CS - Kissimmee River, Florida, USA (flood defences/management)

Question 1

Describe the Kissimmee River?

Answer 1

• 165km long, floodplain up to 5km wide
• low lying, wetlands - sustains large pop. of wading birds

Question 2

Flood control

Answer 2

1962-1971:
- canal dec. length of river from 165 to 90km
- channelised - concrete channel, 10m deep
- wetlands drained -14,000 ha, dec. to 2,000: caused 92% dec. in wading birds + fish
- during floods water stays in basin for 1 day instead of 11 (avg.)

Question 3

Problems of flood control

Answer 3

• by 1971, loss of water soaking into aquifers dec. available water
• allowing salt water encroachment from sea
• threatening Orlando water supplies

Question 4

Flood restorations

Answer 4

1999:
- 11,000ha of wetland created
- de-channelisation + filling in to create meanders that were removed in 1962
- cost of initial channelisation = $20M, cost of de-channelisation = $400M
- so cost to get same result as before was $420M