The Volta Convention: an effective tool for transboundary water resource management in an era of impending climate change and devastating natural disasters?

• Author: Matthews, Megan

1. INTRODUCTION

   The Volta Basin is a West African watercourse encompassing six riparian states, some of the most impoverished nations in the world. The basin region has recently been plagued with devastating parasitic diseases, floods, droughts, and water shortages. As the global temperature begins to shift, the rainy seasons in the basin have become more sporadic and intense, leading to both flooding and droughts. Recent deluges have spurred conflicts between states, springing from accusations of dam letting without prior notification. The inundations left thousands homeless and destroyed thousands of hectares of farmland. These extreme weather events are projected to increase in occurrence and severity due to climate change, which will also cause sea level rises, elevated regional temperatures, and decreased annual rainfall. The cumulative effect of these imminent environmental stressors will likely cause extreme water stress, food shortages, economic duress, and, ultimately, transboundary conflict between the riparian states relating to shared water resources. In the face of impending climate change disasters and water shortages, the basin states must take swift and immediate action to avoid their continued status as perpetual victims.

   Transboundary water resource management has been nonexistent within the basin until recently. In 2007, the Volta Basin states signed and subsequently ratified a convention, the purpose of which is to promote social and economic growth within the region and to effectively manage the Volta River and its tributaries. This instrument was the first and most important step in creating a cooperative effort for the basin's water resource management. Unfortunately, the treaty is severely lacking in many of its substantive and procedural obligations. If these states take swift and immediate action within their transboundary water management program created by the new treaty, the basin states may prevail in protecting their populations and sovereign interests from the impending dangers of the changing climate.

   This paper will begin in Part II with a physical description of the Volta Basin, including the tributaries of the watercourse and their relation to the riparian states of the basin. Part III will examine the historical uses of the basin's water, beginning with the pre-colonial and colonial eras, followed by post-colonial and modern uses. This section will include a detailed discussion of the various social, economic, and other pertinent obstacles caused by water issues that affect the riparian states, particularly those related to climate change. An analysis of the development of the international legal regime relating to the watercourse will follow in Part IV. Part B of this section will specifically treat the recently ratified Volta Convention and analyze its strengths and shortcomings in comparison to the United Nations' Convention on the Law of Non-Navigable Uses of International Watercourses. Then, Part V will argue that the Volta Convention's current obligations are insufficient to combat the impending natural disasters associated with global climate change. Finally, Part V concludes that the Volta Convention has the opportunity to be an effective tool for transboundary water resource management to protect the basin state populations from the dangers of climate change, only if substantial changes are made to the treaty.

2. PHYSICAL DESCRIPTION OF THE WATERCOURSE AND BASIN STATES

   The Volta River Basin is the ninth largest basin in Africa, covering over 400,000 [km.sup.2], an extremely sizeable basin when considering that the category for "large" basins begins at 10,000 [km.sup.2]. (1) Six riparian countries share the Volta Basin in West Africa: Burkina Faso, Ghana, Togo, Benin, Mali, and Cote d'Ivoire. (2) Burkina Faso and Ghana occupy a majority of the basin, 43 percent and 42 percent respectively. (3) The 15 percent remainder rests within the four remaining riparian states, of which Togo occupies 6 percent, Benin 4 percent, Mali 3 percent, and Cote d'Ivoire 2 percent. (4) The Volta Basin stretches from its most northern point, in Mali at 14[degrees] 30' N, to its most southern point, in Ghana at latitude 5[degrees] 0' N. (5)

   The basin is drained by the River Volta and its four main tributaries: the Black Volta, the White Volta with the Red Volta as its tributary, the Lower Volta, and the Oti. (6) The Black Volta's headwaters originate from the Sourou River in Mall and the Mouhoun in Burkina Faso, which join together in Burkina Faso. The Black Volta then runs contiguously along the Burkina Faso and Ghana border, and flows downstream to Ghana, contributing 18 percent of the total annual flow to the basin. The Sourou dries up for approximately two months a year. The mean annual flow of the Black Volta at Bamboi is about 200 [m.sup.3]/s, of which approximately 57.4 percent originates from Ghana, and its mean annual runoff is 7,673 x [10.sup.6] [m.sup.3]. (7)

   The White Volta's headwaters begin as the Nakanbe River in Burkina Faso and the river travels south into Ghana. Its mean annual flow is approximately 300 [m.sup.3]/s and its mean annual runoff is 9,565 x [10.sup.6] [m.sup.3]. The main tributaries of the White Volta are the Red Volta and the Sissili, each with their source in Burkina Faso. Both the Red Volta and Sissili dry up for approximately two months a year. These tributaries contribute 20 percent of the total annual flow in the Volta Basin.

   The Lower Volta flows predominately within Ghana, occupying an area of 59,414 [km.sup.2], but also enters into Togo briefly, yet only encompassing 3,237 [km.sup.2] within Togo. (8) The three other basin tributaries converge into the Lower Volta before emptying in to Lake Volta, contributing to the Lower Volta's mean annual runoff of 9,842 x [10.sup.6] [m.sup.3]. (9)

   The Oti River comprises only 18 percent of the total catchment in the Volta basin, (10) but because the Oti's sub-basin has steep topography and comparatively higher rainfall than the other countries in the basin, it contributes 30 percent to 40 percent of the Volta River system's annual flow. (11) The Oti River originates in the Atakora mountain range of Benin at an altitude of 600 m and its tributaries and basin primarily rest in Togo, Burkina Faso, and Ghana. (12) After leaving Benin, the river travels into Burkina Faso, then moves southwest to form the border between Burkina Faso and Benin, before dropping into Togo, and then Ghana. (13) Due to the high level of rainfall it receives, the river does not dry up in the winter season and has an annual average flow of 100 to 300 [m.sup.3]/s, with a maximum flow of 500 [m.sup.3]/s. (14)

   The main tributaries of the Volta Basin discharge into Lake Volta, located in Ghana, and the total annual runoff from the Volta and its tributaries is approximately 56.4 billion [m.sup.3] of water. (15) The Volta Lake is the largest man-made lake in the world, created as a reservoir by Akosombo Dam. (16) Its surface is near 8,500 [km.sup.2], the average depth is about 18.8 m and the greatest depth is 90 m, with a shoreline of about 5,500 km. (17) The lake's total volume at full supply level is approximately 150 billion [m.sup.3]. (18)

   The climate within the basin can be divided up into three basic zones: humid tropical, tropical transition, and dry tropical. (19) The humid tropical climate, which is characterized by two distinct rainy seasons, is the most southern zone within the basin, encompassing the southern regions of Cote d'Ivoire, Ghana, Togo, and Benin. (20) The northern parts of Cote d'Ivoire, Ghana, Togo, and Benin occupy the tropical transition zone, as well as the southern tips of both Burkina Faso and Mali. (21) The tropical transitional zone has two less distinct rainy reasons. (22) Burkina Faso and Mali occupy the dry tropical zone, and further extend into the Sudan, Sudan-Sahelian, and Sahelian zones. (23) The dry tropical climate consists of two seasons: a longer dry season and a shorter wet season, which peaks in August. (24)

   The predominant sources of water in the basin are rainfall, streams, rivers, lakes, groundwater, and man-made water storage facilities, such as dams and reservoirs. (25) The mean annual rainfall in the Volta Basin ranges from 1400 mm in the southern part of the basin to 400 mm in the north. (26) The majority of the mean annual rainfall in the basin occurs during the rainy season, which peaks in July and August each year. (27) Due to climate change, however, the rainy seasons are shifting, becoming shorter, and more sporadic. (28) The basin region is plagued by droughts in the dry season and increasing variability in the rainy season, which is progressively augmenting water stress. (29)

   The mean average annual evaporation of the basin ranges between 1400 mm and 3015 mm, (30) a relatively high level of evaporation in comparison to the level of precipitation the basin receives. The high level of evaporation is potentially increasing the rate of desertification in the region; particularly in Burkina Faso where the minimum rate of evaporation is 1900 mm/yr. (31) Total annual input into the Volta Basin from precipitation is approximately 407,600 mcm. (32) The net runoff from the basin is 38,900 mcm/yr, approximately 10 percent of the total input from precipitation. (33) This rate of runoff indicates that a comparatively reduced rate of recharge from surface water is occurring in the region, perhaps due to evaporation, storage of the water by man-made facilities, and other factors.

   Groundwater is not a significant resource in the basin, mostly due to the low primary porosity of the region's sediment, known as the Voltaian Formation. (34) Groundwater and aquifers occur marginally from "the development of secondary porosity as a result of jointing, shearing, fracturing and weathering" of the sedimentary formation. (35) Unfortunately, use of shallow aquifers in the region, when accessed by...