What is Green Infrastructure?
Humans have had such a profound impact on the world around us that the modern age has been dubbed the Anthropocene — "The Age of Humans" — a period in which human activity has been the dominant force influencing the environment and climate.
The increasing amounts of energy and materials required to sustain current consumption levels are a danger to the environment as we know. Pollution and waste are damaging water and air quality, altering the climate on a global scale. As the global population continues to grow, more people are moving to cities, and green spaces are disappearing.
Fortunately, many people have begun to take action to slow and reverse humankind's negative impact on the planet. Many are choosing to live more sustainably by biking to work, recycling and reducing their consumption levels. However, sustainable practices must also be implemented on a larger scale to truly reduce human impact on the environment. Landscape architects and developers can play an essential role by designing greener homes and planning greener cities.
The process of incorporating nature into architectural designs and city planning is called green infrastructure and is a crucial step toward a cleaner and healthier world. Green infrastructure can be implemented in a wide variety of ways that provide essential benefits for both humans and the planet.
Urban Green Infrastructure
Green infrastructure integrates plants and other natural elements to make urban spaces more sustainable and environmentally friendly. By tapping into the innate benefits of nature, green infrastructure can address a variety of problems, including water management, urban heat, pollution and climate change. For instance, green infrastructure in cities is often associated with stormwater management because pollution from stormwater runoff can be a major problem in urban areas.
Rainwater is typically carried through the city by drainage pipes then deposited into nearby bodies of water. As stormwater runs through the city, it collects bacteria, trash and other pollutants that contaminate the water. To be used again, that water must first be processed in a water filtration plant. Heavy rainfall can also cause flooding and erosion in urban areas with many impervious surfaces that prevent the absorption of water.
Green infrastructure provides a better way to manage stormwater by creating natural spaces where water can be absorbed into the earth and processed by plants and trees. When trees absorb water, they purify and release it back into the air as water vapor. This process, called evapotranspiration, provides cleaner air and better water quality. Urban green infrastructure can take the place of traditional grey infrastructure for water management, including replacing costly water filtration plants and drainage systems that carry pollution into waterways.
Another way that green infrastructure helps manage stormwater is by constructing wetlands that capture and treat rainwater. Wetlands can serve as a habitat for a range of species and improve water and soil quality. While stormwater management remains a major feature of green infrastructure, the term now includes a variety of environmentally beneficial infrastructure features. As concerns about climate change grow, many elements of green infrastructure are now directed toward reducing carbon dioxide (CO2) emissions or sequestering CO2 from the air.
Using natural elements to create cooler cities and buildings reduces energy usage, which then reduces the consumption of fossil fuels, a major source of atmospheric CO2. Trees are planted in cities can absorb and store CO2 from the air in a process called biosequestration, which reduces the volume of CO2 in the atmosphere.
Why Is Green Infrastructure Important?
Depending on the specific needs of a city or community, green infrastructure can be implemented in a wide variety of ways. Common types incude:
- Parks and urban forests: Creating green spaces in cities not only makes for beautiful features but also provides many environmental and health benefits. City planners can incorporate parks and forests into their designs to improve air and water quality, increase groundwater supply and provide outdoor recreation space.
- Forests and nature reserves: Just as parks are beneficial to cities, forests and nature reserves are beneficial on a broader scale. Large-scale green infrastructure looks at ways to preserve natural areas as well as rehabilitate existing forests and wilderness. Green infrastructure is concerned with creating policies for reforestation and protecting natural lands.
- Wetlands and constructed wetlands: Wetlands often serve as important borders or transitional environments between ecosystems. They can capture and purify water that's moving from an urban setting to a bay or ocean. Green infrastructure involves the protection and rehabilitation of existing wetlands as well as the construction of wetlands as part of a natural water management system.
- Bioswales and rain gardens:Green infrastructure often uses bioswales and rain gardens as a natural means of stormwater management. Bioswales are shallow linear basins typically built near large impervious surfaces such as roads and parking lots. These basins are filled with gravel or foliage that absorb, purify and slow the movement of the stormwater, which reduces the risk of flooding. Rain gardens are similar to bioswales except that they're often smaller and implemented in residential landscapes.
- Green transportation: Reducing the number of cars on the road is a great way to reduce the emission of CO2 and other harmful greenhouse gases. Green infrastructure can also include creating more mass transportation systems and making it easier for people to walk or bike around the city by adding bike lanes and paths.
- Green streets: A common environmental concern with cities is the creation of urban heat islands, which occurs when the temperature in a city is notably warmer than surrounding rural areas. Excessive urban heat can be due to a variety of issues, including pollution, greenhouse gas emission, more dark surfaces and buildings that reflect light. One way to help reduce urban heat is to creating green streets, which are lined by trees or other foliage that provides shade and reduces the amount of sun being absorbed by the road.
- Green roofs and walls: Another means of reducing urban heat is to grow plants or vines on roofs and walls. Green roofs often have a layer of dirt or gravel that also absorbs rainwater and reduces stormwater runoff.
- Wildlife habitats and corridors: Human developments such as cities and roadways often disrupt natural environments. Building wildlife corridors above roadways and providing wildlife habitats in and around cities connect natural habitats so that animals can move through human settlements freely and safely.
Why Choose Green Infrastructure?
Choosing green infrastructure has very real benefits for both humans and nature. It produces a cleaner and healthier environment, with many other societal perks. Additionally, while some environmental initiatives are stifled due to cost, green infrastructure is typically much more cost-efficient than traditional solutions to the same problems.
For example, managing stormwater through green infrastructure eliminates the need for costly water treatment plants and allows smaller drainage pipes to be constructed, which saves on overall project costs.
New York City invested in protecting water quality around its Catskills water reservoirs to avoid constructing and operating a costly water filtration plant. While they invested $600 million in water protection efforts, the water filtration plant would have cost $6 billion to construct and roughly $300 million to operate each year.
In Indianapolis, green infrastructure for water management allowed the city to reduce the diameter of a sewer pipe by several feet, saving over $300 million in material costs. When calculating the cost benefit of investing in green infrastructure, it's important to account for benefits such as improved public health and a cleaner environment. While these benefits may not have a tangible dollar value, poor health and environmental harm will lead to real costs down the road. Green infrastructure is often more cost-effective than traditional gray infrastructure while also providing numerous other advantages, making it a strong option to consider for urban areas.
Other important benefits of green infrastructure include:
- Improves air quality: Adding trees and other plants improves the overall air quality in urban areas. Plants help purify the air by removing pollutants and particulates that have a negative impact on public health. Trees also produce cooler surface air temperatures, which helps decrease the production of smog. Reducing urban heat also decreases the use of fossil fuels to keep homes and businesses cool in the summertime.
- Enhances water quality and increases groundwater supply: Areas with vegetation cover typically have better water quality, as trees trap rainwater and prevent runoff. Water caught by permeable soil and vegetation increases the groundwater supply. More groundwater also leads to less harmful runoff and prevents pollution from entering waterways.
- Protects against flooding: When rainwater is absorbed by soil and plants, it reduces the amount of water funneled into bodies of water. Trees also help capture and slow rainwater that lands on their leaves and branches. Traditional drainage systems, on the other hand, move this water to waterways very quickly, which leads to flooding. When rainwater is slowed down by green infrastructure, there's less risk of rivers and lakes flooding.
- Provides wildlife habitats: Even small parks and green spaces can become the habitat for a wealth of creatures, including insects, reptiles, birds and small mammals. These thriving ecosystems are essential to a sustainable environment.
- Reduces urban heat islands: Green walls and roofs absorb light and prevent it from reflecting off of buildings. This produces cooler temperatures in cities that are notorious for excess urban heat. Adding vegetation to landscape designs also provides cooling shade. The process of evapotranspiration also has a cooling effect, as purified water vapor is released into the atmosphere.
- Combats climate change: Trees and other plants are useful for sequestering excess CO2 from the air to slow the impact of climate change. While other mechanisms exist for carbon sequestration, biosequestration from trees and plants is both effective and cost-efficient. Green transportation and cooler temperatures also reduce CO2 emissions when fewer fossil fuels are burned to drive cars and run air conditioners.
- Lowers energy costs: Green walls can reduce the heat of the area behind them by up to 10 degrees, meaning green infrastructure has a dramatic impact on comfort levels and energy costs. When the urban heat island is lowered, people don't need as much energy to cool their homes and offices, which leads to financial savings. In the summertime, green walls can reduce energy costs by up to 23 percent.
- Improves quality of life: Parks provide an opportunity for recreation and enable social interaction among community members. Green spaces also encourage relaxation and psychological renewal that leads to better health and wellness. Parks can also become the setting for educational classes, community yoga, concerts and festivals. These events can draw more tourism and increase residents' pride in their city or community.
- Increases property value: Homes built near parks often have a higher property value. Green spaces can also be a selling point for a home, as they provide opportunities for biking, walking and other outdoor activities. Families with kids will also appreciate easy access to parks where their children can play sports or watch concerts.
- Adds beauty: Urban green infrastructure brings lush green foliage and colorful blooms into an otherwise gray and bland space. This aesthetic improvement can lift people's moods simply by making an area more pleasing to look at and enjoy.
Incorporating Green Infrastructure Into Your Landscape Architecture
Landscape architects have a unique opportunity to reduce negative environmental impacts by implementing green infrastructure in landscape design. In addition to benefiting the environment, green infrastructure is also important to many consumers. The 2018 Residential Landscape Architecture Trends Survey from the American Society of Landscape Architects (ASLA) highlighted sustainable landscape design elements as some of the most popular landscape design projects and details. Consumers care about sustainability and will be pleased to enjoy landscapes with green infrastructure.
Whether you're designing a backyard or planning an entire neighborhood, you can implement green infrastructure features to make the space healthier, cleaner and more enjoyable. Below are some effective ways to incorporate green infrastructure into landscape design on both a small and large scale.
Small-Scale Green Infrastructure Projects
Several small-scale green infrastructure options exist, including the following:
Rain Gardens and Bioswales
Over 71 percent of the landscape architects surveyed listed rain gardens as one of the most popular landscape design trends for 2018. Rain gardens offer a versatile way to incorporate green infrastructure into any landscape, as they can be designed in any shape or size to fit the space.
These gardens can be filled with rocks, gravel, mulch or any variety of foliage or flowers that work well with a color scheme and design vision. They can be constructed on any unpaved surface and provide a beautiful and simple way to incorporate green infrastructure into residential or commercial landscape design. Bioswales are perfect for larger commercial landscape design. Commonly built along roads or parking lots, bioswales are typically designed to absorb a specific volume of rainwater and can be very effective at preventing flooding.
Green Walls and Roofs
Adding vines and other foliage to walls can be a beautiful way to reduce urban heat and cool a building's interior. Green walls can also be constructed in layered terraces with small plants for a more modern appeal. In addition to reducing energy costs, green walls also make a home or business quieter by trapping outside noise and preventing it from entering the building.
Green walls are a flexible design feature. They can be constructed in large-scale panels or smaller segments. Green roofs are another great option in crowded urban spaces and provide both cooling and rainwater management. Green roofs are covered with grasses or other foliage that effectively absorbs up to 60 percent of rainwater to reduce stormwater runoff and flooding. When paths and seating are incorporated, green roofs can also become an enjoyable space for consumers.
When adding paths or driveways in landscape design, remember that permeable pavement can be a great option for better stormwater management. While traditional pavement or concrete creates runoff, permeable pavement allows water to be absorbed into the earth. Permeable pavement can be incorporated as porous asphalt, pervious concrete or interlocking pavers or tiles. The variety of options makes it easy to integrate this solution into your landscape design. Permeable pavement was also listed by 74 percent of landscape architects as a landscape design project with high consumer demand.
Native plants were ranked number one as the most in-demand landscape design element for 2018. Using native plants in landscape design is also excellent for the environment, as native plants typically require less irrigation or watering than non-native species.
When invasive non-native species are incorporated into landscape design, they can dominate the space and reduce biodiversity, which is essential to creating a resilient ecosystem. Non-native plants also weaken soil and make the environment more susceptible to disease. By using native plants in your landscape design, you can produce a beautiful and healthy landscape that will withstand harsh weather.
Large-Scale Green Infrastructure Projects
The following are some large-scale types of green infrastructure:
Parks and Nature Reserves
When planning a community and plotting development areas, it's essential to include plans for preserving and expanding green spaces in the form of parks and nature reserves. Green spaces improve public health and quality of life as well as producing a healthier environment. Interlocking or connected parks in cities are essential for allowing wildlife to travel through urban spaces. They also provide opportunities for recreation and create more beautiful cities and neighborhoods.
Wetlands are extremely effective at capturing and purifying stormwater and creating cleaner water. They're often added to city design in parks, near existing bodies of water or around the edges of cities. Constructed wetlands are typically small pools or trenches that contain some amount of water at all times.
When incorporating wetlands into landscape design, you can choose a variety of foliage to best suit the climate and the specific environmental goals. Different foliage will be more effective for trapping rainwater or treating wastewater. On top of benefiting the city and its surrounding ecosystems, wetlands can be a beautiful landscape feature that consumers can enjoy.
Greenbelts and city bike trails offer another beautiful way to incorporate green infrastructure in your landscape design or city planning. Green transportation reduces pollution while also improving public health and providing recreation opportunities.
Shade Structures in Sustainable Landscape Design
Incorporating shade structures in your landscape design can also help reduce urban heat and make outdoor spaces more livable. Adding shade over trails and paths makes them more enjoyable on sunny days, and shade structures in parks provide protection from harmful UV rays. At USA SHADE, we care about producing sustainable and high-quality structures that will last.
Our shade structures add to any commercial landscape design and can be customized for any space. Contact us today to learn more about the shade solutions we offer.