Green Infrastructure and Low-Impact Development Technologies
A rain garden designed and constructed by students in Florida.Copyright Ryan Locicero, WARE raingardens.us (author)
Students are introduced to innovative stormwater management strategies that are being used to restore the hydrology and water quality of urbanized areas to pre-development conditions. Collectively called green infrastructure (GI) and low-impact development (LID) technologies, they include green roofs and vegetative walls, bioretention or rain gardens, bioswales, planter boxes, permeable pavement, urban tree canopy, rainwater harvesting, downspout disconnection, green streets and alleys, and green parking. These approaches differ from the traditional centralized stormwater collection system with the idea of handling stormwater at its sources, resulting in many environmental, economic and societal benefits. A PowerPoint® presentation provides photographic examples, and a companion file gives students the opportunity to sketch in their ideas for using the technologies to make improvements to 10 real-world design scenarios.
Green infrastructure and low-impact development are decentralized stormwater management strategies that provide on-site water quantity and water quality treatment. These systems utilize physical, chemical and biological principles to improve the water quality of urban stormwater runoff. Under natural conditions (pre-development), stormwater runoff has unabated access to the soil surface. This stormwater runoff recharges the groundwater supply and provides a certain level of stormwater cleansing, improving the long-term security of drinking water supplies and supporting ecosystem function. Green infrastructure is considered a new technology and significant civil and environmental engineering research is underway. Engineers are taking a look at how nature naturally manages stormwater and nutrients and conducting research to understand how to best design, install and maintain these systems over their anticipated lifespans.
After this lesson, students should be able to:
- Describe the guiding principles of green infrastructure and low-impact development.
- Explain the advantages of green infrastructure and low-impact development technologies compared to traditional stormwater infrastructure.
- Select location-appropriate green infrastructure and low-impact development technologies.