As the global population continues to increase, countries are finding ways to secure water supplies.
Rivers transport water to the sea. Dams block rivers so that reservoirs of water build up behind, rather than drain away. This provides large supplies of drinking water all year round and reduces water insecurity, especially where precipitation may be seasonal. Dams and reservoirs can also prevent flooding, as the flow of the river is controlled, and they can generate electricity through hydroelectric power (HEP). There are over 600 dams in Africa. The Akosombo dam in Ghana and the Aswan dam in Egypt are two of the largest.
When a country has a water surplus in one area and a water shortage in another, supplies can be transferred. This is called a water transfer scheme. Reservoirs collect and store water in areas of high rainfall. Canals and pipes transport the water to rivers or reservoirs in other parts of the country. Water transfer schemes can be found in lots of different countries. The city of Las Vegas is able to exist in the Nevada Desert because water is transferred to it. And the Kielder reservoir in Northumberland supplies water to the cities of Newcastle-upon-Tyne, Sunderland, Durham, Darlington and Middlesbrough via a water transfer.
It is not possible to drink seawater as it contains salt. Desalination plants remove the salt from seawater to make it safe to drink. Desalination plants could solve many of the world's water insecurity issues, but the process is expensive and therefore not viable in some developing countries. The UK has opened its first desalination facilities on the river Thames. The plant removes the salt from tidal water from the river Thames to help the UK during times of prolonged low rainfall and drought.