1. Too Much Water! Flooding
Naturally caused by heavy rain & rapid melting of snow
Used to occur every 50 years but now come about every 4 years
Why?? –HUMANS!

2. Too Much Water! Humans increase the severity of flood damage
Removing water-absorbing vegetation especially on hillsides
Draining wetlands that absorb floodwaters & reduce severity of flooding
Living on floodplains
Urbanization
Overgrazing
Deforestation

3. Hillside Before and After Deforestation

4. Reducing Flood Risks
Channelization—section of a stream is deepened, widened, or straightened to allow more rapid runoff
Artificial levees—built along stream banks to reduce the chances of water overflowing into floodplains
Increase the potential for water damage downstream
Flood control dam—storing water in a reservoir and releasing it gradually
Functions only if waters are kept low in the reservoir
Dam operators find it more profitable to keep water levels high for producing electricity

5. Levees