Okavango Delta Management Plan - Ramsar Convention on Wetlands

and are therefore a part of the normal cycle of the release and absorption of CO2 into and
from the atmosphere associated with fires in African ecosystems.
It is important therefore that there is improved research on the role and effects of fire in the
functioning of the <strong>Okavango</strong> <strong>Delta</strong> ecosystem.
3.2.3.4 Large scale water development
These impacts are discussed in detail in ODMP – Analysis of Water Resources Scenarios
(2006) and these are summarised below.
The basin and <strong>Delta</strong> are presently in a near natural state. To date, land use changes and
abstractions from the basin upstream and the <strong>Delta</strong> have a minimal impact on the <strong>Delta</strong> as
whole, though local impacts may be significant.
Upstream irrigation plans in Namibia and especially Angola are predicted to have a
significant impact. The lower envelope of flooding, i.e. the area that remains flooded
throughout, is reduced by 40% in dry years.
Present and future local surface and ground water abstractions from the <strong>Delta</strong> are
minimally significant, amounting to 0.3% and 0.5% of the inflow respectively. Under future
conditions, the upper envelope of flooding, i.e. the area that may be flooded at some time is
decreased by around 70 km 2, or 0.6%.
The combined water resources developments with climate change have the most severe
impact on the <strong>Delta</strong>. In years with normal inflows, the range of flooded area declines from a
maximum of 12,825km 2
to 4,695km 2
, and from a minimum of 2,944km 2
to 158km 2
.
3.2.3.5 Eutrophication
The <strong>Okavango</strong> River Basin is still in a relatively undisturbed state, also when it comes to
pollution. The entire population of the Basin is in the order of 600,000 people. There are
no major industrial sources of pollution in the basin.
The only urban centres are Menongue and Cuito Carnevale in Angola with an estimated
population of 30,000 and 20,000 respectively, Rundu in Namibia with a population of
42,000 and Maun in Botswana with a population of around 44,000. Locally these urban
areas may cause pollution that would affect the water quality, but when considering the
effect on the entire basin the effects on water quality are negligible (ODMP – Analysis of
Water Resources Scenarios, 2006).
Agriculture is another potential source of pollution in the <strong>Okavango</strong> River Basin that may
discharge nutrients, mainly nitrogen and phosphorus, as well as toxic substances such as
pesticides and herbicides into the river and <strong>Delta</strong> system. The use of fertilisers, herbicides
and pesticides is still very limited in the Basin. The nutrient levels in the <strong>Okavango</strong> River
are very low, and the <strong>Delta</strong> system can be characterised as oligotrophic, except in isolated
pools.
Another pollution issue is the presence of a relatively large number of camps and lodges
that cater for tourists visiting the <strong>Okavango</strong> <strong>Delta</strong>. The Government of Botswana has
adopted a low volume, high cost tourism policy that has so far limited the number of
tourists visiting the <strong>Delta</strong>. In addition, to obtain a license a lodge has to adopt
environmentally friendly management, including proper handling of solid and liquid wastes.
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