Rain Garden

Urban rain garden installed to aid in storm water management.

Possible Guiding, Compelling and/or Anchoring Questions

• What is a rain garden? 
• What purpose do they serve?
• Where do you think a good location would be for a rain garden?

Classroom Suggestions

• Rain gardens help with two things.
  • Reduce the amount of storm water going through the system.
  • Allows more water to infiltrate through the ground. 
• Rain gardens help reduce those drawbacks by holding water in locations where temporary standing water is allowable. This reduces the amount of water going through the storm water system, and allows more water to infiltrate into the ground replenishing the groundwater supply. Bioretention has an added benefit of cleaning the water before it returns to the water supply.
• The purpose of the plants is to slow down the water running across the land, and then use the water that it just collected.
• For most cities, the goal is to get the storm water out into the river as quickly as possible, while keeping erosion low. This reduces the risk of homes and properties flooding, while also creating safer driving conditions. This ideology has some drawbacks though. First, water does not have as much time to infiltrate into the ground. Second, heavy rains can potentially be too much water for the system to handle. 
• In class, begin by showing the picture of the phenomena and give them time to research what rain gardens are. This should lead into the discussion on the concepts and purpose of storm water management. Then go into how rain gardens can help with managing storm water. 
• While researching rain gardens you may come across the term “bioretention.” This is essentially a rain garden with more advancements, and higher goals.
• After students have an understanding of rain gardens, use a location such as your school or a nearby business, and figure out the best location for a rain garden. You may want to wait until it rains and take pictures of the property to see how the water travels.
• You can take this a step further by conducting a cost-benefit analysis. 
• There are many grants available if you want to actually build one.

Related Resources

• Storm Water Management: What storm water management is, and why it is important: This is a thorough introduction to storm water management, and even brings up additional solutions, called “Green Infrastructure.” Both rain gardens and bioretention are explained.
• Council Bluffs, Iowa: Storm Water Management: This website from the city of Council Bluffs discusses the city’s original storm water management goals and how they are trying to improve those methods.
• How to build a rain garden: This is a source on how to build a rain garden.