Water Availability in Sudan
Introduction
Water resources in Sudan are very limited.
They comprise rainfall, groundwater and riyer
\f
flows,
all of which are inter-related as part of
the natural hydrological cycle. I
The erratic nature of rain and its concentration
in a short season places Sudan in a vulnerable
situation,
especially in rainfed areas^,Surface
shared with neighboring countries. The Nile
River, which is shared between 10 countries, is
the primary source of Sudan's water. The four
main non-Nile streams are also shared with
neighbors. These are Gash and Baraka which
flow from Eritrea and Azum and Hawar which
are shared with Chad. The largest groundwa-
ter aquifer, the Nubian Sandstone system is
shared with Chad, Libya and Egypt.
The Nile System
Ten countries share the Nile, which dominates
the map of Sudan. These are: Burundi, De-
mocratic Republic of Congo, Egypt, Eriteria,
Ethiopia, Kenya, Rwanda, Sudan, Tanzar
and Uganda.
The Nile is the dominant geographical feature
of Sudan as around 70% of the area of the
1
country is situated within the Nile River catch'
ment area/ On the other hand, although ten
countries share the Nile, about 60% of its
length lies within Sudan. The share of the Nile
waters utilized by Sudan is substantially less
than this ratio. Out of an average annual flow
of 84 billion cubic metres (bcm) of water that
reach Aswan in southern Egypt, 10 bcm were
estimated for evaporates from the High Aswan
Dam,
and 55.5 bcm flow downstream as
Egypt's share according to the 1959 Nile Wa-
ter's Agreement between Sudan and Egypt.
Sudan is allowed to abstract up to 18.5 bcm
according to the agreement, which is 22% of
the Nile flow.
The three main tributaries of the Nile'unite iff
Sudan and the Nile leaves as a single arteiy
through the Sahara Desert to Egypt. The Blue../
Nile and the White Nile join at the capital Khaj-
Hoiim carryingr54"and^7"bcm of water respec-
tively as a long term average, t
320 kilometres north of Khartoum bringing in
about 12 bcm of water. Thus, the annual aver-
age flow of the Nile in central Sudan is around
93 bcm. Approximately 10% (9bcm) are lost
along the journey through the Sahara Desert
leaving 84 bcm of water to reach Aswan. The
Sudanese share, which is 18.5 bcm of the Nile
water measured at Aswan, is equivalent to 20.5
bcm when measured in central Sudan, again
22%
of the flow there.
Sudan has a unique position in the Nile system.
It is a sink, a path and a source of the Nile. It is
on one hand one of the two dry downstream
countries, with Egypt sharing the fate to act as
a drainage basin and a sink for the sediment
and debris flowing down from the highlands. It
also embraces 60% of the Nile within its bor-
ders.
On the other hand, it contributes to the
flow of the Nile from Bahr^EljShazal, Bahr El
Jebel and Pibor basins asTwell
as"
the'seasonal
streams which join the Nile along its journey to
the north.
Sudan has also the potential to increase the
Nile flow through conservation of the river flow
through the wetland areas in its south. If ap-
propriate measures are taken to minimise
envi-
ronmental and social impact in the wetland ar-
eas,
the Nile flow might be increased by an-
other 12 bcm.
y
The amount of sediment carried down to Sudan
during the flood season of one year appears to
be influenced by the rainfall over the upper
catchment during previous years (Hamad and
Mohammed, 1986), It was noticed that when a
wet year follows a succession of dry years, the
sediment concentration is higher than normal
and the flood flow recedes at a higher rate.
This is particularly true for the Blue Nile and
Atbara River flood flows. A succession of dry
years were experienced from 1978 to 1987
while four distinct high floods occurred after
that in the years of 1988,1994,1996 and 1998.
Such a phenomenon has to be addressed in
the policy development and planning process.
Sudan is seriously affected by the dry years
because of its limited storage facilities. Con-
versely, the high floods destroy infrastructure
and increase the effects of sediment and
scourge along the river banks. Mitigation of
floods to alleviate their adverse effects on hu-
man life and property has to be reflected in pol-
icy developments and planning as
well.
I
The combined river is named the Main
which is joined by Atbara fiver at Atbara"lbwH
Sudan National Water Policy
Page 7