Gray and Green Infrastructure for Increased Urban Resiliency

2 mins read
JAN 23 Gray and Green Infrastructure for Increased Urban Resiliency 1

One of the major concerns of cities around the world is the environmental degradation of urban water bodies. Efficiently managing these waterbodies and stormwater is important to safeguard the environment. Today, the climate as well as the world is changing rapidly which makes it hard to manage and store stormwater. It sure is hard but not impossible and you can use gray and green infrastructure to solve this issue. In this article, you will learn about the ways to utilize gray and green infrastructure for increased urban resiliency, integrating green and gray, etc.

What is Grey Infrastructure?

For stormwater management, Grey infrastructure refers to a network of water purification and retention infrastructure. It includes things like retention ponds, culverts, pipes, swales, and ditches. The purpose of this infrastructure is to slow down the flow of stormwater during rain events. It prevents flooding and also reduces the number of pollutants entering waterways.

What is Green Infrastructure?

In Urban areas, the runoff from stormwater is a major reason for water pollution. This water carries pollutants like heavy metals, bacteria, trash, etc. through storm sewers into local waterways. Earlier communities dependent on gray infrastructures, such as systems of tunnels, pipes, and gutters to move stormwater away from where they lived but now a lot of communities are shifting more towards green infrastructure.

Green Infrastructure absorbs as well as filters stormwater where it falls. It makes strategic use of networks of working landscapes, natural lands, and other open spaces to conserve ecosystem functions and values. It also provides associated benefits to human populations.

Integrating Green and Gray Infrastructure

Earlier, the world relied on traditional infrastructure systems for the safe and smooth functioning of societies. However, now the world is facing rapid climate change and environmental threats and this approach are not efficient alone. It’s important to use gray and green infrastructure for increased urban resiliency. Natural systems soils, forests, and floodplains can contribute to a reliable and clean water supply. They also protect against drought and floods. Integrating green and gray infrastructures such as levees, pipes, dams, reservoirs, and treatment systems to boost resilience, system performance, lower costs and better protect communities. To use green infrastructure appropriately in mainstream infrastructure programs, the green infrastructure must be carefully designed and evaluated as gray projects. After this, let’s learn about grey infrastructure vs green infrastructure.

Also Read: Superstorm Sandy – A Climate Change Reality Check – Energy Theory

Grey infrastructure vs Green Infrastructure

The concept of grey infrastructure vs green infrastructure comes down to the point of whether the infrastructure uses its natural process to design solutions or to control nature. In the case of natural systems, the water does not travel over miles and miles over land without soaking into the ground, except in a river. Whereas, with gray infrastructure, stormwater may travel a long way over impermeable surfaces before it reaches a river, lake, or sea. By this time the water picks up toxins, nasty critters, and pollutants.

Gray infrastructure often doesn’t give water anywhere natural to go and thus this water has no choice but to head to destinations such as sewers. These destinations mostly can’t handle the volume of this water and this further results in overflow that poisons the environment. On the contrary, green infrastructure consists of elements that help nature do its job. It allows water to soak into the ground which filters the pollutants naturally. This retains water just as nature does and keeps it in place when it falls rather than funneling it. Green infrastructure is cheaper and better than gray infrastructure. However, keep in mind that society needs to use both gray and green infrastructure for increased urban resiliency.

Horacio Terraza is the coordinator of the Inter-American Development Bank’s Emerging and Sustainable Cities Initiative (ESCI), Infrastructure Management and Environment Sector. He is also a Lead Water and Sanitation Specialist with the Water and Sanitation Division. Trained as a mechanical engineer at the University of La Plata in Argentina, he has extensive experience developing complex projects related to urban and industrial pollution, working for 20 years in the private sector and multinational development organizations. Horacio also holds a Masters in International Economics and International Relations from SAIS at the University of Johns Hopkins.

Leave a Reply

Your email address will not be published.