Recent
research conducted in Botswana, one of Africa’s driest countries whose terrain
is punctuated with both the Kalahari Desert and savannah woodland, has
established that the use of water reservoirs, such as dams, in arid areas
increases the risk of drought. The research also established that the use of
water reservoirs in not-so-dry areas, called temperate or semi-arid regions, was
comparatively less likely to cause drought. This information was released in
Gaborone, Botswana yesterday, at a four-day International Conference on Water
Resources of Arid and Semi-Arid Regions of Africa (WRASRA) that kicked off
yesterday and ends on August 6, 2004.
Ninety
delegates from 20 countries that include Africa, Europe, Asia and Australia are
attending the four-day conference.
Researchers
from the University of Witwatersrand, South Africa and from Mantswe Natural
Resources Consultants of Botswana released the information that exposes the
risks associated with establishing reservoirs in arid areas. Both groups had
conducted research to determine the impact of a proposed dam construction on
Botswana’s Thune River in the Eastern part of that country.
The
justification of constructing the dam lies in the fact that it would provide an
alternative source of water for surrounding villages that are heavily dependent
on depleting groundwater resources.
However,
the central question that delegates who are attending the WRASRA Conference
should answer is, should communities in Africa’s arid regions stop using
reservoirs such as dams, which are their major sources of water, when
alternative sources of water such as underground sources cannot cater for both
small and large populations who live in arid African cities and rural areas?
Depleting
Water Resources Threatens Africa’s Development
“Water
plays a key role in the development of world societies and a sustainable use of
this resource is of utmost importance,” said a statement released by the
organizers of the conference, the University of Botswana. “Africa’s water
resources are threatened by the increasing population trend with the resultant
increase in water demand, the stresses of water use for various activities,
desertification, global warming and climate change, and other interventions in
the water cycle by man.”
These
effects are more pronounced in the arid and semi-arid regions of the world and
especially in Africa. It is therefore vitally important that the water resources
in these regions are developed and managed in a sustainable and integrated
manner.
Integrated
management of water resources in the arid and semi-arid regions of Africa
requires a spectrum of efforts from local and community stakeholders to national
and transboundary river basin management. This conference aims at sharing the
best practices of water use and conservation around the globe.
The
statement issued by the University of Botswana said there were no magic
solutions in sustaining water supplies, as neither market forces, military
might, mega-projects nor money alone were able to solve the world’s water
problems.
“On
top of the technical problems, the social aspect of the problem should be
integrated along with conservation and community initiatives to solve the root
problems of water scarcity, which otherwise may incur immense human and
governmental cost,” the statement continued.
A
Conference with Many Interests
The
conference will discuss a wide range of water management issues in arid areas
that include the following: groundwater recharge (natural and artificial),
socioeconomic aspects of demand management, including wastewater re-use customs
and developing communities, climate change and its impact on hydrology, water
resources, carbon and environmental systems and vulnerability and risk
assessment and development of water related risk-mitigating activities.
The
UNESCO Water Affairs-funded International Conference on WRASRA is also expected
to address water stress expected to result from limited water resources,
population growth, increasing demand and pollution and other related risks
resulting in insufficient water supply. The conference will also foster insights
on issues of global sustainable development and set concrete targets to meet the
need for drinking water and sanitation in arid and semi-arid countries.
Costly
Impacts
But
as the conference enters into its second day today (August 4, 2004), residents
of eastern Botswana are anxious to know whether or not the dam construction
project on Thune River will take off.
The
research findings that seem not to be in favor of the dam construction on Thune
River said of the proposed dam, “More water is going to be lost by evaporation
than will be consumed.”
The
dam would also capture all the water, starving downstream communities of regular
water flow and supply.
The
researchers said, “Without releases from the dam, the river dries up for
months a year and the time span between discharges increases considerably. There
may only be one or even no flows down the river in any year.”
They
said this would result in communities based along the riverbanks being
accustomed to a dry river and “can suffer when a flood, which is largely
unexpected, occurs”.
The
researchers have already predicted that if built, the proposed dam will be
nearly half full of sediment within 30 years and its reliable yield would be
much less after 20 to 50 years.
The
researchers said that the effects on downstream rivers would be noticeable,
particularly regarding the low flow. The Motloutse River, into which the Thune
River flows, and further down the Limpopo River, would receive less base flow
from the Thune catchment.
“In
fact, the entire base flow would be eliminated,” said the researchers.
“There is also a potential salinization problem.”
Salinization
is a major problem in irrigated land globally and has severe long-term and often
permanent negative impacts on land, agricultural production and livelihoods,
“if rehabilitation is not undertaken”.
Cumulative
Regional Impacts
The
following negative cumulative regional impacts were predicted if the dam is
constructed on Thune River:
-
increased risks of flooding in downstream areas, e.g. Mozambique,
-
long term deteriorating water quality and possible reduced species composition,
-
increased erosion downstream because of reduced sediment load in the water
(clean water has more energy),
-
less water to downstream users not only in Botswana but also in South Africa,
Zimbabwe and Mozambique,
-
less water to sustain natural systems downstream
-
and contribution to emission of greenhouse gases due to the rotting of
vegetation and carbon inflows from the catchment.
The
researchers said the lessons learnt from the research are that a dam constructed
in an arid area had many pitfalls compared to one constructed in a temperate
area.
Solving
Water Sharing Problems
In
view of the need to promote cooperation between member states within a
particular basin on issues regarding a river, for example the Zambezi River,
countries belonging to the Southern African Development Community (SADC) signed
the SADC Protocol on Shared Water Course Systems on August 28, 1995.
Responding
to a question on whether or not the Zambezi River was being managed
satisfactorily, Professor David Stephenson of the University of Botswana’s
Department of Civil Engineering said, “The Zambezi River is badly managed.”
He referred to corruption, lack of will-power, poor communications and poor data
as reasons for bad management of the river.
The
Zambezi River is shared by eight SADC countries that include Botswana,
Mozambique, Namibia, Zambia and Zimbabwe.
Stephenson
said UNESCO would soon launch a giant research project to be based at the
University of Botswana that will look at international water sharing problems in
SADC.
The
project, expected to last for a minimum of five years and to be funded with
millions of US dollars, will focus on selecting the best managers and ensuring
multi disciplinary integrated planning and capacity building, according to
Stephenson.
At
the international level, water management and use is governed by the Helsinki
Rules on Uses of Water of International Rivers, adopted at the 52nd Conference
of the International Law Association in Helsinki in 1966. An important principle
of the Helsinki Rules is that each basin is entitled, within its own territory,
to a “reasonable and equitable share” in the beneficial uses of water of an
international drainage basin.
*
Emmanuel Koro is an environment and development communication specialist based in Zimbabwe . He is also President of the Sub-Saharan Africa Forum for Environment Communicators (SAFE), which aims to promote the conservation and development views and interests of rural communities in the media. Your emails to will be forwarded to him by contacting the editor at:
ScienceTech@islam-online.net.
