High technology approach (THE ASWAN DAM):
R. Nile's tributaries start in Ethiopia - there is a wet/dry season
R. Nile is effected by this and either floods or dries up
People want a constant water supply for irrigation.
The dam was completed in 1970
It created a lake called lake Nasser which is 560km long

ADVANTAGES
HEP Produced which allows the country to become more developed
HEP station now provides half of the power in Egypt
Irrigation for farmers - crops can be watered all year round
More crops mean more food for the people of Egypt
River doesn't get flooded anymore
More self sufficient - less dependent on outside help

DISADVANTAGES
Billharzia is now caused by snales living in the lake
The delta increases in size by 20 - 30 metres each year
Because of this the land is less fertile
Could harm fish in the sea

Low technology approach (Rainwater harvesting):
Rainwater harvesting is when a small dam is built to stop water flooding off a slope
This makes fertile soil which crops can be grown in
This is good for managing semi - desert conditions
Its cheap
Good for the environment
And has low maintenance
An example is the Jaisalmer district of India