River Mississippi

Question 1

Why is the Mississippi controlled?

Answer 1

1. Allows settlements on flood plains. Good for residential and industrial development.
2. Important part of the US transport network.
3. Heep down costs brought by flooding.

Question 2

How are levees used?

Answer 2

Mounds of dirt or concrete walls built parallel to the banks of the river. They contain the rising flood waters and prevent them from flooding the settlements near the banks of the river.
Benefits:
1. Protects settlements.
2. Allows land use on flood plains.
Problems:
1. Prevents natural drainage of river.
2. Expensive to maintain and build.
3. restricts access to the river.

Question 3

How is channel straightening used?

Answer 3

A channel is cut between the two dykes of the river.
Benefits:
1. Cuts transport costs.
2. Controls flow of river.
Problems:
1. The river is meandering again.

Question 4

How are wing dykes used?

Answer 4

Projections out of the bank of the river increases speed at center of river.
Benefits:
1. Increased speed means faster rate of discharge.
Problems:
1. Expensive.

Question 5

How are concrete mattresses used?

Answer 5

Lining banks of rivers with concrete strips to keep flow of river constant.
Benefits:
1. Increases flow of river. Higher discharge.
Problems:
1. Higher discharge may lead to flooding downstream.

Question 6

Is it worth it?

Answer 6

Some people believe the river will always win no matter how we try to control it.