1. Locating the source of a river is a slightly arbitrary process. The Nile has two
main tributaries—the Blue Nile and the White Nile. The White Nile is the
longer tributary, but the Blue Nile, which flows out of Lake Tana in Ethiopia,
contributes the majority (approximately 85 percent) of the discharge. Euro-
pean explorers identified Gish Abay as the source of the Blue Nile in the early
seventeenth century, as it is the spring of the longest stream that leads into
Lake Tana. On the history of European exploration to discover the source of
the Nile, see Bruce (1804); Cheeseman (1936); Moorehead (1960); Moorehead
chapter 1: the eND of a river
1. The remaining 4 percent of Egypt’s water supply comes from groundwater
aquifers underlying the Western Desert and a small amount of rainfall along
the north coast. I do not discuss these sources of water in this book.
2. These figures are estimates from mwri (2005a). Notably, there are consider-
able uncertainties surrounding both how much water Egypt receives from
diﬀerent sources and the sectoral allocation of that water. Estimating how
Egypt’s water is used, for example, is complicated by the fact that water can
be used more than once (see chapter 5).
3. Figures from mwri (2005a).
4. For a more detailed account of Nile hydrology, see Said (1993); Howell and
Allan (1994); Sutcliﬀe and Parks (1999). Tvedt (2004a) oﬀers a useful anno-
tated bibliography of geographical references for the river basin.
5. For a more detailed discussion of downstream countries’ concerns regarding
how the Hidase Dam will aﬀect Nile flows, see Barnes (forthcoming).
6. Ethiopia, Tanzania, Uganda, Rwanda, and Kenya signed the Cooperative
Framework Agreement in May 2010; Burundi in February 2011; and in early