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Green Infrastructure | P2

As cities and communities grow, homes and roads are developed and ultimately covering soil with concrete and asphalt. While this creates accessibility for the growing community, water is unable to get into the ground causing problems such as floods, increased erosion and polluted runoff. Green infrastructure can help you manage stormwater more sustainably and use it to divert water for useful purposes such as growing vegetation | Learn More >


What Is Green Infrastructure?

Green Infrastructure (GI) as defined by EPA is a cost-effective, resilient approach to managing wet weather impacts that provides many community benefits. GI treats stormwater at its source while delivering environmental, social and economic benefits | See EPA's Definition >

Here are some simple pollution prevention (P2) practices to use while implementing green infrastructure:

Rainwater Harvesting

Rainwater harvesting systems collect and store rainfall for later use. Collected rainwater can be used as a substitute for traditional irrigation methods and can help save money on water bills.

Downspout Disconnection

Downspout disconnection reroutes rooftop drainage pipes from draining rainwater into the sewer while redirecting it into rain barrels, or reservoirs, permeable areas.


These are areas of vegetated, mulched or xeriscaped channels that provide treatment and retention as storm water moves from place to another. Bioswales slow, infiltrate and filter stormwater flows. Typically these features are linear and are placed along streets and parking lots.

Permeable Pavements

Permeable pavements allow rain and snowmelt to seep through the surface into the ground. These pavements infiltrate, treat and/or store rainwater where it falls. Pavements can be made of pervious concrete, porous asphalt or permeable interlocking pavers.

Green Roofs

Green roofs are covered with vegetation that enable rainfall infiltration, evapotranspiration of stored water and reduce stormwater runoff. Green roofs also help regulate internal building temperatures and reduce the overall heat island effect. These roofs work well in dense urban areas where land values are high and where storm water management costs are likely to be high.

Rain Gardens (Bioretention)

Rain gardens, also known as bioretention or bioinflitration are shallow, vegetated basins that collect, absorb and remove pollution from runoff on rooftops, sidewalks and streets. These gardens are versatile and can be installed in almost any unpaved space. Implementing rain gardens or bioretentions can decrease costs required for construction storm water conveyance systems.

Green Parking

Integrate GI into parking lots. This includes permeable pavements, bioswales in the medians and along the parking perimeter, rainwater harvesting, and downspout disconnections.

Use EPA's Green Infrastructure Wizard >

Case Study

A case study conducted by EPA, the City of Phoenix and several consultants evaluates GI barriers and opportunities for the city of Phoenix. The document looks at local codes and ordinances and offers example language to address GI barriers | Green Infrastructure Barriers and Opportunities in Phoenix, Arizona >

Additional Resources

Listen in to EPA’s Green Infrastructure Webcast Series >

Topics include:

  • Building the Case for Green Infrastructure: Outreach and Education
  • Lessons Learned in Green Infrastructure
  • Greening Vacant Lots
  • Winter Weather O&M for Green Infrastructure
  • Green Infrastructure for Arid Communities
  • Green Infrastructure for Localized Flood Management
  • Green Infrastructure and Smart Growth

Use EPA's National Storm Water Calculator > 

Use EPA's Storm Water Management Model > 

Use the Green Infrastructure Flexible Model >