The Aswan Dam

Who? what? when? why? how?

The Aswan Dam is along the Nile River in Aswan, Southern Eygpt

High Dam, upstream

constructed 1960-1970

funded by soviet union (wanted Geopolitical support)

4km wide across valley and 35km at its widest

holds 132kmsq of water

designed to regulate annual flooding and store water for agriculture

HEP later

positive economic impacts

more land can be farmed on

lake produced- fishing industry created → 25000 tonnes

water can be used to irrigate agriculture

negative economic impacts

fertile alluvial sediments aren’t released into soil → fertilisers have to be used → $$$

was providing ½ of country’s electricity now only 10%

positive social imapcts

means that houses aren’t flooded → reduction in resettlements

negative social impacts

in order for dam to be build, 100,000 Nubian people had to be resettled

positive environment impacts

provided ½ of the country’s electricity

reliable and constant water supply- multicropping

more successful seeds + harvesting

negative environmental impacts

1. reservoir sedimentation: sediment usually transported downstream is trapped behind the dam, fills up the reservoir so less water can be stored. expected to be full in 900 years

   • dredging of reservoir to mitigate

2. costal erosion: lack of sediment once brought down to the Nile Delta, trapped sediment behind the dam

   • costal protection works along the Nile Delta

3. decreased Marine productivity/ increased salinity: nutrients trapped behind the dam → marine life can’t function the same in saltier water → outflow to atlantic impacted

4. water logging / increased soil salinity: continuous irrigation → groundwater remains high. soil salinity up and distance between surface and groundwater table = small →water drawn by evaporation → smaller concentrations of salt accumulate→ water not flushed → stays saltier and less fertile

   • providing 2m hectares of farmland with subsurface drainage

5. algal growth / decreased water water quality: lower turbidity of water= sunlight penetrating deeper + increased fertilisers in water= Algae → increased costs for water treatment for potable water

6. increase in standing water in irrigation canals- causing bilharzia: parasitic worm living in freshwater in sub/tropical regions water supply channels = more constant

   • provision of clean water and sanitation + health clinics and education