Green Infrastructure is about bringing together natural and built environments and using a cities’ landscape as infrastructure. It is defined as natural vegetation and vegetative technologies that collectively provide society with a broad array of products and services for healthy living; and takes many forms including urban forests, natural areas, green roofs and green walls, parks, gardens, landscaped areas, engineered wetlands, and stormwater ponds. It also encompasses soil volumes and qualities adequate to sustain living green infrastructure and absorb water, as well as technologies like porous paving, cisterns and structural soils.
Green infrastructure provides a multitude of economic, social, environmental, and health benefits – most of which are not recognized in our current legislation and policies. Because it is such a critical element in the sustainable urban planning process, we believe that the design of a city around landscape, rather than around architecture, is more capable of organizing a city and enhancing the urban experience.
At GreenBlue, we envision a future in which the many contributions made by green infrastructure to quality of life are recognized, protected, maintained, and enhanced.
How Urban Trees Relate to Green Infrastructure
The benefits that trees bring to the urban environment are numerous, however the maximum environmental and social benefits of a tree are not realized until the tree is fully established. Unfortunately, most urban trees planted in our cities do not reach full maturity due to improper planting techniques.
Think of a tree in a woodland setting… It has near perfect conditions while a city tree endures a harsh paved surround and all the other elements of the urban climate. Below ground, a hostile environment of compacted soils leads to a lack of quality root volume and competition for space with multiple utilities. The fact that trees can improve the quality of life for city residents and make a positive contribution to large-scale infrastructure requirements is making the establishment of healthy urban trees a central component in urban planning strategies. But, the right guidelines must be followed to successfully integrate trees in built up areas, including the use of tree literate design.
How Stormwater Management Relates to Green Infrastructure
Low Impact Development (LID) is a response to drainage problems arising from increasing levels of urbanization and the density of new building development, both of which have exacerbated the limitations of conventional surface-water drainage measures.
While traditional drainage systems for surface water runoff have been designed to convey rainwater from where it has fallen to either a soak-away or a watercourse as rapidly as possible. This method increases the risks of flooding, environmental damage, and urban diffuse pollution – as runoff water usually carries contaminants including oils, heavy metals, pesticides, fertilizers, chemicals, and other organic matter.
Authorities are increasingly mandating that developers adopt a sustainable approach to drainage. The implementation of sustainable drainage systems – demonstrated in outline as well as in detailed planning applications and design submissions – is now demanded by authorities, from early site evaluations through to the completion of EIAs (Environmental Impact Assessments). Regulations for new buildings have also been modified to introduce LID protocols, establishing it as part of normal best practice.
In short, we need green infrastructure to keep our communities sustainable. Using purpose designed LID systems, like the ArborFlow tree-pit system that markedly reduces the velocity and flow rate of surface water runoff in urban areas, is a perfect example of using green infrastructure for stormwater management.