and can help you install and maintain a green roof. Green roofs require proper planning, irrigation, and maintenance, but they are an excellent investment for homeowners, businesses, and communities that want to reduce energy costs, improve air quality, and promote sustainability.
What are the benefits of green roofs, beyond reducing the urban heat island effect?
Green roofs have numerous benefits that go beyond mitigating the urban heat island effect. For instance, they can improve stormwater management by reducing runoff and preventing flooding. They can also enhance the aesthetic value of buildings and create new green spaces for people to enjoy. Green roofs can even improve the value of the property by increasing its energy efficiency and ecological footprint. Green roofs are one tool communities can implement to reduct the urban heat island effect. They can help reduce energy consumption, air pollution, and greenhouse gas emissions, while also providing numerous other benefits.
Green Roofs in Norwalk, CT
Norwalk is implementing new zoning regulations in early 2024 which will require a Green, Blue, or Solar-equipped rooftop in some cases. Other zones will offer development bonuses for projects that include Blue, Green, or Solar-equipped roofs as well as other sustainability measures. If you are a homeowner, a business owner, or a community leader in Norwalk, CT, consider installing a green roof on your property and contributing to a more sustainable and healthy environment.
Let's work together to promote green infrastructure and make our city a better place to live, work, and play.
Preserving Norwalk’s Trees: Norwalk, CT's Street Canopy Project
Trees provide habitats and improve the air we breathe. They help mitigate storm water, give us shade and project a sense of calmness in the world. Trees beautify both suburban and urban areas and can help reduce the heat island effect.
Many states and cities are looking at ways to protect their trees by coming up with a more enlightened approach to preserving current trees and planting new ones. The question is, how can cities continue to develop and maintain the tree cover in the process?
In Norwalk’s Citywide Plan, the City is tasked with protecting the natural environment. This entails not only protecting the open spaces and parks, but also its urban forestry by balancing growth and preservation. Allocating roadside space to street trees and landscaping helps improve the aesthetics of the streetscape, provides a buffer between the roadway and sidewalk to improve pedestrian comfort, and can facilitate stormwater management through bioretention features such as planters and swales.
Below we take a look at how Norwalk, CT is working to enhance its tree canopy with a tree ordinance and other actions.
Norwalk's History of Tree Planting
Keeping Norwalk a tree-laden city has long been important to Norwalk. The city has had a tree planting program and a tree management plan in place for over 18 years. Key to this plan is working with liaisons from neighborhood associations. The liaisons keep an eye on all things tree-related in their area and suggest tree plantings in an effort to increase the number of trees in the city.
This approach ensures that the public has oversight and input into keeping a tree canopy alive and vital in their neighborhoods. Since 2004, about 1,200 trees have been planted in the city.
Norwalk Tree Ordinance
In Norwalk, like most cities, the more urban neighborhoods have fewer trees. Consequently, low-income neighborhoods have less tree canopy coverage, resulting in health and environmental problems such as high asthma rates.
To protect the City’s existing trees, and increase Norwalk's tree canopy equitably, the Common Council approved an updated Tree Ordinance in 2021. It gave the city's tree warden expanded powers and established a legacy tree program.
The tree warden is tasked with assessing or overseeing the evaluation of the city's tree canopy. This evaluation helps determine whether or not a tree may be removed or altered when it’s on public property. To do so, requires a permit from the warden. The warden may also require a tree or shrub be replaced.
The warden keeps a record of the city's existing trees, creating a catalog of the important legacy trees according to their size, age, and species.
The ordinance requires developers to protect a tree’s root zone during construction. The developer will also pay a bond before any work begins. Fines and penalties aim to discourage the unnecessary removal of trees.
Another important change brought about by the Tree Ordinance is the establishment of a Norwalk Tree Account. This account helps fund tree planting with the use of tree-related fines and fees, and other payments as well as public and private grants. Since its establishment, grants to this account have increased, allowing the City to expand its tree planting. For example, since the Tree Ordinance was passed, tree plantings increased from 56 in the fall of 2020 to 171 in the spring of 2022.
The Tree Advisory Committee
In the 2021 Tree Ordinance, the duties of the Tree Advisory Committee expanded. The Committee works closely with the tree warden to recommend the types of trees to plant. They also encourage Norwalk residents to volunteer to help plant trees as part of the ongoing tree planting program.
The Committee will oversee the creation of a Master Tree Plan which will include any studies made by the tree warden. The plan will assess Norwalk’s current tree canopy along with the relevant environmental, social and public health benefits, and develop strategies and actions to increase tree cover with primarily native and hybrid species of trees.
Norwalk, CT's Environmental Projects
Concerns about environmental protection in Norwalk have led to the commitment to protect and increase Norwalk's tree canopy including urban trees throughout the city.
The city is also undertaking a heat sensor study to track temperatures in various parts of the city to identify areas that may be vulnerable to extreme heat events. The results from this study will help inform tree planting and illustrate the benefits of a tree canopy.
In addition, Norwalk is in the process of adopting Complete Streets legislation and design manual. These will provide guidance for designing and reconstructing our streets with the principles of safety, sustainability, and vitality. This comprehensive and cross-functional approach to maintaining and designing the public right of way will take into consideration new tree installations.
Environmental projects like the Norwalk Tree Plan and Tree Ordinance recognize that trees are an integral part of a healthy ecosystem, sequestering carbon, reducing stormwater, and improving the health and well being of residents.
Environmental Resilience Planning: Heat Study in Norwalk, CT
High temperatures can harm people and the environment. In the U.S., more than 67,000 people each year go to emergency rooms due to heat-related symptoms. With climate change, heat waves are expected to only become more frequent and severe.
Learning how climate change affects our communities and how we can plan for it is critical. In Norwalk, Connecticut a study is currently being conducted to track changes in the air and surface temperatures to see how it may affect the city and its residents.
Keep reading to learn more about the heat study in Norwalk, CT.
Why is Norwalk Conducting a Heat Study?
During hot periods, people in urban areas experience higher temperatures than rural areas. More asphalt, higher concentration of buildings and fewer trees make cities retain more heat. This is called the Urban Heat Island Effect.
Being from a temperate area, most Connecticut residents aren’t accustomed to extreme heat. As a result, area residents face a heightened risk for heat-related illnesses during times of extremely high temperatures. Studies suggest that climate change will intensify the conditions that lead to heat-related illnesses, symptoms that can even prove fatal.
Norwalk has also been found a vulnerable zone by the Connecticut Institute for Resilience and Climate Adaptation (CIRCA) in a recent Vulnerability Assessment. To prepare, Norwalk is partnering with CIRCA on resiliency projects. The heat study is part of that, and will look at changes in air and surface temperatures over time.
Norwalk, CT Heat Vulnerability Assessment
The Goals of the Heat Study
The primary goal of the heat study is to find and map various areas in Norwalk to understand the vulnerabilities of different areas to heat. This will help the city identify at-risk areas in order to develop ways to help the community prepare for higher, more extreme temperatures, like where to place cooling centers. The study will also take a look at urbanization and rising temperatures, such as understanding how certain traffic flows affect heat output in order to put in place effective solutions to combat climate change.
The data revealed by the study will also enable researchers to model inconsistencies and examine the differences between heat sensors and satellite-measured temperatures.
How the Heat Study in Norwalk, CT Will Work
To gauge temperatures in the city, heat sensors have been placed at 13 locations around Norwalk, from Long Island Sound shorelines and parks to buildings in more urban areas. The study is being conducted from June through October 2022.
The sensors are wireless, and are mounted 8-10 feet above ground on trees or poles. They will measure and monitor temperatures and relative humidity. They will also record dew point temperatures at the street level.
Learn More, Get Involved
The heat study in Norwalk will help find areas of the city that are vulnerable to extreme heat events to inform decisions related to public health and community planning in the years to come, including the development of a community-wide resilience plan. You can find more information at the CIRCA Norwalk Heat Study page. In the near term, the heat study will help to guide the Resilient South Norwalk Project launching in the summer of 2022 with CIRCA.