Save Some Water for Later. Dam building in Egypt.

In this entry, I will focus on the role of another cutting-edge solution to increase water and food production. This method is the use of dams. I will first explore how dams function through the Aswan Dam, Egypt (fig. 10). I will also explore dams' efficiency and whether they could be a solution for other African nations. 

 

What are dams? 

Dams come in various shapes and sizes, ranging from a small-scale regional dam to 'mega-dams'. However, regardless of a dam's form, the function remains relatively the same. A dam is a structure used to control river flow; this structure holds water in a reservoir until it is needed (Jones 1997). By capturing water in the reservoir, water can then be released during low flows, replicating the natural state of a river, which is essential especially for farmers and municipal populations (Jones 1997; Davie 2002). 

 

The Aswan Dam, Egypt:

An iconic example of a ‘mega-dam’ has been the Aswan High Dam located on the Nile in Aswan, Egypt (fig. 1-10). Rainfall is imperative in Egypt, as it facilitates yearly floods. These floods contain valuable nutrients and alluvium deposits which the nation’s agricultural sector relies upon (Sutcliffe and Parks 1999; Strzepek et al. 2008). Unsurprisingly, rainfall is hugely variable along the Nile. Hence some years, floodwater is far too high, causing crops and soils to be destroyed (Monsef et al. 2015). In contrast, some years see low rainfall, therefore causing drought, subsequently limiting agricultural outputs (Smith 1990). This is where the Aswan High Dam comes in. By collecting and storing water when there is a surplus of river flow, the Aswan Dam can release water periodically according to local needs. Statistics suggest that the dam releases 55 km³ of water per year, with 46 km³ going to irrigation channels (Abu-Zeid and El-Shibini 1997). This release of water has been imperative for Egypt's agricultural industry, especially during low rainfall events. The country can capitalise on rice production, beans, wheat, but most notably cotton, even when rainfall is limited. Likewise, the dam has also been invaluable in producing electricity. At its peak in 1998, the dam produced 15% of Egypt's electricity. In today's world, the dam now can generate approximately 2.1 gigawatts of electricity across its 12 generators (Ibid 1997; Biswas and Tortajada 2011). So, many people might ask why aren’t other African countries creating dams if they are so useful? Building a dam like the Aswan comes with a whole host of challenges; here are just a few:

 

Drawbacks:

The Aswan Dam's cost was estimated at $1bn, with much of the money coming from international lenders, subsequently adding to Egypt's national debt (Ibid 1997).

- Building the Aswan Dam was only possible as there was a river to build it on (the Nile), for other regions without large rivers, dam-building is out of the picture.

The Aswan Dam caused significant impacts on marine life, especially when large animals attempt to migrate through the Nile (Zeid 1989).

- The Aswan Dam has impeded the flow of valuable nutrients in the form of sediment, which is crucial for agriculture dams (Ibid 1989).

Figure 10: The Aswan High Dam, located in the city of Aswan along the Nile River (Bratinica n/a)

In conclusion, dams such as the Aswan High Dam can prove useful for increasing water and food production, primarily when limited river flows inhibit water access for irrigation. By reading this entry, one may think that building a dam is the best solution to solving food and water storages. However, upon review, dams are not always appropriate, owning to their monetary and ecological costs. Even though they may appear efficient in increasing agricultural production, altering the natural state of a river can often prove disastrous. Is there a better solution that African countries can use regardless of their geographical location? That is where ‘virtual water’ comes in, and that is what the next entry will focus on, so stay tuned!