botswana/namibia - Cour international de Justice

"The dispute concerns the reach of the Chobe River at Kasikili Island. The length of this reach
of the river is only four kilometres compared with a total boundary length of more than 300
kilometres. Logic requires that the method used for determining the location of the boundary
at Kasikili Island must be capable of being consistently and successfully applied to the whole
length of the boundary along the Chobe River as identified in the 1890 Treaty. The only
definition of the main channel of the Chobe River, including reaches of the river that have
ephemeral, seasonal, or permanent islands in them, is the channel which conveys the largest
proportion of the annual flow of the river. The southern channel meets this requirement while
the northern channel does not." (Memorial, Vol. VI, Part 1, Expert Report, p.4, para. 1.8).
144. Namibia makes no attempt to explain in what way this highly esoteric and opportunistic
definition could have been present to the minds of the negotiators of the 1890 Agreement.
Indeed, the Namibian Memorial (pp.33-44) in examining the preparatory work of the
Agreement, does not seek to establish that the negotiators referred to such a concept.
145. The Namibian Memorial also ignores the fact that, in contemporary international law and
diplomacy, there was a recognition of the link between reference to the thalweg and the
concept of navigability.
146. The question of the interpretation of the 1890 Agreement will be pursued elsewhere
(Chapter 4). For the present, it will be sufficient to underline that the Alexander thesis, with
its exclusive focus upon seasonal flow and non-directional flood flow, pushes aside the
criteria of both configuration (that is to say, bed slope) and depth. In these conditions there
can be no centre of the main channel, because the criterion used by Namibia does not involve
a fixed location either of the river as a whole or a fixed location of the centre of the main
channel. The criterion involves only the identification of the arm of the river which carries a
particular volume of water over a year. The negotiators of the 1890 Agreement, like the reader
of the Namibian Memorial, would be surprised to learn that the identification of 'main
channel' has become so refined that it matters not that the water flow only lasts five months or
that in this period the water is flowing upstream, consisting of flood water backing up from
the Zambezi (see the Expert Report, p.4, para. 1.8; p.5, para. 2.8; pp.9-10, para. 4.4).
(iv) The Namibian Thesis of the 'Main Channel' would seriously reduce the Efficacy of
the 1890 Agreement
147. The scientific evidence will be examined in due course. For present purposes it is
necessary only to relate the consequence of the Namibian theory of the 'main channel' for the
effective application of the provisions of Article III of the 1890 Agreement.
148. The Memorial itself is reticent about the definition of 'the centre of the main channel'
beyond the identification of the 'main channel itself': Memorial, p.57, para. 159. The reader
must refer to the Expert Report to understand the logical consequences of the theory presented
by Professor Alexander. The key passages in the Report are as follows:
"12.6 Morphology of the southern channel. In contrast to the northern channel, the southern
channel is highly sinuous, has an irregular width, and very low, saw-tooth shaped banks that
are only a few centimetres high in places (Photographs on Sheets 21, 22 and 23). Where the
right bank of the southern channel is adjacent to the Chobe Ridge, the bank consists of rock
and consolidated soil protected from erosion by riverine vegetation (Photographs 6 and 7 on
Sheets 21 and 22). The characteristics of the two banks of the southern channel are typical