Green Infrastructure. Green-roofed house from Pixabay.

Green Stormwater Infrastructure: The Basics

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Updated: August 27, 2017 3:05 pm

Updated: August 29, 2017 6:11 am

Green Infrastructure: What is it?

Green Infrastructure is a method of using nature, through the addition of plants and trees and permeable surfaces, to manage stormwater runoff, reduce pollution, and reduce erosion. You’ve probably seen it in action without realizing what it is, and you will see more of it as communities continue to adopt the policy. You can make simple changes right at home to join the movement and help your local community.

The EPA defines it like this: 

Green infrastructure is a cost-effective, resilient approach to managing wet weather impacts that provides many community benefits. While single-purpose gray stormwater infrastructure—conventional piped drainage and water treatment systems—is designed to move urban stormwater away from the built environment, green infrastructure reduces and treats stormwater at its source while delivering environmental, social, and economic benefits.

Stormwater runoff is a major cause of water pollution in urban areas. When rain falls on our roofs, streets, and parking lots in cities and their suburbs, the water cannot soak into the ground as it should. Stormwater drains through gutters, storm sewers, and other engineered collection systems and is discharged into nearby water bodies.

The stormwater runoff carries trash, bacteria, heavy metals, and other pollutants from the urban landscape. Higher flows resulting from heavy rains also can cause erosion and flooding in urban streams, damaging habitat, property, and infrastructure.

What can you do at home?

There are a number of things that you can do right now at your own home.

Rainwater Harvesting using rain barrels

Green Infrastructure: Rain Barrels. Photo from Creative Commons.
Green Infrastructure: Rain Barrels

Rainwater harvesting systems are designed to capture and store runoff from your roof. When designed appropriately, they not only slow and reduce rainwater runoff but can prevent the spread of polluted stormwater.  Rain barrels can include filter systems containing sand, charcoal and limestone to clean the water before it is released back into your landscape.

You benefit by obtaining a free source of irrigation water and your community benefits from stormwater reduction and the removal of pollution from stormwater runoff.

The right to use rain barrels varies from community to community, so check your local ordinances before purchasing. The water stored and filtered is not intended for human consumption, but can be used for irrigation.

Rain Gardens

Current Water. Green Infrastructure.
Raingarden. Photo from the EPA.

Rain gardens are often planted at the bottom of a slope to capture rain runoff from rooftops, sidewalks, and streets.  Plant the garden with trees, shrubs or flowers that can withstand both droughts and occasional floods. These are also known as bioretention, or bioinfiltration, cells.

You benefit by adding a beautiful landscape feature and reduce erosion in your yard. Your community benefits from less stormwater volume, lower flooding risks,  and less pollution.

Downspout Disconnection

Current Water. Green Infrastructure.
Downspout disconnection into permeable bed. Photo from the EPA.

This is a simple method that involves disconnecting your downspouts and preventing rain water from flowing into the storm sewer system. In addition to directing rainwater into rain barrels or cisterns, it can be sent into permeable areas (such as the pebble field shown here or into a rain garden).

You benefit from capturing free water for irrigation. Your community benefits from the reduction of stormwater volume which can overwhelm combined sewer systems and cause flooding.


Plant a tree 

Current Water. Green Infrastructure.
Plant a tree

Trees reduce the volume and speed of stormwater when rainwater is interrupted by branches and leaves. Adding compost or mulch at the base of the tree will help retain moisture and replace nutrients. Stands of trees also help prevent the transport of sediment and chemicals into streams.

It addition to providing oxygen and shade, trees also filter out contaminants and help to recharge the ground water supply.

You benefit from increased property values and a beautiful landscape feature. Your community benefits from reduction of stormwater volume and speed, carbon dioxide removal, additional oxygen generation, and the addition of a natural habitat for birds and other creatures.

Before you begin

Prior to starting a green infrastructure project, check your local ordinances to see what is allowed and whether permits are required.  Many communities offer “tool kits” online to help you in your planning process.

By: Jennifer Croft

Upcoming: How Seattle is implementing Green Infrastructure Projects. Also, other types of Green Infrastructure Projects protecting Urban, Marine, and Agricultural Landscapes.

For more details on Green Infrastructure ideas from the EPA, click here

For more information on the Salmon-Safe program (Green Infrastructure used to protect Pacific NW salmon habitats) click here

For more information on the benefits of trees from the Arbor Day Foundation, click here

For a Green Infrastructure tool kit from GrowNYC, click here

For a Green Infrastructure guide from Omaha Stormwater, click here

Featured Green Infrastructure illustration from Pixabay