256
C. Faye et al.
1 Introduction
Freshwater is essential for the survival of natural ecosystems and for human activity.
Until the mid-twentieth century, water was considered inexhaustible and accessible
for anyone to use, own and exploit according to their needs (Honegger and Tabarly
2011). These needs vary by economic sector, but all economic development and
industrial activity depend on water. In fact, water withdrawals have increased sixfold since the 1900s, twice the rate of population growth (UNESCO 2006). This has
led to competitive use of water resources among and within sectors, which is a root
cause of many challenges such as political and territorial conflicts, deterioration of
water quality, degradation of the environment, disparities in water distribution and a
decline of access to water resources (Batcho 2008).
Senegal’s total renewable water resources are about 38.97 km
3 per year, of which
about 25.8 km
3 come from within the country. Per capita renewable water volume
is estimated at about 4747 m
3 per year (CONGAD 2009), well below the average of
sub-Saharan Africa (7000 m
3 per person per year) and the world average (8210 m
3
per person per year). Senegal’s internal renewable surface water resources are estimated at 23.8 km
3 /year and renewable groundwater resources are on the order of
3.5 km
3 /year. The overlap between surface water and groundwater is estimated at
1.5 km
3 /year and internal renewable water resources are estimated at 25.8 km
3 /year.
The average annual rainfall is estimated at 686 mm (FAO 2016). The relative abundance of water and the fact that available freshwater supplies are 24.5 times greater
than water consumption (1591 million m
3 in 2000) (FAO 2016) hide the real potential
for water scarcity in Senegal.
The Senegal, Gambia and Kayanga rivers, all of which originate in Guinea,
together irrigate a large part of Senegal. Most surface water reserves are located
in the Senegal and Gambia river basins, whose waters come from the Fouta Djallon
Massif in the Republic of Guinea (Sané 2015). Smaller rivers, the Casamance and
the Kayanga, with intermittent flows, and their main tributaries, the Anambé, Sine
and Saloum and coastal creeks (Fig. 1), complement the water supplied by the large
rivers. A number of other lakes and basins complete the hydrographic network, the
most important of which are Guiers Lake, the bolongs of estuaries and the bounds of
the Niayes region of the northern coast and Ferlo. Available water in any area depends
on the amount of surface and groundwater available from rivers, lakes, reservoirs and
aquifers (Chitambi 2017).
Water scarcity is defined as insufficient water resources to meet long-term average
needs. Variation from the norm results in long-term water imbalances when water
availability from natural recharge is lower than the demand level (EU-Commission
2007). This, in turn, results in a shortage of rapid and reliable access to water
resources for different economic and social groups. The risk of water scarcity and
the potential to pre-empt or effectively address it depends not only on the physical
endowment of water but also on the institutional, technical, political, economic
and infrastructure capacity of a country to manage water to the satisfaction of all
stakeholders (Chitambi 2017).
C. Faye et al.
1 Introduction
Freshwater is essential for the survival of natural ecosystems and for human activity.
Until the mid-twentieth century, water was considered inexhaustible and accessible
for anyone to use, own and exploit according to their needs (Honegger and Tabarly
2011). These needs vary by economic sector, but all economic development and
industrial activity depend on water. In fact, water withdrawals have increased sixfold since the 1900s, twice the rate of population growth (UNESCO 2006). This has
led to competitive use of water resources among and within sectors, which is a root
cause of many challenges such as political and territorial conflicts, deterioration of
water quality, degradation of the environment, disparities in water distribution and a
decline of access to water resources (Batcho 2008).
Senegal’s total renewable water resources are about 38.97 km
3 per year, of which
about 25.8 km
3 come from within the country. Per capita renewable water volume
is estimated at about 4747 m
3 per year (CONGAD 2009), well below the average of
sub-Saharan Africa (7000 m
3 per person per year) and the world average (8210 m
3
per person per year). Senegal’s internal renewable surface water resources are estimated at 23.8 km
3 /year and renewable groundwater resources are on the order of
3.5 km
3 /year. The overlap between surface water and groundwater is estimated at
1.5 km
3 /year and internal renewable water resources are estimated at 25.8 km
3 /year.
The average annual rainfall is estimated at 686 mm (FAO 2016). The relative abundance of water and the fact that available freshwater supplies are 24.5 times greater
than water consumption (1591 million m
3 in 2000) (FAO 2016) hide the real potential
for water scarcity in Senegal.
The Senegal, Gambia and Kayanga rivers, all of which originate in Guinea,
together irrigate a large part of Senegal. Most surface water reserves are located
in the Senegal and Gambia river basins, whose waters come from the Fouta Djallon
Massif in the Republic of Guinea (Sané 2015). Smaller rivers, the Casamance and
the Kayanga, with intermittent flows, and their main tributaries, the Anambé, Sine
and Saloum and coastal creeks (Fig. 1), complement the water supplied by the large
rivers. A number of other lakes and basins complete the hydrographic network, the
most important of which are Guiers Lake, the bolongs of estuaries and the bounds of
the Niayes region of the northern coast and Ferlo. Available water in any area depends
on the amount of surface and groundwater available from rivers, lakes, reservoirs and
aquifers (Chitambi 2017).
Water scarcity is defined as insufficient water resources to meet long-term average
needs. Variation from the norm results in long-term water imbalances when water
availability from natural recharge is lower than the demand level (EU-Commission
2007). This, in turn, results in a shortage of rapid and reliable access to water
resources for different economic and social groups. The risk of water scarcity and
the potential to pre-empt or effectively address it depends not only on the physical
endowment of water but also on the institutional, technical, political, economic
and infrastructure capacity of a country to manage water to the satisfaction of all
stakeholders (Chitambi 2017).