[MUSIC] [MUSIC] [MUSIC] One of the challenges of international water regulation is to ensure that water resources are shared in such a way as to promote the beneficial use of waters to all States bordering an international watercourse. Of course, whenever we talk about sharing, we talk about the risk of conflict over use. States bordering an international river or those that use it, do not always have the same ambitions, the same objectives, in terms of use. When we discuss the characteristics of these conflicts, a distinction is made between horizontal conflicts of use and vertical conflicts of use. We can identify three horizontal conflicts of use. First, there is a conflict between uses. Often, on the same international watercourse, there are different kinds of uses. For example, hydroelectricity fishing, navigation or agriculture and there may be conflict between these uses. One of the biggest examples of this type of horizontal conflict is seen in the case of Lake Lanoux, a case that dates from the late 1950s when France and Spain were in conflict over the use of Lake Lanoux. France wanted to divert the water for the production of hydroelectric energy and Spain opposed this because they believed that the waters of Lake Lanoux should be used for irrigation. This is the first example of a horizontal conflict of use. When we talk about a horizontal conflict of use, we need to look at the actors. There can be conflict between States such as States alongside an international river or member States of the same river basin organization that may not agree on how the international watercourse should be used. A very good example of this is the Senegal River, shared between Mali, Senegal, Mauritania and Guinea Conakry. Several years ago, Guinea Conakry was not yet a member of the river basin organization that manages the Senegal River known as the OMVS, the Organization for the Development of the Senegal River. Senegal wanted to irrigate the fossil valleys. These are deserted valleys within Senegal, and Senegal wanted to unilaterally use the waters of the Senegal River to irrigate these fossil valleys. And, of course, the two other member States of the Organization for the Development of the Senegal River, Mauritania and Mali, opposed the use of the river for irrigation purposes, especially unilaterally. But this is a horizontal conflict - a conflict between riparian States or States that are members of the same river basin organization. But another type of horizontal conflict that exists between actors is the conflict that occurs between users. We tend to forget that international watercourses, international rivers, are used by people, actors other than States. And these actors can also find themselves in conflict over the use of the shared water resource, and sometimes these conflicts have disastrous consequences. The conflict that took place in the 1990s, in the early 1990s between Senegal and Mauritania, over the Senegal River, a conflict caused by the use rivalry between livestock breeders and agricultural farmers along the river. Talking about horizontal conflicts means that we have to consider conflict between users. And one of the objectives of international water law is to prevent and resolve these conflicts between users by better enabling users to participate in water management. As I said earlier, alongside horizontal conflicts, there is also a category of water use conflicts that could be described as vertical conflicts. In this category, one must first identify the conflicts between the current use of an international watercourse and the future use of an international watercourse. Within customary international law, in principle, there is no hierarchy of uses. I think that's a very important aspect to keep in mind. There is no hierarchy between present uses. There is no hierarchy between present and future uses. However, in practice, States sometimes claim a hierarchy and this can lead to conflict. To illustrate this, there is the example of the Nile. There are two downstream States, Sudan and Egypt, and they believe that their present uses, their current uses take precedence over future uses that may be considered by other States bordering the Nile. This, of course, generates a lot of tension in the management of the Nile. A second category of vertical use conflicts, is the conflicts that could emerge between the uses of States, the uses envisaged by States and the uses envisaged by the actual users. Again, this is not the most frequent type of conflict because today the management of shared water resources is characterised by an interstate dimension. So these are not the most frequent conflicts, but they can still occur especially when talking about water use by indigenous peoples, indigenous communities whose ancestral or cultural practices are linked to water, and who might object to a project proposed by a State on an international watercourse, such as a major dam project, that endangers the ancestral practices of these communities. So here, conflicts of use also exist but when a State is against a user or against a local community, these are known as vertical conflicts. So these are the main types of use conflicts found in practice. In conclusion, there is even a third category to consider - the diagonal conflict of use. Why? Because in this, the conflict is not over the actual use of the water resource itself. A recent example of this is when Costa Rica wanted to build a road along the San Juan River which was opposed by Nicaragua who considered that the construction of this road would impact the river and its uses. As the river was not directly concerned, the conflict here did not relate to use, as such. However, building a road alongside the river is a diagonal use that can lead to conflicts around and at the periphery of the river. So when we think of conflicts over how water resources are used today, we must also have a systemic vision, an ecosystemic vision. It is not only the resource of water that can lead to conflict, but also the environment that makes up this resource: soils, forests, land, air. And this type of conflict can be related to the environment of the shared water resource. This was the case in Costa Rica when they wanted to build a road along the San Juan River. This could be qualified as a conflict of water use because the construction could impact how the water resource is used, however, here, we would rather talk about diagonal conflict. [MUSIC]