Retention Ponds Designed for Flood Protection

Retention ponds are artificial structures used to retain and treat contaminated stormwater runoff. They are also used to control flooding and downstream erosion and improve the quality of water in nearby rivers and streams. A retention pond is designed to be built on a slope so that water flows directly into it. The bottom of a retention pond is lined with an impermeable material that keeps the water from seeping out. This prevents the water from running off quickly and allows it to be slowly released.

Driving Question

What purpose do retention ponds serve for a community?

Probing Questions

• Why do you think communities have retention ponds?
• What are some other solutions to treating contaminated stormwater runoff if your community does not have retention ponds?
• How do you think the water gets to retention ponds?
• What happens to the water in a retention pond?
• As you look at the photos, what do you notice about the retention ponds?
• What are the benefits of retention ponds in a community?

Classroom Activities

Students could:

• Research towns in Iowa that have retention ponds and why that community has them.
• Create diagrams to show how storm water runoff gets to a retention pond.
• Create a mini model of a retention pond and visually see how water runoff fills the pond.

Resources

• Town of Milton | Retention Basin DiagramSimple diagram that demonstrates how retention ponds work.
• Strathcona County | Stormwater Ponds: Short video that explains how stormwater ponds function and work in communities.
• Builder Baron: Retention Ponds: Article that provides teacher background on the purpose of retention ponds, and how they work.