“Green infrastructure” is a term used to describe building, design and water management practices that mimic the natural, pre-development water cycle of a developed site. In North America green infrastructure development practices are commonly referred to as “low impact development”.
Every road or building that is built changes the hydrological features of a site. This means that significantly less water is absorbed and filtered by soil and plants and held on a site. Instead traditional grey water systems carry pollutants from roads and rooftops to stormwater systems. In heavy rains this can cause waterway pollution, combined sewage overflows, erosion, and a number of other issues downstream. More and more municipalities are taxing and regulating this runoff because of the burden it puts on stormwater systems and the environmental issues it creates.
Green infrastructure lessens these negative impacts by more closely mimicking the natural, pre-development water cycle. Not only does green infrastructure provide benefits in the water cycle by storing water locally, it improves the energy efficiency of buildings, and provide the social benefits of green space.