Green Infrastructure

Essential Question
How can inclusion of green space in urban areas decrease nonpoint pollution? When/where is which solution appropriate?

Objectives

 * Explain how different solutions reduce energy usage and pollution.
 * Employ knowledge of pros and cons of different solutions to pick one that is appropriate for their city
 * Explain how green infrastructure models a natural environment
 * Predict how different materials will filter runoff and model a natural environment.

Introduction & Student Background
In many urban areas (cities, towns) there is not enough plant life to address various environmental problems. Some of these include erosion (when soil and rocks are swept away by natural processes, which could damage the foundation of buildings), heat island effect/heat stress (Raised temperatures a health risk, especially for vulnerable groups (e.g. elderly, very young). Air pollutants may become trapped, increasing their concentration and the length of people’s exposure to them) and water pollution (in areas with high rainfall, pollutants on the street enter local bodies of water via storm drains).

In this activity, students will learn about different tactics to address various urban environmental issues and apply appropriate tactics to their own community. Some questions to keep in mind -- how narrow are most of the streets in your city? Which one of these issues do you notice the most about your area (too little/too much water)? Do you know what the local natural environment is like?

Vocabulary
bioswales - vegetated, mulched, or xeriscaped channels that provide treatment and retention as they move stormwater from one place to another. They are best along streets and parking lots.

rain gardens - Rain gardens are shallow, vegetated basins that collect and absorb runoff from rooftops, sidewalks, and streets. Rain gardens mimic natural hydrology by infiltrating and evapotranspiring runoff.

planter boxes - Planter boxes are urban rain gardens with vertical walls and open or closed bottoms that collect and absorb runoff from sidewalks, parking lots, and streets.

rainwater harvesting - Rainwater harvesting systems collect and store rainfall for later use. When designed appropriately, rainwater harvesting systems slow and reduce runoff and provide a source of water.

downspout disconnection -  the rerouting of rooftop drainage pipes to drain rainwater to rain barrels, cisterns, or permeable areas instead of the storm sewer. Downspout disconnection stores stormwater and/or allows stormwater to infiltrate into the soil.

Green Roofs: Green roofs are covered with growing media and vegetation that enable rainfall infiltration and evapotranspiration of stored water. Green roofs are particularly cost effective in dense urban areas where land values are high and on large industrial or office buildings where stormwater management costs may be high.

Permeable Pavements: paved surfaces that infiltrate, treat, and/or store rainwater where it falls. Permeable pavements may be constructed from pervious concrete, porous asphalt, permeable interlocking pavers, and several other materials.

Materials

 * Map of urban area (town or city) including: target storm drains, bus routes, major public buildings/cities, and rivers/bodies of water

PREP

 * 1) Set up the map: print out copies of the map or a large laminated version that students can write on
 * 2) Clearly mark storm drains, bus stops, and major public buildings

ACTIVITY

 * 1) Have students identify what they think are environmental problems in their area (heat stress, runoff, air pollution, etc)
 * 2) Explain the purpose of different green infrastructure solutions (bioswales, rain gardens filter runoff, green roofs regulate temperature, etc.)
 * 3) Have them find areas to place different solutions (where would be a good street for a bioswale, what buildings would be wide enough for a large green roof?) that pertain to their environmental issues.

How it fits to standard

 * Answer questions by explaining observations of the natural world (K-1)
 * Develop a solution by using a simplified technological design process. Investigate the use of tools (2-3)

Follow-Up
What combination filtered the most? What did the sprinkles, glitter, and beads each represent? Which material is best for filtering out sprinkles? Which is best for beads? Which material filters the fastest?