Dam engineering in Algeria:

progress, needs and prospects

A. Ouamane, University of Biskra, Algeria
This paper describes the potential for future water resources development in Algeria, as well as some key
aspects of dam engineering, past and present. One current issue discussed is reservoir siltation, which is
reducing the storage capacity of dams.

I
n terms of water resources, Algeria is among the Fig. 1. Map showing
poorest countries of Africa and the world. the distribution of the
hydrographic basins
Therefore, one of the constant preoccupations of
in Algeria.
the relevant authorities is to try to resolve the delicate
balance between maintaining water resources and
meeting water needs.
To reach a satisfactory level of security in water sup-
ply, it would be necessary to commission between 15
and 20 × 109 m3 of storage per year by 2025. This is a
major challenge, considering currently only 7 × 109 m3
is developed each year.
Another challenge is that major erosion which
affects the northerly plains is decreasing both the agri-
cultural potential of the country and the capacity of
water resources that can be mobilized.

1. Runoff potential of Algeria

Algerian territory covers about 2.4 × 106 km2.
However, 90 per cent of this area is desert, where pre-
cipitation is virtually non-existent. The potential of
renewable water resources is concentrated in the north
of the country, which contains basins dependent on the Table 1: Spatial distribution of the surface waters in Algeria
Mediterranean Sea and those of the high plateaux. The
rainfall in this region varies from 200 mm/year on the Hydrographic basin (1) (2) (3) (4) (5) Total
high plateau to 1600 mm/year on the mountains of the Resources (106m3/year) 1025 1840 4380 4500 600 12.34
Atlas Tellien bordering the Mediterranean. Besides Percentage 8.7 15.7 37.3 38.3 0.48 100.0
this north-south variation, one can observe an increase
in precipitation from west to east.
The runoff potential is governed by Algeria’s arid to
2. Mobilization of the runoff
semi-arid climate. The potential is thus very low, and The construction of dams to exploit the country’s
corresponds to only around 20 × 109 m3, of which it runoff became a major concern throughout the 19th
would only be possible to develop about 12.4 × 109 m3. Century. The first dam built in Algeria was Meurad,
The Algerian territory is sub-divided into five hydro- Foum El Gherza
graphic basins (see Fig. 1 and Table 1). This helps to dam (1950).
correlate resources with areas of greatest need. The
basins are:
• Oranie - Chott – Chergui;
• Chellif – Zahres;
• Algérois - Hodna – Soumam;
• Constantinois - Seybouse Mellegue; and,
• the South.
The spatial disparity of water resources indicates that
the first two of the hydrographic basins listed above
(which represent about 35 per cent of the total surface
of the Atlas Tellien mountains), receive only around 8
per cent of the total runoff.
The Constantinois - Seybouse Mellegue basin is the
region richest in water resources, receiving nearly 39
per cent of the annual flow volume of the country.
In the South, the availability of runoff is also low.
However, sub-terranean water resources are substantial.
To resolve the delicate balance between water
resources and meeting water needs, the authorities in
Algeria have been forced to mobilize the maximum
potential of water available, which combines non-con-
ventional, subterranean, and surface aters. Sarno dam (1954).

Hydropower & Dams Issue Six, 2009 1

 Table 2: Classification of dams in terms of capacity

Capacity Number of Total capacity

(106m3) (106m3)

>500 2 1610
500 > V > 250 4 1360
250 > V > 200 4 889
200 > V > 100 16 2278
100 > V > 80 4 342.1
80 > V > 60 6 425.1
60 > V > 40 11 535.5
40 > V > 20 8 229.5
V < 20 10 107.3
Total 65 7776.5

View of Beni Haroun, Algeria’s largest dam.

More than ten major dams are currently under con-

struction.
The Algerian dams are of average capacity, the
largest being: Beni Haroun, with a capacity 960 × 106
m3; Koudiat Acerdoune (650 × 106 m3); Gargar (450 ×
106 m3); and, Djorf Torba (350 × 106 m3). Experts have
stressed that the hydrological conditions of Algeria do
not allow for dams of very large capacities.
Fig. 2. Increase in constructed in 1861. Other dams were built during the To reduce the deficit of water storage, the Algerian
storage capacity. period 1846-1885. However, these experienced a Government foresees the construction of 110 more
number of design problems, because the necessary dams in the future.
engineering techniques had not yet been fully mas- Of the total of 65 large dams in operation, the break-
tered. From 1930, dams with larger capacities began down of types is as follows: 42 are earthfill, eight are
to be built. rockfill, five are concrete gravity, two are arch, four are
The 11 large dams built before 1962 (the year of the multi-arch, three are RCC dams, and one is masonry.
Algeria’s independence ) had an initial capacity of The last seven years (2003-2009) saw an important
about 1 × 109 m3 and regulated an annual volume esti- evolution in the mobilization of the runoff, estimated
mated at about 600 × 106 m3. It is noteworthy that by at 2243.15 × 106 m3 (29 per cent of the total capacity).
1962, silting of reservoirs had affected 20 per cent of This progress was achieved through the construction
the total storage capacity, which totalled about 200 × of ten dams with large capacities, including Bein
106 m3. Haroun and Koudiat Acerdoune dams.
Since 1962, a further 54 dams with a capacity of at The 65 dams in operation are distributed between the
Fig. 3. Evolution of least 10 × 106 m3 each were cponstructed, increasing various hydrographic basins as shown in Table 3.
the number of damd the total storage capacity of dams in Algeria to about
in Algeria. 8 × 109 m3 (see Table 2).

Cheurfas II dam (1992).

2 Hydropower & Dams Issue Six, 2009

 Table 3: Dams in operation by hydrographic basin

Hydrographic basin Number Capacity Percentage

(106m3)

Oranie (1) 13 768.7 9.89

Chéliff-Zahrez (2) 14 2109 27.12
Algérois-Soummam-Hodna (3) 15 1711.35 22.00
Constantinois-Seybouse-Mellègue (4) 19 2612.45 33.59
South (5) 4 575 7.40
Total 65 7776.5 100

Ksob dam (1976).

Monitoring and implementation of plans and pro-

grammes for the mobilization and transfer of surface
water resources is the responsibility of the National
and Gargar (1988) 20 per cent. This situation trans- Fig. 4. Reduction of
Agency of Dams and Transfers (ANBT).
lates to a loss of storage which involves the non-satis- the initial capacity
According to the latest evaluations, the dams with a of dams by the
capacity of more than 10 × 106 m3 in operation allow faction of water needs.
silting.
for the regulation of an annual volume estimated at 4
× 109 m3 of water, representing about one third of the 4. Possible solutions for the problem
exploitable potential. This does not take into account of siltation
the volumes used for the hydropower production at To remedy the problem of silting, several solutions
the Erraguene and Ighil Emda dams. have been recommended. These are generally cura-
tive, such as the construction of new dams, heighten-
3. Reservoir siltation ing of dams, the construction of desilting basins
The climate in Algeria is characterized by rainfall of upstream of dams, dredging by various processes, and
short duration and strong intensity, which generates so on. All these remedial measures have been used in
floods, mainly in the autumn, and causes the erosion Algeria. (Reconstruction of Fergoug and Cheurfas
of young relief in areas where vegetation cover is dams, heightening of Bakhadda, Hamiz, Zardézas and
poor. As a result, the silting of reservoirs can occur Ksob dams, a desilting basin for Boughzoul dam, and
rapidly, and this leads to a significant loss of storage dredging at the Fergoug, Zardézas and Foum El
capacity. The last bathymetrical survey carried out by Gherza dams).
the national Agency of the Dams, in 2004, showed that The solution of heightening the sill weirs by adopt-
siltation had reached a volume of 1.05 × 109 m3, rep- ing a P.K.Weir represents an interesting and economic
reseenting 13.5 per cent of the original total capacity. alternative. A summary study of this solution for 13
This has reduced total storage capacity from 7.78 to Fig. 5. Rates of
Algerian dams showed that this solution could recu- siltation of dams in
6.75 × 109 m3 (Fig. 4). perate 400 × 106 m3 at a very low cost. operation.
The average rate of silting of dams built before 1970
is 57 per cent, which is 8.2 per cent of the total initial
capacity of Algerian dams. The rate is less significant
for dams built during the period 1970 to 1990, for
which the average is 15.3 per cent, representing 4.4
per cent of the initial total capacity. For dams built
over the last 20 years, the average rate of silting rep-
resents only 1.5 per cent, that is 0.6 per cent of the ini-
tial total capacity (Fig. 5).
The rate of silting of dams in operation increases
with the age of the dam. In this sense one can find
some cases of dams for which the rate of silting is
high, in particular: Fergoug (1970) 78 per cent, Foum
El Gherza (1950) 68 per cent, Boughzoul (1934) 63
per cent, Ksob (1976) 60 per cent, Ghrib (1939) 59 per
cent, Ighil Emda (1954) 55 per cent, Oued Fodda
(1932) 54 per cent, Bou-Hanifia (1948) 48 per cent,
Zardezas (1974) 40 per cent, SMBA (1978) 36 per
cent, Mexa (1998) 35 per cent, Bakhadda (1936) 28
per cent, Hamiz (1935) 26 per cent, Beni Amrane
(1988) 26 per cent, Djorf Torba (1969) 26 per cent,

Hydropower & Dams Issue Six, 2009 3

 5. Conclusion Bibliography
The water resources of Algeria are limited and distrib- CNES, « L’eau En Algérie : Le Grand Défi De Demain» B.O.
N°9, Pp. 105-149, Mai 2000, Travaux De La Commission
uted iunevenly throughout the country. This makes it Aménagement Du Territoire Et De L’environnement.
difficult to mobilize and manage these resources. In Ministry of Water Resources, “Dams of Algeria”2008.
spite of these challenges, experts are endeavouring to
reduce the water deficit and reach a more balanced
distribution of water resources throughout the country.
The Algerian Government has set up a strategy of
development for the water sector, based in particular
on mobilization of runoff and subterranean water
resources, as well as combatting the loss of water
resources through rational management.
This strategy is based on a programme of develop-
ment, in particular on the construction of dams, and
the interconnection of several dams via water transfer
systems to all the regions of the country. A. Ouamane
The runoff potential is estimated at 20 × 109 m3, of
which 12.4 × 109 m3 is exploitable. At present, Algeria
has 65 dams which had an initial capacity of about 8
× 109 m3 (that is, 75 per cent of the exploitable Dr. A. Ouamane has been a lecturer since 1986 in the
resources), but this capacity has been reduced to 6.7 × Hydraulic Department of Biskra University in Algeria. He is
109 m3 because of silting, which exceeds 1 × 109 m3. Head of Research in the Laboratory of Hydraulic Planning
To reach a sufficient rate of water resources devel- and Environment. He has conducted various theoretical and
experimental studies on shaft weirs, stepped weirs, labyrinth
opment, several dams are under construction or study. weirs and the P.K.Weir.
Their commissioning will provide a total storage
capacity of about 10 × 109 m3. However, the problem University of Biskra, Department of Hydraulic Engineering,
of reservoir sedimentation remains a significant chal- BP 918, RP 7000, Biskra, Algeria.
lenge, and will require more attention in the future. ◊

4 Hydropower & Dams Issue Six, 2009