1. Chapter 3 Managing Earth’s Changes
Flooding

2. How can floods be controlled?
Essential Question:
How can floods be controlled?

3. Lesson 1 Vocabulary
flood
storm drain
floodway
levee
dam
reservoir

4. heavy rainfall over many days overflowing rivers severe storms
Floods – occurs when water flows or collect over land that is usually dry.
Floods are caused by:
heavy rainfall over many days
overflowing rivers
severe storms

8. Savannah River
2013 Flooding

9. Tuckasee King
Landing
Clyo, GA
July 2013 Flooding

10. Floods can damage:
crops
destroy buildings & homes
drown people & animals

13. Sediment deposited and changed the shape of the land.

14. Steps to a flood:
Rain goes in the ground
Ground gets very wet
Water flows over the ground = runoff

15. Wetlands soak up extra water.
Nature has its own way of controlling floods –
Wetlands soak up extra water.
There are many laws to protect wetlands. Even with these laws, wetlands are disappearing. Water cannot soak through paved parking lots, roads, and highways.

16. How do we control flooding?
storm drains
levees
dams and reservoirs
floodways

17. Storm Drain = a system of pipes or channels that carry away storm water

18. levee = a wall along the banks of a river or other body of water that serves to keep water behind it.

20. dam = a wall across a river that controls the flow or river water
reservoir = an artificial lake, often formed when water collects behind a dam.

21. full at
330 feet
Thurmond Dam
Clarks Hill, GA

22. People control how much water is in the reservoir
People control how much water is in the reservoir. Dams & reservoirs help keep an even water flow and water supply all year long.

23. floodway = a prepared path for flood water to flow over, often to prevent damage to communities

24. Technology for controlling floods also
has disadvantages.
Levees do not make flood water disappear. Levees send extra water down the river. It may lessen flooding in some areas but increase flooding in other areas.
Levees can fail. Levees can break causing a flood.

25. Flooding damages ecosystems
Flooding damages ecosystems. Sediment deposited during a flood enrich the soil for plants and animals. Controlling floods hurts plants & animals that depend on floods.
Examples:
The Nile River in Egypt once flooded every year. Its valley was very fertile. After the Aswan Dam opened in 1970, farmers began needing fertilizers to support their crops.
In Brazil, the Amazon River regularly floods the surrounding rainforest. Some plants and animals depend on flooding to complete their life cycles. News dams proposed for the Amazon’s future would cause great changes.

26. Everglades – River of Grass
Another example:
Everglades – River of Grass
Began as huge wetlands that covered much of Southern Florida.
The Everglades began to be managed for human needs. Levees, canals, and pumping stations were built. They control floods and provides the water supply for Florida’s population.
This has come with a price!
Water is used on farms and in cities.
The rivers carry dirt, fertilizers, and other unwanted chemicals.
Plant & animal populations in the Everglades have dropped.
The size of the Everglades has diminished.
Today, the government is restoring some of Florida’s wetlands. Canals are being filled and levees are being torn down. The goal is to restore its natural ecosystem.

27. Everglades

28. Let’s Review!
What is this?
floodway

29. levee

30. dam &
reservoir

31. Storm drain