How can river flow be managed – ‘hard

engineering’

A. Hard Engineering Strategies (p117)

• This uses technology in order to try to control rivers.

• They tend to give immediate results but are expensive

• Also in the future they may provide more problems.

How can river flow be managed – ‘hard engineering’

What is a dam and what does it do?

How can river flow be managed – ‘hard engineering’

How can river flow be managed – ‘hard engineering’

Cross section of a dam

How can river flow be managed – ‘hard engineering’

Why are they built?

• Generate electricity• Stop river flooding downstream• Provide water for farmers, factories

or homes nearby.

1. Dams & Reservoirs

• Often part of a multi-purpose project (often to control river flow, produce HEP, supply water, etc.)

• Recreation activities on Lake Powel, USA here• Major example is the 3 Gorges Dam in China.

Costs Benefits

How can river flow be managed – ‘hard engineering’

• Flooded Italian Village

2. Channel (River) Straightening

• This involves digging a straighter shorter channel in areas where rivers meander. The logic behind this is to speed up water flow in flood prone areas, and stop water from "hanging around". 

• This has occurred in York, but can cause flooding in downstream areas -  a knock on consequence.

Costs Benefits

How can river flow be managed – ‘hard engineering’

Example of Hard Engineering: Three Gorges Dam, China

• Reduces flood risk from 1 in 10 yr event to 1 in 100 yr event.

• 1.4m people moved to build dam and reservoir.

• What are the costs and benefits of the scheme?

COSTS BENEFITS