Green Infrastructure
Green Infrastructure is officially defined in the Water Infrastructure Improvement Act(2019) as “the range of measures that use plant or soil systems, permeable pavement or other permeable surfaces or substrates to evapotranspirate stormwater and flows to sewer systems”.
This is in contrast to gray infrastructure, which is just normal roads, buildings, parking lots, etc.
Types of Green Infrastructure
- Green Roofs: filters rainwater and enables evapotranspiration, effective in cities with tall buildings
- Rain Gardens: small sunken areas with plants, absorbs rainwater, reducing runoff
- Bioswales: like rain gardens, but found in long strips by the side of roads
- Permeable Pavement: pavement with pores that allows water to go through, can help with runoff and flooding in urban spaces
- Urban tree canopy: trees absorb and help evaporate water, shade helps keep temperatures cool on hot days
- Downspout Disconnection: rerouting roof drainage pipes from the sewer to a storage barrel or to the ground, helps reduce runoff
- Land conservation: protecting natural spaces and leaving some as they were when building cities and suburbs
Benefits of Green Infrastructure
- Reducing runoff: Green Infrastructure can filter and absorb runoff water which could have causes negative effects such as eutrophication
- The urban heat island effect is when materials such as concrete and asphalt tend to absorb lots of heat, raising temperatures in cities compared to the countryside. This can increase risk of heat stroke, and also makes cities unpleasant to live in. Having green spaces and trees can create shade and help lower temperatures
- Removing air pollution: Trees can filter particulate matter from the air, and make it cleaner to breathe
- Aesthetics and Recreation: trees are nice to look at, and people can go hiking/take a walk in parks and green spaces