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Tell Tale Signs
Interview Transcript
Dr Richard Beilfuss
Hydrologist, International Crane Foundation
"Well the Zambezi is the economic, the
social, the cultural lifeline of Southern Africa - it's in
8 southern African basin countries from the Congo in Angola
- the western part of southern Africa all the way down to
the coast in Mozambique and especially what are called the
lower countries, Botswana, Namibia, Zimbabwe, Zambia, Mozambique...
they all want and need Zambezi water and even countries as
far as South Africa have their eyes set towards using Zambezi
waters in the future so it's extremely vital to the whole
economy of Southern Africa and by far the most important body
of water in Southern Africa."
"Cahora Bassa dam was completed in 1974
and with its closure it has really fundamentally altered the
flooding regime of the lower Zambezi valley now - most years
you get none of the mean annual flood that used to occur historically
especially the main flood that would come down about February
or March each year and inundate areas along the Zambezi and
it was those floods that really fed the subsistence agricultural
system and fisheries of the lower Zambezi which depended on
those floods each year coming down the Zambezi to adjust their
economic livelihoods."
"One of the big problems with the management
of Cahora Bassa dam is that each year they need to create
capacity to store a possible large flood that could overtop
the dam and so in order to do so they often have to release
waters during dry season especially in wet years they have
to release waters downstream to make storage capacity available
in the dam and its those dry season floods that have really
been a terrible problem for farmers and fishers downstream
because they can come at any time of the year they can come
in August or October and they can come and wash out crops
along the lower Zambezi, it's quite a big problem - so not
only is there the loss of floods during the normal time of
peak flooding there's also the potential for floods at any
time of year - In temperate climates it would be something
like getting snow in the middle of the summer at a time when
you never expect it just coming down - it completely alters
the way people can perceive their own environment."
"People farm all along the banks of the
lower Zambezi and they farm in a way that's based on the idea
that when the peak floods come they'll plant their crops as
the waters receed back towards the river so they're anticipating
when they plant their crops that they've seen the peak flood
of the year. What happens with off season floods then is that
the flood waters will come up and drown up their crops and
it has a terrible impact if they loose their crops for the
year that’s their livelihood - they can starve they're
forced to sell their labour to get income elsewhere so they
can buy food and so on so its quite hard on the subsistence
economy - and by the same token for the fisheries, they depend
on low flows during the dry season so that they can harvest
fish from rivers, when they get high flows during the dry
season infact it makes the fisheries more difficult for them."
"Under natural or historic conditions
Zambezi water would flood over water each year and during
that period fish would move out from the main Zambezi channel
out into the floodplain where they spawn and that's really
the productivity of the fisheries is out in the floodplain
- then as the floodwaters recede back to the main river the
fish are trapped in various lakes on the flooplain and the
local people would move in and fish, heavily fish in those
bodies of water and catch a lot of fish at the end during
the dry season so it was very vital to the economy to have
people spread out all over the floodplain harvesting fish
- what you get now since the construction of the dam is very
infrequently do waters flood over bank and move into the floodplains
infact the 2001 flood was the first time since 1978 that you
really had a big spill of water over into the floodplain so
with that loss the fishery has really gone down and local
people throughout the lower Zambezi complain that the fish
are getting smaller and smaller and more difficult to catch
- their reproduction is so much lower than it would be under
a normal system of floodwaters moving out into the floodplain
and then back in the dry season.
"What we're trying to show in our work
is that its very possible to release a smallish but significant
flood each year at normal time of peak flooding sometime between
January and march each year and that flood can be released
and people would go back to adjusting their fishing and agricultural
activity with that kind of flood each year and that’s
really the key to this - there's significant / sufficient
water available in the Zambezi to release a flood like that
it just needs political will to do so."
"Throughout the millennia floods came
down each year down in the lower Zambezi usually during the
period during about January to March and those floods inundated
the planes of the lower Zambezi stimulating the fisheries
supporting flood recession agriculture and supporting livestock
grazing along the banks and so on and what we really want
to do in essence is recreate that flood - there is sufficient
capacity in the dam and in the waters of the Zambezi for the
dam to release a flood each year sometime during that same
natural period from between January to March to release waters
downstream that will once again inundate the plains of the
lower Zambezi, we're not talking about huge floods which occurred
in years like 2001 in the Zambezi but moderate floods that
people can make social and economic use of and those same
floods are vital to get into areas like the Zambezi delta
and create good flooding conditions for wildlife."
"This is the mangrove area where the historic
Chinde was, in earlier times ya - completely gone now - after
all here we're seeing quite dense strips of coastal mangrove
but there's an interesting phenomena along the coastal strip
you see large areas of mangrove that have died off - there's
a bit right there and the mangroves are dying back from the
coast and we've been observing this for about 40 years here
different scientists have documented it and the thinking is
that in part its due to a lack of silts in the Zambezi that
the dams in the upper Zambezi block the silt from reaching
down to the coast that there's no more accreation of silt
along the coast or at least it's greatly reduced and the mangroves
are slowly dying back because they can't rebed on the seaward
side."
"Well mangroves are important for a number
of reasons - they support a lot of the biodiversity along
the coast but most significantly they support both subsistence
and national economies, people use mangroves here for quite
a few products especially for building materials for houses
and these mangroves are also where the shrimps and prawns
breed and prawn is one of the most important export industries
of Mozambique and quite good studies have estimated the economic
cost of...
the coastal mangroves support the prawn industry
in Mozambique and people have estimated that the reduced flooding
in the mangroves the regulated flooding below the dams probably
costing about 20-30 million US per year in export sales of
prawns in this region so its quite important for the national
economy of Mozambique."
"OK you see that there - quite an extensive
area of mangrove die off right there - and you see there's
pockets along the coast where the mangroves have died off."
"The area most affected by Cahora Bassa Dam in terms
of wildlife and natural vegetation communities is the Zambezi
delta region the Zambezi delta is a huge floodplains archaic
system about 18,000 square kilometres and that area's really
been cut off from flooding over the course of the last century
and especially from large dams on the Zambezi like Cahora
Bassa - and with that loss of flooding the carrying capacity
of the wetland is really going down - its ability to support
the large heards of buffalo it supported in the past, large
heards of waterbuck and of zebra and so on, and so what you
see now is that many of the channels of the delta that used
to carry waters out into the plains have now become choked
up with vegetation. They look like green lines running through
the plains now and you see very little water in the channels
and that loss of conveyance is really contributing to the
drying out of the delta now."
"The Zambezi delta supports a major hunting
industry - safari hunting. The hunting actually contributes
money back to the local communities as well as people come
in and pay quite a bit of foreign exchange. Hunting opportunities
for buffalo and other species - the meat from those hunts
is distributed among the local communities and so there's
opportunities for gain there and as the carrying capacity
of the Zambezi delta is lowered then the opportunities for
hunting are lowered aswell there's fewer species that can
be hunted on an annual basis because there's fewer species
? on the wildlife there and that can have quite a serious
economic impact on the delta region."
"One of our big interests in the Zambezi
delta region is the wattled crane because we feel the wattled
crane is kind of a flagship species and an indicator species
for many of the changes that have come to the Zambezi delta
and really to the whole of the lower Zambezi. The wattled
crane is dependent on the annual floods in two different ways
- their breeding productivity - their annual breeding is timed
to the floods so that they breed during peak floods and raise
their chicks on the pulse of life that grows after the peak
floods occur; also their main food source which are the underground
tubers of sedges the underground growing rhizomes of sedge
species, that food source is completely dependent on the annual
flood pulse on both the wet season and the dry season that
are pronounced - so as those floods disappear the food source
and the breeding stimulus for the cranes disappear - the birds
stop breeding and slowly vanish from the delta - and we feel
the wattled cranes are really an excellent indicator species
for many species that live out in the delta that depend on
the annual floods of water - because cranes are large charismatic
very well known among local villagers, they're kind of symbolic
for a lot of the smaller species that noone knows about in
the system - small birds that are out in the floodplain that
noone ever sees."
"I think our challenge as social scientists
economists as ecologists is to demonstrate that the value
of the flood is far more important than the value of a small
amount of lost hydropower that might be needed to."
"Fundamentally our work comes down to
what is the best use of Zambezi waters, now what we've tried
to argue in our research from an economic, from a social from
an ecological basis is that there are fundamental tradeoffs
between water use for generating hydropower and water used
for releasing downstream floods for the benefit of people
and wildlife in the lower Zambezi - and what we've shown is
that for very small reductions in hydropower 5% or less of
the annual hydropower there can be tremendous economic social
and ecological gains downstream and infact those gains downstream
far outweigh the costs of lost hydropower so when you look
at those tradeoffs it really becomes one of a political argument
- what is more valuable to Mozambican society is it the people
on the lower Zambezi, the wildlife systems that support safari
hunting and subsistence hunting in the lower Zambezi system
or is it the electricity generation - can Mozambique afford
to reduce their energy production slightly from Cahora Bassa
in a tradeoff for all those benefits downstream that really
becomes the fundamental question. How much energy can they
afford to reduce in exchange for wildlife and for people -
and we should add that during wet years there's no tradeoff
at all, during wet years a carefully planned flood can be
released to stimulate economic production and social use of
the river, wildlife use of the floodplain and river - all
of that can be achieved in wetter years without any economic
loss in terms of hydropower and the real tradeoffs become
during the drier years - how best to manage Zambezi waters
for all those different sectors."
"As we look to the next 30-50 years the
possibility of climate change in the Zambezi basin and the
real possibility of less run off less water available in the
Zambezi basin all these tradeoffs become more and more acute
- the tradeoffs between hydropower generation and downstream
users, people fishing and farming the lower floodplain there's
less water for everyone and Mozambique and really all of the
basin countries in the Zambezi basin are going to have to
make very serious decisions about what is the best use of
Z waters, how much water is there for people in the Zambezi
versus how much water for generating hydroelectric power for
the national economy - it's those tradeoffs that are gonna
become more and more acute."
"One of the great challenges of dealing
with an enormous basin like the Zambezi is there are so many
different stakeholders and in a sense we all speak a different
language - hydrologists, social scientists, economists, political
decision makers that are interested in hydropower and engineering
aspects of the dam - we're all coming to the table with our
own individual interests and needs - people are looking at
how waters affect their fishery or how they affect their floodplain
agriculture, the dam managers are concerned with whether the
dam might overtop during a very wet year or how they can manage
the reservoir to have the right amount of water to meet hydropower
needs - but getting all these different voices at the table
and even finding common ground is really a fundamental challenge
in all of this - getting people on the same page, sort of
talking about the same needs and interests.
"Over the millennia each year the annual
floods came down the Zambezi and spilled overbank, inundating
the plains of the Zambezi all the way down into the great
Zambezi delta region and those floods each year stimulated
subsistence fisheries and farming activity, livestock grazing
activity as well as feeding the floodplains and sustaining
these massive herds of buffalo and other species that lived
out on the floodplain - now with the construction of dams
on the Zambezi those floods have been lost and what we're
really striving to do is simulate or recreate those natural
floods in the Zambezi - carefully planned and carefully timed
flood releases from Cahora Bassa dam during the normal time
when historic floods occurred during the period between January
and March each year.
"So what we're hoping is that a small
flood can be released downstream from the dam with adequate
warning systems for people so that they know when it's coming
and then they can make use of those floodwaters to plant their
crops to revitalise their subsistence fisheries those floodwaters
can come down and once again stimulate activity in the lower
Zambezi."
"So during the course of our work here
we've conducted more than 500 hours of interviews with people
all along the lower Zambezi and one thing you often hear from
fishermen along the riverbank and all the way down to the
delta is the perception that Cahora Bassa is actually blocking
fish from moving downstream - what the people are actually
seeing is the steady decrease in fish - both the size of fish
and the amount of fish they are able to catch each year -
now the real reason for that decline is the loss of spawning
grounds the loss of movement of fish out into the floodplain
where they can reproduce as well as the change in the flooding
regime where its much more difficult to catch fish than it
was in the past because they don’t get the low dry season
flows where they used to go out an simply catch fish in baskets
as they were trapped in small pools of water so they're experiencing
a reduction in both the size and the catch of fish - and they
often correctly attribute that to the dam although the actual
mechanism by which the fish are decreasing is a bit different
than the perception but the loss is real in the system."
"As we go down along the river here you
can really see all along the small machumbas these small garden
plots and agricultural areas all along the river where people
are trying to get their subsistence crops and when floods
come down at the wrong time of year they just wash these crops
right out and people complain about it from just below the
dam all the way down towards Marromeu for hundreds and hundreds
of kilometres that when the big size floods come down they
can just destroy these crops and its quite a serious problem
for some people its small family garden plots for others its
their main subsistence their main way of economic survival."
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