**1. Introduction**

Infrastructures are defined as "networks that enable the movement of goods, people or ideas and allow their exchange in space" [1]. The speed and direction of movement is influenced by their topology and physical form and from this point of view infrastructures are technological objects. Water distribution systems can be defined "as networks connecting water from rivers, lakes and storage sites to homes, farmers' fields irrigation systems and factory outlets empowering water's economic and social functions" [2].

The construction of dams is often linked to state policies seeking to meet the needs of populations. Among these needs, the multiplication of the number of structures is caused by regional development, increased access to drinking water and electricity, flood-fighting and irrigation development. Half of the world's rivers have at least one dam, and hydroelectric power plants produce more than 50% of the electricity consumed in a third of the world's countries [3].

Dams are works that block a section of a valley over the entire width and create a basin in a geological way and thus they usually are considered to be barriers. Its origin may be natural or catastrophic e.g., land slides or avalanches, or it can be the result of a disorganization of the river network with a change in the geomorphological system e.g., moranic or glacial dam. A dam is a project, and hence it has a pre-determined lifecycle after which it may end up being filled, or else by yielding, undermined by the infiltration waters.

Dams are the subject of many claims by members of civil society. The latter often criticize manufacturers and decision-makers for a lack of consideration towards them, a lack of transparency, and unfulfilled promises. From these concerns that animate the populations arise demands, forces to fight against dam projects accused of the flooding of forests, the acidity of water, the sterilization of agricultural land, and expropriations. These infrastructures also include the links between these machines that allow them to function as a system, as well as techniques of organization—companies, accounting, bureaucracies, etc. [4]. These infrastructures, of course, exist in society, and often embody, reflect and, in turn, shape their political, economic and social environment [2].

However, water is considered to be an economic good and is classified as a necessity [5, 6] and the economic motives for increase of agricultural/meat production via bulding dams are as below.

As seen above, if in-country production increases substantially Mauritania an Mali have a chance at a zero/positive BoP and Senegal could halve its negative BoP (**Figures 1**–**4**).

The first dams in the world date back to antiquity. Their objectives were to meet the water needs of the populations and for irrigation. "They are located in the Nile Valley, Mesopotamia, China and South Asia." The oldest known remains come from the Sadd-el-Karafa dam made in Egypt between 2950 and 2750 BC. Even in ancient Rome, more than adequately supplied with water and believing that flowing water was a sign of a high standard of living, water-saving devices (such as taps and storage tanks) were widely deployed [8]. Studies provide information on the mode of operation of dams, their history, as well as their consequences on the fragmentation of watercourses. These impacts are analyzed from several angles, in particular through the transformations of the landscapes, the displacement of populations, the changes of identity, the images projected on the disruptive dam, the economic contributions, the usefulness and the beneficiaries. These analyzes relate to cases of dams already built or projects.

Information also exists on the types of construction. They can be arch dams, gravity dams or buttress dams. This information provides knowledge on the world classification and according to the International Commission on Large Dams (ICOLD). The qualification of "large dam" is attributed to those that rise more than 15 meters above the foundations, according to the said commission.

*Water Resources Management and Hydraulic Infrastructures in the Senegal River Basin… DOI: http://dx.doi.org/10.5772/intechopen.105633*

### **Figure 1.**

*Current Account (BoP) in Current USD [7].*

**Figure 2.** *Imports in Current USD [7].*

Dams are installed with a run-of-river or pumped storage reservoir. They are classified into two categories according to the type of material: concrete dams (gravity dams, buttress dams, arch dams) and embankment dams (earth dams, rockfill dams). A third type combining the first two is called hybrid or compound. ICOLD considers that there are 24,395 large earth dams, 3065 rockfill dams, 6688 gravity

**Figure 3.** *Merchandise Imports Current USD [7].*

### **Figure 4.**

*Food imports as percentage of Merchandise Imports [7].*

dams, 426 buttress dams, 1839 arch dams, 172 multi-arch dams and 2603 of another type. Embankment dams are in the majority and constitute nearly 63% of the total number of dams recorded. It is obviously the oldest type of dam and there are traces of embankment dams dating from the oldest civilizations. In addition, this type of dam can be adapted with many types of foundations.
