Green Infrastructure

What is Green Infrastructure?

An interconnected network of green space and other environmental assets that conserves the functions of the natural ecosystem and provides associated benefits to people. (Adapted from the Conservation Fund, Ed McMahon and Mark Benedict)

Definition  “Green Infrastructure Work Group” US

“an interconnected network of waterways, wetlands, woodlands, wildlife habitats, and other natural areas; greenways, parks and other conservation lands; working farms, ranches and forests; and wilderness and other open spaces that support native species, maintain natural ecological processes, sustain air and water resources and contribute to the health and quality of life for America’s communities and people.”

Definition: “The Town and Country Planning Association”, UK

“The sub-regional network of protected sites, nature reserves, green spaces, and greenway linkages”. The linkages include river corridors and flood plains, migration routes and features of the landscape, which are of importance as wildlife corridors.”

Concept Of Green Infrastructures

·         “Green infrastructure” refers to natural and engineered ecological systems that act as living infrastructure, integrating natural vegetation and soils into a community’s infrastructure through a variety of techniques, approaches, technologies, and practices.

·         Green infrastructure is planned and managed primarily for storm water control, but it also provides additional social, economic, and environmental benefits. It can be a useful tool for communities that are looking to protect their natural water resources and storm water management systems from the impacts of development and urbanization.

·         Green infrastructure methods can be implemented practically anywhere soil and vegetation can be worked into a landscape.

Green Infrastructure Hubs and Corridors

The two main physical components of green infrastructure networks are hubs and corridors.

Hubs

•          Hubs are large blocks of unfragmented natural areas that anchor the                                  network.

•              They provide space for native plants and animal communities and an origin                        or destination for wildlife, people, water, nutrients, and energy moving                               through the system.

Corridors

•              Corridors connect these hubs and tie the system together, providing                                    conduits for movement, for plants, animals, water, and nutrients.

•              Corridors have also been shown to mitigate the effects of habitat                                        fragmentation and enhance the overall resiliency of natural systems in the                           face of natural and human disturbances

The Green Infrastructure has its origin (John Olmsted and Frederick Law Olmsted Jr. 1903) in 2 main important concepts which are:

1.      Linking parks and other green space for the benefit of people.

2.      Preserving and linking natural areas to benefit biodiversity and encounter habitat fragmentation.

However, throughout years new concept had been adding. Green Infrastructure today is influenced by 4 main factors :

1.      Linking parks for people;

2.      Linking natural areas to counter fragmentation and preserve biodiversity;

3.      Identifying and protecting interconnected open spaces systems to benefit wildlife and ensure a sustainable future;

4.      Building upon the excitement and appeal of the modern-day greenways movement

       TYPES of Green Infrastructure?

1.      Green Roofs

2.      Rain Gardens

3.      Porous and Pervious Pavements

4.      Vegetated Swales

5.      Pocket wetlands

6.      Planter Boxes

7.      Green Parking

8.      Rain Barrels

9.      Downspout Disconnection

10.  Community Forestry and Trees

     1.      Green Roof

Green roofs are roofs of buildings that are covered with vegetation and soil, either partially or completely. Green roofs are layered systems, with a waterproof membrane, drainage mat, root barrier, growing medium, and vegetation.

     2.      Rain gardens

Rain gardens also called bioretention basins, are planted topographic depressions that are designed to absorb rainwater that drains from impervious areas, such as roofs, parking areas, streets, walkways, and compacted lawn areas.

     3.      Porous and pervious pavements

Porous and pervious pavements, also called permeable pavements, are paving methods that allow rainwater to infiltrate through them into the soil below.

     4.      Vegetated swales

•      Vegetated swales, also known as bioswales, are wide, shallow channels that are covered on the side slopes and bottom by a dense stand of native vegetation. Vegetated swales are designed to promote infiltration, reduce the flow velocity of stormwater runoff, and trap particulate pollutants and silt. They can be either natural or constructed, and are often used around parking lots so that pollution from automobiles that is picked up in stormwater can be treated before entering the watershed.

      5.      Pocket wetlands

•      Pocket wetlands receive, retain, and treat stormwater that has drained from a limited impervious area. Not only do they reduce stormwater runoff, but they also provide for the filtering of pollutants. Additionally, pocket wetlands are aesthetically pleasing and can even serve as a small wildlife habitat. Pocket wetlands do not require as much space as other stormwater treatment, so they can be very helpful in congested urban areas.

     6.      Planter Boxes

•      There are two types of planter boxes: contained planters and infiltration planters. Contained planters are planter boxes that are placed over impervious surfaces. They hold trees, shrubs, and ground cover. Infiltration planters are containers or structures with open bottoms that contain a layer of gravel, soil, and vegetation.

•      They are designed to allow stormwater runoff to temporarily pool on top of the soil and then slowly infiltrate into the ground.

•      Stone, concrete, brick, plastic lumber, or wood can all be used to construct infiltration planters.

   

     7.      Green Parking

Green parking refers to parking lot design that incorporates green infrastructure instead of only considering purely functional requirements. Green parking involves managing stormwater on‐site, providing generous landscaped areas, planting trees, enhancing pedestrian and cycling infrastructure, and reducing the urban heat island effect.

    

     8.      Rain Barrels

•      Rain barrels, also called rainwater tanks, are water containers that are used to collect and store rain water. The rainwater is usually collected from rooftops via rain gutters. Rain barrels help to reduce the amount of untreated stormwater runoff into wastewater systems and surface waters. The water stored in rain barrels can be recycled for many uses, including water gardens, washing cars, agriculture, and home use.

•      They can also simply store stormwater to be released at a future time.

       9.      Downspout Disconnection

•      Downspout disconnection systems redirect stormwater from traditional collection systems to vegetated areas. By doing so, green infrastructure components can manage the runoff and stormwater volume is removed from collection systems. A street bump-out, or curb extension, is an extension of typical curb that creates an open space that is used to temporarily store and filter runoff.Street bump-outs reduce stormwater flow velocity and volume, as well as improve water quality, with vegetation and possibly infiltration.  A street bump-out can be implemented in any street of adequate width. In addition to enhancing street aesthetics and providing stormwater management, street bump-outs provide traffic calming, which improves pedestrian safety.

      10.  Community Forestry and Trees

 Trees and forests are essential elements of a community’s green infrastructure. These include not only public and private forest lands but also community forests: the canopy of trees in our communities’ yards, parks, roadsides and streetscapes, commercial centers, common areas, and public spaces. They provide many environmental and economic benefits to property owners, communities, and watersheds.

          The Benefits Of Green Infrastructure?

Green infrastructure systems benefits us in many ways. The clean water you drink may have been naturally purified by the roots of a forest; the trees in your front yard trap dust and harmful gases from the air you breathe; and the medicine you take comes from unique plants and flowers.  We need to recognize these benefits of nature, or green infrastructure networks, and understand how they affect our health and our economy. (The Nature Conservancy). Green infrastructure delivers vital public health and safety benefits through wildfire suppression, safe drinking and agricultural water, healthy food production, and protection from flood hazards and storm dangers. Furthermore, the implementation of green infrastructure & it’s management can create jobs and opportunities for Federal funding.

The Health Benefits of Green Infrastructure

v  Absorbs air pollution. Reduces urban core temperatures. (USFS)

v  Streams and aquifers filter & clean the water before it is treated.

v  Provides fresh, healthy food at low-costs at an ever-increasing number of farmer’s markets & community gardens.

v  Increases physical activity and correlates to a decreased incidence of doctors visits and depression. Reduces obesity. (President’s Council on Fitness)

v  Maintains opportunities for children to experience and explore nature.

The Social Benefits of Green Infrastructure

v  Reduces stress. Increases quality of life and family enjoyment.

v  Increases interaction in the community. Enhances community character.

v  Safer public spaces as a result of increased activity. (Trust for Public Land)

v  Evidence shows urban trees and green spaces decrease rates of violence and crime in urban areas and other neighborhoods. (USFS)

The Environmental Benefits of Green Infrastructure

v  Protects habitat, carbon storage, aquifer recharge. Preserves views.

v  Reduces risk of wildfire and other ecological impacts. (USFS)

v  Reduces transportation costs and emissions output. Minimizes inversion. (EPA)

v  Federal law requires improvements for stormwater discharge. (EPA)

The Economic Benefits of Green Infrastructure

Ø  Green Infrastructure corresponds strongly to property values.

v  Homes adjacent to parks are worth 22% more. (Donjek Inc, 2009)

v  Nearby recreation areas and parks raise home values 15 - 20%. (ibid)

v  Permanently protecting forests raises property values 19 - 35%. (ibid)

v  Green Infrastructure is attractive to businesses & residents.(RNA)

v  Supports local businesses and tourism. Green Infrastructure sells homes. (ibid)

The Economic Benefits of Green Infrastructure

A Green Infrastructure Network provides Environmental Services.

v  Cities can use Green Infrastructure to reduce public costs for stormwater management, flood control, transportation, and other forms of built infrastructure.

v  Utilizing and enhancing existing Green Infrastructure reduces the need for newly built or increased infrastructure such as water treatment plants, sewer systems, and detention ponds.