Ever wonder what happens to all the stormwater that falls on our yards, homes, schools, businesses and cities? What pollutants does it pick up as it washes away? And what creative ways can we manage all that water to minimize the load on municipal systems and the environment?
Find out by wading into the technology and engineering in the two Serious Sciences videos here. When you’re finished learning about urban grey infrastructure, explore the "Supa-Green Infrastructure" video to the right to see very cool ideas for creating green infrastructures in your business or home. The technology and innovation of this green science are sure to “grow” on you.
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When it rains, most people are more concerned about finding their umbrellas or raincoats than what happens to all the water draining from their homes, driveways and yards. Yet stormwater runoff, and the pollutants it often carries into our waterways, remains a significant threat to water quality. Likewise, few people consider where all the wastewater goes when you brush your teeth, take a shower, or flush the toilet. It just magically disappears, right? Sorry, it may be out of sight, but if you care about the environment, it shouldn’t be out of mind.
In many cities such as Milwaukee, the largest city in Wisconsin, they use grey infrastructure to help manage their stormwater and wastewater. Milwaukee Metropolitan Sewerage District has the huge task of handling all that sewage and stormwater and to prevent pollution from the discharge of treated water into nearby Lake Michigan.
So what is this grey infrastructure anyway? It’s easy enough to see their massive sewage treatment facilities that handle the sewage generated throughout the city and 28 municipalities that are part of the District. But where does all that stormwater go when it washes off the streets and buildings and runs down the storm drains?
Watch the video below to get an underground look at how their Deep Tunnel system works 24-7 to prevent untreated sewage from being discharged into Lake Michigan.
Another method of managing stormwater runoff is with green infrastructure. This is where individual homes and businesses employ a variety of methods and technologies to prevent runoff from their properties. Watch the video above and to the right to see a Supa-Green Infrastructure in action.
To really dig deeper into the environmental implications of both grey and green infrastructures in your home or city:
Explore the extended learning section below by clicking on the “Learn More” tab below to discover more about grey and green infrastructures.
Or better yet, ask your teacher to download the lessons below so your entire classroom can share in peer-driven learning.
Also, find out more about what you can do to keep your local waters healthy and clean by checking out the website of our educational partner, Wisconsin Land+Water.
Alright, so what is grey and green infrastructure? And how can these help manage water pollution? The answer lies in the science, technology, engineering, and math used in their development. Both offer potential solutions to water quality concerns while each has its own advantages and disadvantages to consider.
Grey infrastructure is far more common than green. Engineers also refer to this form of infrastructure as “traditional” infrastructure because it is the norm for servicing most cities across the country. All of those pipes, drains, culverts, and tunnels beneath your feet collectively make up grey infrastructure. These structures gather storm water into central locations underground and cause it to flow to a treatment facility or straight to a body of water.
Many city engineers have a goal of centralizing falling water as quickly as possible and moving it away from human development. Grey infrastructure can accomplish this goal very well. This method of dealing with stormwater effectively prevents water from building up on roads, in parking lots, or around subdivisions. Furthermore, the pipes and water storage basins make the process of treating wastewater easier because they concentrate a good percentage of falling water into one spot. But the challenge is that nature doesn’t always behave as we humans want it to.
When water naturally falls from the sky, the exposed soil on the ground absorbs some of it. Rooftops, pavement and concrete however prevent rain from reaching the soil. If parts of the grey infrastructure get blocked by debris that gets washed into drains, a lot of water could flood into nearby rivers or lakes. During heavy rain events, this type of flooding becomes a serious concern.
Grey infrastructure also prevents evaporation from taking place as much as it normally would on exposed soil. Evaporation naturally takes up as much as half of the water that falls on exposed soils during a given rain event. But grey infrastructure moves water underground before much evaporation can occur. This means that up to two times as much water enters wastewater treatment facilities or bodies of water when grey infrastructure captures urban runoff.
Plus, when we build new roads, buildings, and homes above the ground, cities need to also build underground grey infrastructure to handle all the newly generated sewage and stormwater runoff. And that costs cities and taxpayers tons of money.
So what’s a solution to help minimize the impact and load on grey infrastructures? Tas-dah! That’s where green infrastructures enter the scene. Green infrastructure solves many of the problems mentioned above while providing additional benefits to our communities and the environment. Here’s the deal.
Green infrastructure are individual stormwater management techniques that help minimize the amount of water washing into the grey infrastructure. Basically, it recreates the various roles nature performs in taking care of precipitation in an urban environment. Green infrastructure takes many different forms, but all of them have a few things in common.
Most green infrastructure projects hold or capture excess water when it falls. For example, rooftop gardens capture water in the soil that plants then use to grow. Rain barrels connected to gutters on roofs collect water that can be used later for watering plants or for washing a car. Finally, hard pavement that is also permeable, meaning that water can pass or “permeate” through it, ensures that water stays on the areas where it falls rather than washing away as runoff into storm drains.
It kinda makes you wonder. Why don’t we see more green infrastructures in every city if they’re so great? Cities typically have a “one-size-fits-all” way of creating their grey infrastructure. This makes it easier to monitor, fix, and pay for tunnels, pipes, or collection basins. Green infrastructure on the other hand often gets built on a single site-specific basis. One building might create a rooftop garden while one home might install a rain barrel. So in the end, green infrastructures make up a variety of techniques and designs that when cumulatively put together, can make a significant impact in managing runoff.
One of the bigger obstacles to creating more green infrastructures is the cost. Businesses and buildings often have to pay for their own projects, even though these might benefit the city and environment more than the business. Cost is also a challenge for many homeowners, especially if they can’t see the environmental return on their investment. However, supporters of green infrastructure cite the many long-term economic benefits to cities and work to put more green infrastructure projects into places on a citywide basis. They claim that these projects create jobs, are far easier to maintain, save on energy costs, and lower healthcare costs by cleaning city water and air.
What do you think? Maybe you’re inspired to start your own green infrastructure project at your home or school. Maybe you would like to learn more about grey infrastructure and figure out a way to make it better in your town. Watch the videos here and write down some ideas. Then, go out and make a difference.
• Even one inch of rain in a city like Milwaukee can dump 7 BILLION gallons of stormwater that needs to be managed.
• Milwaukee's Deep Tunnel has captured and cleaned 98.3% of all the water and wastewater that's entered the regional sewer system since operating began in 1994.
• If you own a house, you own part of the sanitary sewer system that helps protect public health. The section you own is called a lateral and it connects to the sewer system owned by your city or village.
• Stormwater runoff carries trash, bacteria, heavy metals, and other pollutants from the urban landscape that can end up in rivers and lakes..
When it rains, most people are more concerned about finding their umbrellas or raincoats than what happens to all the water draining from their homes, driveways and yards. Yet stormwater runoff, and the pollutants it often carries into our waterways, remains a significant threat to water quality. Likewise, few people consider where all the wastewater goes when you brush your teeth, take a shower, or flush the toilet. It just magically disappears, right? Sorry, it may be out of sight, but if you care about the environment, it shouldn’t be out of mind.
So what is this grey infrastructure anyway? It’s easy enough to see their massive sewage treatment facilities that handle the sewage generated throughout the city and 28 municipalities that are part of the District. But where does all that stormwater go when it washes off the streets and buildings and runs down the storm drains?
Another method of managing stormwater runoff is with green infrastructure. This is where individual homes and businesses employ a variety of methods and technologies to prevent runoff from their properties. Watch the video above and to the right to see a Supa-Green Infrastructure in action.
Urban Stormwater Management
