Green space in urban environments provides many advantages: formal and informal sport and recreation, preservation of natural environments and even urban storm water management. As the world’s cities continue to grow, continuing to value green space in cities is vital. Thus green space must be a key consideration in urban planning if the health of a city and its people are both considered important.
As our urban locations grow water shortages will have implications on green spaces within these urban landscapes. Without water to maintain green space, and with temperatures already on the rise, there will be greater potential for extreme heat events. Grass and trees provide beneficial ecological services, such as evapotranspiration, shading, and cooling of the surrounding environment. Decreasing levels of green space in urban areas exacerbates the impact of existing GHG emissions by trapping heat (the urban heat island effect) and promoting the creation of more harmful secondary pollutants.
Diminished green space is also tied to health impacts related to heat stroke or respiratory disease. It also exacerbates activity-related illnesses such as obesity and heart disease, and can be a disadvantage to individuals suffering from mental health issues, such as attention deficit hyperactivity disorder. Additional drawbacks include the loss of social capital from green spaces used as meeting points, decreased activity, and potential exacerbation of chronic illness in elderly populations.
Although some urban settings irrigate large green spaces and golf courses with recycled water, many of them do not currently have the infrastructure in place to use recycled water for irrigation. In the past there has been challenges due to the cost of installation of supplemental distribution systems for recycled water. As of late there have been advances in technologies that can allow for urban greenspaces to retrofit existing wastewater collection systems to be used in reuse applications. Innovations such as transportable and packaged wastewater treatment plants are allowing for broader use of water reuse across the globe.
If the current drought situations around the world persists, mandatory irrigation restrictions could be implemented for urban parks. Similar mandates were put in place in many parts of Australia in the early 21st century in response to its severe drought that resulted in the absence of green spaces and led to negative health implications.
The reality that we are facing is that the only feasible solution to overcome the persisting drought situation around the world lies in using wastewater as a resource rather than a waste product, at a minimum, to irrigate and maintain green spaces in urban areas, thus reducing the severity of extreme heat events. Installations of supplemental distribution systems are required for recycled water to irrigate green spaces.