What Is Green Stormwater Infrastructure? 11 Things (2024) You Must Know

Rain is hard to ignore.

While it’s falling down, people stay indoors, traffic is slower, and sometimes streets flood.

When the rain stops, we forget about it, like it never happened.

Oh, but it did happen!

All that rainwater that slid across roofs, streets, and sidewalks, picking up debris and pollutants, flows into the storm sewers and out into natural bodies of water.

The result of toxic stormwater isn’t pretty, but what can we do about it?

Well, that’s where green stormwater infrastructure comes into play!

What is green stormwater infrastructure, you ask?

It refers to sustainable urban planning that helps prevent harmful stormwater from causing environmental and economic issues.

Let’s take a closer look at ten things you need to know about the concept!

1. What is Green Stormwater Infrastructure?

Green stormwater infrastructure refers to various urban planning concepts that use nature-based ideas to solve issues caused by stormwater runoff.

Cities and towns are mostly designed with materials and sewage systems that do little to slow down water flow or prevent polluted stormwater from getting into the environment.

A few examples of this kind of infrastructure are green roofs, rain gardens, and bioswales (see sections below for more information on types of green infrastructure).

Think about how dirty the roads are.

Each time it rains, the water picks up all sorts of dirty debris and toxins that go right into the sewer.

Green stormwater infrastructure can prevent a significant amount of rainwater from coming into contact with city filth and naturally filter out pollutants picked up along the way, keeping the environment nice and clean.

2. What is Gray Infrastructure?

Before we continue with green stormwater infrastructure, let’s make sure we understand what gray stormwater infrastructure is.

This type of infrastructure refers to storm drains, dams, ditches, gutters, pipes, seawalls, and culverts–systems that don’t reduce the flow of stormwater or naturally filter out toxins.

Additionally, because it’s built with materials that retain more heat than vegetation, such as asphalt and concrete, gray infrastructure can result in the heat island effect–a phenomenon where urban areas have higher temperatures than natural areas.

Some green infrastructure systems like permeable pavement (see in further sections for more information) use similar building materials as gray infrastructure, but they’re used in a way that solves problems instead of creating them.

3. What Is the Environmental Impact of Stormwater?

Stormwater helps to refill our water reserves, but it arguably does more harm than good without proper water management.

Here are the most common problems associated with stormwater:

bulletAlgae overgrowth

As rainwater runs across urban areas, it picks up nutrients from fertilizer and pet waste.

When the water finally settles, usually in a body of water, it results in an overgrowth of algae, which can be harmful to humans and animals; it can also decrease oxygen levels, harming aquatic life.

bulletPollutants, bacteria, and pathogens entering the sewer system

The ground of cities and towns is full of nasty things like human and pet waste, oils, chemicals, and pathogens–you name it, you can find out somewhere on the street.

Well, when it rains, all of those things run off into natural water sources and water reserves and affect water quality.

bulletTrash entering the sewer system

Stormwater is responsible for picking up a lot of trash and polluting wildlife.

It’s the reason turtles end up with straws up their nostrils and why fish are getting stuck in plastic wrapping.

bulletSediment entering aquatic ecosystems

Particles of sediment from streets, buildings, and other gray infrastructure also get picked up by stormwater, and they can prevent aquatic plants from growing, harming the overall ecosystem.

4. What Are the Common Types of Green Stormwater Infrastructure?

Let’s answer the question what is green stormwater infrastructure by looking at the specific types of systems it’s referring to.

You’ll notice that none of the concepts are overly complicated, and most individuals can take easy steps to do their part and help the cause!

bulletRain Gardens

Rain gardens are simply gardens in a small depression that collect stormwater, cause it to be absorbed into the soil, and minimize the amount that goes into the sewers.

The best plants to use are native to the area and can survive waterlogging.

The stormwater should be channeled from the house or building and directed to the rain garden.


Bioswales are strips of vegetation with a slight dip in the middle that go alongside curbs–like nature-based gutters.

The process slows down stormwater and filters out toxins.

Bioswales usually consist of grasses, mulch, shrubs, trees, and perennials.

bulletGreen and Blue Roofs

A green roof is a roof that has vegetation on top of it.

It can help reduce the amount of rainwater that flows onto the street and also fight against the heat island effect.

A blue roof is a roof that can temporarily or permanently store stormwater and slowly release it, reducing the water flow on the streets.

Blue roofs need to be carefully built and monitored because if damage occurs, it could result in a dangerous flow of water.

bulletPermeable Pavement

Stormwater slides across the pavement like butter in a pan.

Permeable pavement has slight gaps in it so that rainwater will fall into the soil and be absorbed.

Think of a pathway paved with bricks that are slightly spaced out–that is permeable pavement.

bulletPlanter Boxes

Planter boxes are very similar to rain gardens; however, instead of depending on a small depression to hold in the stormwater, plant boxes use sidings to keep it in.

These are commonly found in cities to collect stormwater and give the area a pleasing look.

bulletRainwater Collection

Collecting rainwater prevents it from flowing into the streets and sewers.

People can install barrels or other storage vessels and use the water for drinking or watering plants in the future.

bulletDownspout Disconnection

The downspouts on homes and buildings typically direct stormwater into the sewer systems.

Redirecting downspouts to fall into rain gardens, cisterns, or permeable pavement, is a great way to reduce the flow of water and prevent toxins from getting into natural bodies of water.

5. What Are the Advantages of Green Stormwater Infrastructure?

Green stormwater infrastructure may seem like one of those ideas that sounds good but, in reality, falls short.

Well, that’s not the case here.

Being mindful of what happens to stormwater keeps the environment clean, makes the roads safer, minimizes the heat island effect, and benefits the economy.

Let’s check out all the great benefits.

  1. Decreases the amount of stormwater entering sewer systems.
  2. Conserves more water by reducing the need for irrigation and collecting rainfall.
  3. Keeps local vegetation and wildlife healthy.
  4. Increases shade and nesting areas.
  5. Enhances the aesthetics of cities and towns.
  6. Minimizes the heat island effect.
  7. Prevents dangerous road floodings.
  8. Exposes children to eco-friendly systems.
  9. Cuts the cost of building non-green drainage infrastructure.
  10. Decreases the need to treat water.
  11. Helps homeowners cut back on water bills.
  12. Decreases weather-related damage.
  13. Decreases energy use.

bulletEnvironmental Benefits

Green stormwater infrastructure is a wonderful tool to keep our environments clean.

In areas that receive frequent or even semi-frequent rainfall, the quality of life for plants and wildlife takes serious hits.

Keeping local ecosystems healthy directly impacts our lives by slowing down climate change and preserving natural resources–who doesn’t want that?

bulletCommunity Benefits

Rainfall can cause a lot of issues in the community, like flooding, which increases the amount of traffic and increases the chances for accidents to occur.

Implementing green infrastructure reduces those mishaps, creating a safer place to live.

Additionally, the heat island effect will be minimized, decreasing the rate of heat-related health issues and decreasing the amount of energy a city uses to keep buildings and homes cool.

bulletEconomic Benefits

When stormwater pollutes bodies of water, causes flooding, and puts wear and tear on buildings, it takes money to get those things under control.

Using green infrastructure is a great way for cities to save money on clean-up and damage fees and for individuals to save money on their electric and water bills, which is a plus for the overall economy.

6. What Are the Disadvantages of Green Stormwater Infrastructure?

Everything has a pro and a con, right?

Well, that may be true for green stormwater infrastructure, but the pros far outweigh the cons.

Here are the main disadvantages.

  1. Start-up cost
  2. Codes and licensing
  3. Maintenance

Time and money are the big things working against green stormwater infrastructure.

In order to successfully build these systems, communities have to scrounge up money and completely rethink the current systems in place.

Initially, municipalities will have to get the necessary codes and licensing, which is never a quick process as inspectors have to survey where new systems will be put into place, and lawyers have to make sure all the paperwork is in order.

Maintenance is another factor you could say is working against green stormwater infrastructure.

Since these systems use more vegetation than concrete and asphalt, they’re, in theory, not quite as durable.

Municipalities will have to hire workers to frequently monitor the systems.

With all that being said, a little time, money and effort seem insignificant compared to the potential benefits these new systems could bring.

Hopefully, as more and more cities take the leap of faith into green infrastructure, it will provide a blueprint for others to replicate, easing the initial growing pains.

7. How Durable Are Green Roofs?

One of the most common green stormwater infrastructure systems that you may have already seen is green roofing.

The process of installing a green roof is fairly straightforward for buildings with a flat top.

In addition to stormwater issues, they’re a great solution for preventing cities from being unnaturally hot.

But how durable are they? And how long do they last?

Green roofs are surprisingly resilient.

They are expected to last for more than forty years, although lifespans depend on the quality of maintenance.

Since these roofs also insulate buildings, keeping them cool, they can prolong air conditioners’ lives and prevent structures’ wood from expanding.

They’re the gift that keeps on giving!

8. What Cities in the United States Are Implementing Green Stormwater Infrastructure?

Implementing green stormwater infrastructure is still a new concept, but more and more cities are catching on.

Currently, some of the biggest cities in the nation are declaring their efforts to get rid of gray stormwater infrastructure.

These cities include Los Angeles, New York City, Philadelphia, Portland, Seattle, Cincinnati, Milwaukee, and Washington, D.C.

Evolving into green stormwater management could be huge for these locations.

For example, a study found that stormwater causes Los Angeles to pay up to $35 million per year in health costs–thirty-five million dollars per year.

Even if it costs the city $200 million to upgrade its stormwater management systems, it would only take six years to break even on the investment. After that, it’s all green savings!

Some cities have announced ambitious plans to bring in green stormwater infrastructure. One of those cities in Philadelphia, so let’s take a closer look and see what it’s doing.

9. What is the Philadelphia Green City Clear Waters Program?

In 2011, Philadelphia decided to take action against water pollution and started the Green City, Clear Waters Program–a 25-year plan.

The goal is to greatly reduce the billions of gallons of polluted sewer water that flows into the Delaware and Schuylkill Rivers–primary drinking sources.

Philadelphia’s old sewage system is 200 years old and frequently floods, resulting in sewage and polluted rainwater getting into the rivers.

Since the program started, the city has put into place over 2,800 green stormwater infrastructure systems, which prevent 2.7 billion gallons of polluted water from entering the two rivers.

Those are serious results!

Part of the city’s success is thanks to community outreach and incentive programs that award businesses with grants and credits to install sustainable stormwater management.

Philadelphia is the perfect example of what can be achieved when a city refocuses its attention on beneficial, long-term programs.

10. What is the Singapore Green Infrastructure Plan?

As we’ve been answering the question what is green stormwater infrastructure, there’s one destination we’ve left out that is making great strides in combating water pollution: Singapore.

Since the early 2000s, Singapore has been dedicated to being the leader of the green infrastructure movement.

About two-thirds of all the city’s surfaces are designed with sustainable water management systems to safely channel stormwater into reservoirs.

The green systems generate around 35% of Singapore’s water supply–a huge feat since the country doesn’t have enough water resources to meet increasing demands (it currently imports water from Malaysia).

Singapore will undoubtedly be a place that cities in the United States draw on for inspiration as more attention is put on managing stormwater sustainably.

Final Thoughts

As the years pass, it’s becoming clearer and clearer that the future has to be green.

Green stormwater infrastructure will be hugely beneficial for cities, people, flora, and fauna by preventing polluted rainwater from entering environments.

We’ve already seen in Philadelphia and Singapore how effective these systems can be and how little time it takes to see results.

Don’t forget that we are all capable of making small changes by implementing these systems in our own homes.

So, get outside and get your home ready for the next rainstorm!

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Erika Gokce Capital

Disclaimer: we are not lawyers, accountants, or financial advisors and the information in this article is for informational purposes only. This article is based on our research and experience and we do our best to keep it accurate and up-to-date, but it may contain errors. Please be sure to consult a legal or financial professional before making any investment decisions.


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