Government of the Republic of Mozambique
Government of the Republic of Zimbabwe
A monograph of the
PUNGWE RIVER BASIN
- LIGHT EDITION
A part of the project:
DEVELOPMENT OF THE PUNGWE RIVER BASIN JOINT
INTEGRATED WATER RESOURCES MANAGEMENT STRATEGY
Preamble
Water is fundamental for human survival, health and dignity and the prerequisite for human development. However, in many places of the world the freshwater resources are under increasing pressure because of over utilisation and pollution from human activities. The Pungwe River is no exception. Although the current situation is generally good, projections of future
water requirements show an increasing competition between different water users. In addition the current problem of informal small-scale mining that periodically creates high suspended
sediment in the river has shown that the Pungwe River and its downstream users are vulnerable for manmade activities in the upper reaches.
Management of the water resources are therefore essential to overcome current and future problems of supplying water of adequate quantity and quality to all users in the Pungwe River
basin. This management must take into account the interests of all parties and sectors, including ecological factors, to enable a sustainable and equitable use of the water at the basin or
catchment scale. This is known today as Integrated Water Resources Management, or in short IWRM. IWRM is a participatory planning process, based on sound science, which brings
together stakeholders to determine how to meet society’s long-term needs for water resources while maintaining essential ecological and economic values. It is an interdisciplinary and
collected process that promotes a cross-sectoral coordination in water management.
The Pungwe River is shared by the countries Zimbabwe and Mozambique. The Governments of Zimbabwe and Mozambique have recognised the need for sustainable water management of the river and have therefore jointly emerged on the project: Pungwe River Basin Joint Integrated Water Resources Management Strategy (the Pungwe Project in short). The
Pungwe Project is a co-operative effort by the two Governments to create a framework for the sustainable and equitable management, development and conservation of the water resources of the Pungwe River basin, with the objective of increasing the derived social and economic benefits for the people living in the basin. A key element in the development of this
strategy by the Project lies in building capacity for its implementation and upgrading, to facilitate effective participatory management by both the authorities and stakeholders.
The Pungwe Project is financed by the Swedish International Development Co-operation Agency (Sida), through an agreement with Zimbabwe and Mozambique. It is implemented under
the auspices of the Department of Water Resources (DWR), in the Ministry of Rural Resources, Water Development and Irrigation (MRRWD&I), Zimbabwe, and the National Directorate
of Water (DNA), in the Ministry of Public Works and Housing, Mozambique, on behalf of the two governments. The implementing agencies are the Zimbabwe National Water Authority
(ZINWA) through the Save Catchment Manager’s Office, and the Regional Water Administration of Central Mozambique (ARA-Centro), respectively. The Pungwe project commenced
in February 2002 and is anticipated to be finalised in April 2006. A consortium of Consultants, led by SWECO International of Sweden, assists the implementing agencies during the
project.
One of the basic fundaments of IWRM is the knowledge of the current situation in the river basin. How much water resources are naturally available? What are the socio-economic conditions? How large are the potential for agricultural development in relation to soil suitability and water availability? What are the key environmental assets and how are these affected by
future development? The answers to these and many other similar questions are fundamental for a successful implementation of water management. One of the key tasks of the Pungwe
Project has therefore been to produce a “monograph”, describing in detail the Pungwe River basin in relation to water management. The final result of this task is an extensive report
series with a main report and twelve annexes, to be used as a tool for the professionals working with water management in the Pungwe River basin.
To enable a wider knowledge among the stakeholders of the Pungwe River basin the two Governments have suggested creating a short version of the monograph. Through this shorter
version the water authorities of the two countries aim to increase the awareness and understanding about the factors affecting the water resources of the Pungwe River basin and by this
promote the process of water management among the stakeholders. We hope that this River Basin Monograph will give the reader an enjoyable and informative experience.
November 2006
Julião Alferes
Director
National Directorate of Water, Mozambique
Vavarirai Choga
Director
Department of Water Resources, Zimbabwe
Manuel Fobra Director, ARA-Centro, Mozambique
Thomas Murinye
Catchment Manager, ZINWA Save, Zimbabwe
Rikard Lidén
Project Director, SWECO International, Sweden
A MONOGRAPH OF THE PUNGWE RIVER BASIN
Table of Contents
The Biophysical Environment
2
Socio-economic Conditions of the Pungwe River Basin
10
Water Resources of the Pungwe River Basin
14
Water Quality in the Pungwe River Basin
18
Water Use in the Pungwe River Basin
20
Water Resources Management in the Pungwe River Basin
22
Future Water Resources Development
24
Beira Harbour in the Pungwe Estuary
THE BIOPHYSICAL ENVIRONMENT
Physiography and Drainage
The Pungwe Basin in Zimbabwe and Mozambique
covers a total area of 31,151 km2, of which 1,461 km2
(4.7%) lies in Zimbabwe, and 29,690 km2 (95.3%) is
in Mozambique. The main Pungwe River has a total
length of approximately 400 km. The map on the
opposite page shows the basin area.
The Pungwe River originates in the eastern highlands
of Zimbabwe, and flows in a general easterly direction through Mozambique into the Indian Ocean.
The Pungwe River rises from the western slopes of
the Inyangani Mountains from an altitude of 2,500 m
above mean sea level (amsl).
It flows southwards for about 20 km, where it abruptly
changes course at Pungwe Falls, a location renowned
for its scenic beauty, and meanders in a general easterly direction through an area known as the Honde
Valley. The river then crosses the Mozambican border
near Katiyo Tea Estate, approximately 60 km from its
headwaters, at an altitude of about 579 m amsl.
The principal tributaries of the Pungwe River in Zimbabwe are the Honde on the right bank and the Nyazengu, Chiteme, Nyamhingura, Nyawamba, Nyamukombe, and Rwera rivers on the left bank.
In Zimbabwe, the drainage area is a combination
of national park area, exotic forest plantations in
the upstream reaches, and mixed agriculture in the
middle and lower valleys. The Nyamukwarara River,
a tributary of the Honde, drains some alluvial gold
mining and panning areas in both Zimbabwe and
Mozambique, where it collects a large quantity of
sediment that remains visible along the river beyond
Tete Bridge in Mozambique.
2
3
THE BIOPHYSICAL ENVIRONMENT
After crossing Zimbabwe, the Pungwe River flows in
a south-easterly direction into Mozambique. It flows
through mixed farmlands, traversing along the southern border of the Gorongosa National Park (GNP),
where it enters the floodplain, and thence into the
Pungwe Estuary (intertidal zone). It then flows into
the Indian Ocean at Beira Port.
The main tributaries of the Pungwe in Mozambique
are the Nhazonia, the Txatora, the Vunduzi and the
Urema rivers rising from the north to join the main river
on its left bank, and the Honde, the Metuchira and the
Muda from the south. The Urema system is fed from
the Vanduzi River (locally known as Vunduzi) in the
north-west and the Mucambezi River in the north-east.
The former originates from the Gorongosa Mountain
at an elevation of 1,863 m amsl. The Mucambezi
system rises south of the shallow divide separating
the Pungwe and Zambezi sub-systems. Both tributaries flow southwards into the seasonal Urema Lake,
which exits into Urema River and thence into the main
Pungwe stem.
The physiography and drainage pattern of the basin
is illustrated in the 3-dimensional map below. On the
opposite page a figure shows the principal tributaries
of the Pungwe River in Mozambique in relation to the
GNP and the Gorongosa Mountain.
Urema Lake varies considerably in size from a
minimum of about 10 km2 during the dry season to
120 km2 during periods of high river flow. Around
the lake, the terrain is very flat, with the flood plain
ecosystem very sensitive to changes in the flow
regime.
The waters of the lake and downstream Urema River
are generally referred to as ‘white waters’ due to their
distinctive yellow-ochre colour and opaqueness that
perpetuates downstream below the confluence with
the main Pungwe River.
The lower basin is just a few metres above sea level
and is often subjected to flooding during the rainy
season. During low river flows sea water flows back
into the river, reaching up to about 80 to 100 km from
the mouth.
Climate and General Hydrology
The major influences on climate in the Pungwe River
Basin are the altitude and orography (relief), in combination with proximity to the ocean. It ranges from
tropical continental in the west to tropical humid in
the coastal areas in the east. From the Mozambican
channel the general relief is characterised by lowlying land, which rises rapidly as it approaches the
eastern slopes of the Inyangani range. Orographic
influences are more pronounced in the western part
of the basin, where altitudes increase from 600 m to
over 2,500 m amsl, over a relatively short distance.
This orographic pattern forces oceanic air, when it
prevails, to rise up the eastern slopes, cooling in the
process, and if sufficiently moist, resulting in cloud
formation and often precipitation. The cloud formation also lowers surface temperature by blocking the
sun’s rays.
The physiography and drainage pattern of the Pungwe River Basin
4
Across the basin, average minimum temperatures range from 22oC in the coastal areas to 9.9oC
in the higher areas of Inyangani Mountain range,
with maxima ranging from 29oC to 19.8oC as alti-
tude increases. In the higher altitudes all year round
temperatures are among the lowest in Zimbabwe.
These low temperatures have a moderating effect
on evapotranspiration in the region, compared to
other parts of the country.
Convergence Zone (ITCZ), and the South East Trades.
The effect of orograghy on rainfall is more pronounced in the upper reaches of the basin where there
is a rapid increase in altitude, as shown in the 3D
model below to the right. Orographic effects on rainfall are also clearly illustrated by the drastic change
in specific runoff between gauging stations located
on different altitudes.
1.
The South East trades from the Indian Ocean covering Mozambique and Zimbabwe
2.
The South West Trades of the Atlantic
Ocean approaching Zimbabwe from the North West and commonly referred to as Zaire Air
A similar effect is also experienced in the Gorongosa
Mountain, in Mozambique, which receives significantly
more rainfall compared to the surrounding areas.
3.
The North East monsoon flowing out of the Asiatic High in the region of the Arabic sea
In general, the main rainfall influences in the Pungwe
catchment area are the movements of the Inter-tropical
The influence of the ITCZ normally extends from around
November to March. The ITCZ is a complex zone where
the following three distinct air currents converge:
Eastern Highlands in Zimbabwe
The principal tributaries of the Pungwe River in relation to the GNP and the Gorongosa Mountain
The South East trades are responsible for winter rainfall
falling between April and September in the higher areas
of the basin. In the Nyanga region, winter rainfall constitutes approximately 12% of annual rainfall in the area.
1220
Zimbabwe
1600
2730
2100
e
Mozambiqu
2010
2290
1330
1490
Rainfall in the upper Pungwe [mm/year]
5
THE BIOPHYSICAL ENVIRONMENT
Geology and Soils
In the western parts, the geology of the Pungwe River
Basin is dominated by extensive deeply incised granites with occasional dyke intrusives. This geological characteristic has given rise to the formation of
high mountain peaks (Inyangani Mt), deep gorges
(Pungwe Gorge) and valleys, as well as rapids and
falls (Pungwe Falls) in the vicinity of the dykes. Occasional gneissic rock is observed in the geology of
the Honde River drainage area. In the central part
of the Basin, in Mozambique, geology is dominated
by the basement complex consisting of mountains
(Gorongosa Mt), upland and middle plateau. Towards
the east geology gives way to mainly sandstones in
the Sena Plains and Cheringoma Plateau that are
divided by a continuation of the East African Rift Valley system.
The western part of the basin consists of red soils
of considerable depth in some areas, which become
shallower in the mountain areas. Towards the east,
soils below the plateau range from clayey-sandy fluvial dark soils to shallow soils with little agricultural
potential.
Flora
The figure on the opposite page shows the distribution of
16 broad vegetation types of the Pungwe River Basin.
The dominant type of vegetation, that occupies
approximately 50% of the basin, is the miombo
woodland. A total of five different species of miombo
woodland occur in the basin, depending on altitude
and rainfall.
Two important vegetation relics of moist evergreen forests
occur on the Gorongosa Mountain, and on the slopes
and gullies of the Inyangani Mountain range, along the
border between Mozambique and Zimbabwe. These unique ecosystems have been created by micro-climates
that occur in the high altitude, high rainfall areas.
In the Zimbabwean part of the Pungwe River Basin the
massive granite weathers to bare domes
Around the Urema Lake and the flood plains, vast
areas are flooded during the wet season giving rise
to floating pastures and conspicuous flowering water
lilies. This lush and verdant growth gives way to a
contrasting layer of brown shriveled grass in the dry
season.
Towards the coast, in the flood plain, mangrove communities occur on inter-riverine islands and mudflats
of the Pungwe-Buzi Estuary.
In the eastern highlands of Zimbabwe, approximately 53 km2 is covered with alien Black Wattle and
Mexican Pine, including smaller areas of Australian
Blackwood. These commercially grown species are
a threat to the natural ecosystem in the upland areas
through invasion by wind-borne seeds and subsequent suppression of the indigenous species.
Gorongosa Mountain
6
Specially protected species likely to be encountered
in the Pungwe River Basin include:
•
Fire lily, on the edge of the escarpment from Mount Inyangani, south of Mtarazi Falls
•
Flame lily, at the forest margin among bracken and woodland on the highveld
•
Tree ferns, in and around the Pungwe Gorge
•
Orchids, within miombo woodlands and forests, especially along rivers, vleis, bogs and montane grasslands
•
Cycads, in the Nyanga and Gorongosa national parks
7
THE BIOPHYSICAL ENVIRONMENT
Fauna
In the Pungwe River Basin, significant occurrence
of large mammals is mainly confined to the protected areas of Gorongosa and Nyanga national parks.
In the GNP, Tinley has described the “spectacularly
rich wildlife of the Rift Valley” as being ”a consequence of the mosaic evolution of forest thicket and
savannah, abutted against a floodplain grassland
ecosystem of high primary productivity on base
saturated soils”. This wildlife, comprising most of the
major large tropical mammals was almost decimated during the civil war of Mozambique. Efforts are
underway to restore this regionally important wildlife
sanctuary to its previous glory. These may, however, be under a new threat from current proliferating
human settlements.
The seasonally inundated Gorongosa Tandos that links Zambezi Valley in the north with the Pungwe system in the south through the Urema Trough (Rift Valley)
•
The seasonally inundated grasslands of the lower Pungwe/Buzi flood plains comprising approximately 4,500 km2 of wetland
•
The estuarine mangroves
•
The rain forest at the Pungwe Falls (pictured to the right)
The above provide crucial habitats for a variety of
fauna, some of which are endemic and/or threatened.
Protected conservation areas include the 5,370 km2
Gorongosa National Park in Mozambique, created in
1960, and the 330 km2 Nyanga National Park in the
eastern highlands of Zimbabwe.
The Beira killifish
There are some rare and vulnerable fish species in
the Pungwe River, particularly in the upper reaches
of the river. These cold water species dominate the
upper sections of the river, where the water is of
low conductivity. Warm water and marine species
become more common in the lower reaches, e.g. the
endemic Beira killifish, pictured above.
Vegetation types of conservation concerns
Vegetation types of conservation concern that are
directly reliant on water are:
8
•
The Pungwe Falls in the Nyanga National Park
9
SOCIO-ECONOMIC CONDITIONS OF THE PUNGWE RIVER BASIN
Settlements
Population
The Pungwe River is a shared watercourse between
Zimbabwe and Mozambique. Consequently, the manner in which water resources are utilised, and landuse is
managed in the upstream riparian state (Zimbabwe) have
an impact on the downstream state (Mozambique).
As at year 2003, the Pungwe River Basin had an estimated total population of 1,199,567 persons, of which
8% resided in Zimbabwe. It is estimated that by year
2023, the total population in the basin will have reached
some two million persons.
Administratively, the basin covers Mutasa Rural
District, Nyanga National Park, and a small part of
Nyanga Rural District in Zimbabwe. In Mozambique,
it straddles parts of Sofala and Manica provinces.
The overall population density in the basin is higher
in Zimbabwe compared to Mozambique. However,
in the latter part of the basin, populations become
denser in hinterland areas around towns and admi-
In general, settlements in the Pungwe River Basin
consist of rural village communities, a few scattered
small urban centres, growth points and commercial
farms and estates. These are concentrated along the
river valleys, in the flood plains, along main roads,
and around administrative centres. The City of Beira
in Mozambique is the main urban and industrial centre in the basin. The largest administrative and commercial centre in the basin in Zimbabwe is Hauna
Growth Point. Other towns of importance in the basin
in Mozambique are Chimoio on the catchment boundary, Gondola, Nhamatanda and Gorongosa.
Settlements in Honde Valley
10
nistrative centres, as well as along main roads. The
population distribution in the basin, divided into subbasins, is shown in the figure below.
Economic Activities
Economic activities among basin communities are
largely agro-based. They include crop and livestock
production, forestry, fisheries, gold mining and ecotourism. Agriculture is a mixture of subsistence dry
land and irrigated crop farming.
Shrimps caught in the Pungwe Estuary
rests comprising the Gorongosa National Park (GNP),
a large sugar cane irrigation estate, Beira/Dondo City
water supply, and prawn farming and fishing around the
estuary. In the floodplain, below the Bue Maria dam site,
there is a huge potential for agricultural development
due to the occurrence of fertile soils and the possibility
of a major dam on the Pungwe River. In addition, the
ongoing rehabilitation of eco-tourism in GNP and adjoining areas has the potential to create favourable conditions for economic development in the basin.
Tobacco plantations
Small-scale farming
The major problems concerning health management
in Mozambique are related to:
The upper part of the basin that lies in Zimbabwe supports intensive agriculture in the densely populated
Mutasa Communal Lands and large-scale commercial
coffee, tea and forest plantations. The southern portion
of the Nyanga National Park, an important tourist location, is drained by the headwaters of the Pungwe River.
The City of Mutare abstracts raw water from the river
just upstream of the scenic Pungwe Falls.
The middle section of the Pungwe River Basin in
Mozambique has hitherto been largely underdeveloped
and sparsely populated, with a potential for irrigation
agriculture, tourism and wildlife development. In recent
years there has been a steady increase in investments
in large-scale commercial farming of important crops
such as maize, tobacco and horticulture products, particularly in the Manica Province.
In the lower part of the basin, the floodplain, there
are major natural resource, economic and social inte-
•
poor coverage and, consequently, limited access to quality services
•
access to clean water and adequate sanitation
•
lack of education on disease prevention
•
low literacy levels
•
underdeveloped poverty alleviation strategies
Sanitation facilities in the basin are still generally basic,
and largely based on pit latrine or the use of the open
bush. Coverage is variable, with more facilities in Zimbabwe compared to Mozambique.
Health and Sanitation
The status of health facilities in the basin is generally poor, particularly in Mozambique. In Zimbabwe,
which is endowed with better infrastructure, services
are deteriorating due to diminishing resources.
The HIV/AIDS pandemic is exerting considerable pressure on an already stressed health delivery system in
the basin. It is estimated that about 20% of the population in the basin are HIV positive, and that by 2010,
the projected life expectancy will be reduced to 36.5
years of age.
11
SOCIO-ECONOMIC CONDITIONS OF THE PUNGWE RIVER BASIN
Education
Infrastructure
The education status in the basin is variable. Whereas in
Mozambique most pupils that complete Level 1 primary
school do not proceed to higher grades, in Zimbabwe,
the majority of pupils in the education system proceed
to secondary school. Remote areas in Mozambique are
particularly poorly served, with the few existing secondary schools located in the district capitals.
Water Supply, Dams
In Mozambique, the critical shortage of qualified
teaching staff compounds the problem. The education network is, however, steadily developing. The
Ministry of Education is implementing short training
courses to upgrade teachers in co-operation with
partners such as UNICEF and GTZ.
There are no large dams in the Pungwe River Basin
in Mozambique with the exception of 19 small dams
used for crop irrigation.
Gender and Poverty
Poverty in the basin continues to be a major setback to
sustainable development, despite abundant water and
other natural resources. This is exacerbated by entrenched inequalities in the distribution and control of natural resources such as land and water in favour of men.
In Zimbabwe, women have representation in the
decision-making bodies such as catchment and
subcatchment councils. The water sector in Mozambique also recommended that women be included
in water committees. It is hoped that these progressive administrative arrangements will be backed by
the necessary political will to promote the participation of women in water affairs, and development
in general.
With regard to poverty, the majority of rural households in the Pungwe River Basin have incomes that
fall below a level that satisfies basic needs.
12
The Pungwe River Basin in Zimbabwe has only one
large dam on the Nyawamba River, with a capacity of
17 million m3, and a small 40,000 m3 impoundment
on the Nyamasupa River. Nyawamba Dam is owned
and operated by the Eastern Highlands Tea Estate.
Major Water Supply Schemes
Major water supply schemes located on the Pungwe River
include the Pungwe Mutare Water Supply Project, and the
Mafambise Sugar Estate/Beira Water Supply System.
Other Water Supply Schemes
Other water supply schemes comprise small piped
water supply schemes on tributaries of the Pungwe
River in Zimbabwe, and several small irrigation schemes in both countries.
Sanitation
Sanitation facilities in the catchment are largely based
on pit latrines for rural villages, with the exception of
Hauna and Beira City where water-based systems
have been developed.
Energy
The Pungwe River Basin is supplied with electricity
from the national grids of Zimbabwe and Mozambique.
Roads and Railways
The major centres in the basin are generally serviced
with a good network of tarred national roads. These are
well maintained by the national authorities. However, road
communication in the remote areas is very poor, and consists of largely unserviced gravel roads and tracks.
Although the secondary road network in Zimbabwe is
better, most villages are not serviced due to the mountainous terrain that complicates road construction.
The Port of Beira is linked to Mutare by a railway line.
Water intake for the Beira water supply
However, traffic along the line has been greatly reduced in recent years, probably due to the combination
of the residual effects of the civil war in Mozambique,
and the current decline in the economy of Zimbabwe.
Telecommunications
Mostly the major centres, and some large-scale commercial farms and schools are served with fixed telephone services. Both Mozambique and Zimbabwe
have mobile telephone services. However, coverage
is also limited to the major centres and along some
sections of the primary road network.
Bridge crossing the Nyamukwarara River in Mozambique, secondary road
However, distribution is limited to the major urban and
administrative centres, and some large-scale commercial farms and plantations.
The majority of the rural communities are not connected to electricity, and rely on wood fuel for domestic
energy. Deforestation, and the risk of soil erosion are
therefore a serious threat to the natural environment
and the associated wildlife habitats.
Deforestation close to the Gorongosa Bridge
The Gorongosa Bridge, national road
13
WATER RESOURCES OF THE PUNGWE RIVER BASIN
Measurement and Monitoring
The assessment or quantification of water resources
requires the measurement of rainfall, evaporation and
stream flow on a continuous basis. Pursuant to this
requirement, meteorological and water management
authorities in Mozambique and Zimbabwe operate
networks of gauges for the measurement of these hydrological parameters. The distribution of these stations, existing and historical, are shown in the figure
to the right.
In general, available rainfall records have been collected for longer periods than river flow records. The
measurement of rainfall is also more simplified such
that its data is usually readily available in sufficient
time length and spatial distribution.
Rainfall Stations
In the basin, Mozambique and Zimbabwe respectively have rainfall data from 77 and 18 identified stations. Three of the stations in Zimbabwe and six in
Mozambique are described as synoptic because they
include the measurement of evaporation data and
other weather parameters such as barometric pressure, temperature and humidity.
Ideally, the distribution of rainfall stations in a catchment should be as uniform as possible, and take
into account variations in relief. However, in the
basin, this requirement is constrained by the poor
road network coupled with the uneven distribution
of settlements, particularly in Mozambique. Furthermore, a significant proportion of rainfall data in the
catchment has missing data, and of questionable
accuracy.
14
Flow Gauging Stations
Flow gauging provides a direct measure of the surface water resources of the catchment. River flows are
normally measured on a daily or continuous basis,
manually or by means of an automatic stage recorder. The parameter measured in the field is the depth,
which is then transformed into stream flow by means
of a previously developed rating curve.
In the Pungwe Basin, flow data is available from 22
stations in Mozambique, and four in Zimbabwe. The
lengths of these flow records range from 1953 to current. Nearly all the data series from the gauging stations contain gaps, usually where flow measurements
were not made for various reasons.
Before use in the assessment of water resources,
historical flow records are first screened and then
repaired or extended through mathematical relations
(models) with gauged rainfall.
Rainfall in the Pungwe River Basin
Water resources in a river basin, in particular surface
water, are a function of rainfall. Higher rainfall translates into high unit runoff into rivers. The effect of rainfall
on groundwater depends on the relative distribution
of recharge areas, the geology of the area, and the
nature of groundwater movements.
Mean annual precipitation in the basin ranges from above
2,020 mm in the high elevation areas of Inyangani Mountain range, in Zimbabwe, to about 1,180 mm in the Pungwe
Estuary. The figure below shows the mean annual rainfall
for the Pungwe River Basin, divided into sub-basins.
Potential evaporation lies between 1,380 to 1,590 mm,
depending on temperature and relative humidity.
Flow gauging station F14 in Zimbabwe
Scale for measuring water depth
at the E65 station in Mozambique
Flow gauging station F22 in Zimbabwe
15
WATER RESOURCES OF THE PUNGWE RIVER BASIN
Surface Water Resources
The table shows the relative contributions to long-term
runoff of the basin areas in Zimbabwe and Mozambique.
The long-term water resources of the Pungwe River Basin have been determined for the various sub-basins,
and at selected locations along the main river.
Mean annual runoff in mm/yr by sub-basin is shown
in the figure to the right. The effect of rainfall on unit
runoff is clearly indicated.
Point
Area
2
Zimbabwe
Mozambique
TOTAL
Natural MAR
3
Percentage
[km ]
[million m /year]
[mm/year]
of total
1 463
29 687
31 150
1 191
3 004
4 195
814
101
135
28%
72%
-
Based on data from the period 1960-80
16
Natural MAR
TOTAL OUTFLOW TO THE INDIAN OCEAN
1800
Exceedance of 20% (Wet year)
Exceedance of 50% (Medium year)
1600
Although Zimbabwe is only about 5% of the total basin
area, it accounts for 28% of the total runoff. Water use
in Zimbabwe is therefore likely to have a major impact
on water resources in Mozambique.
The graph to the right shows the mean monthly distribution
of stream flow at the Pungwe River mouth. On average,
the highest flows occur around the month of February.
Average flow (Mm3/month)
The main source of water in the Pungwe River Basin
is surface water. A sound understanding of the longterm surface water resources of the basin is essential
for the sustainable development of the basin.
2000
Exceedance of 75% (Dry year)
1400
1200
1000
800
600
400
200
0
oct
nov
dec
jan
feb
mar
apr
may
jun
jul
aug
sep
Groundwater
Pictures of the flood in 1999 at the Pungwe Bridge in Mozambique
Large areas of the Pungwe River Basin have moderate to low groundwater potential, with the exception
of small parts of the Upper Pungwe where the potential can be considered to be high.
It is expected that zones along rivers are likely to
have high yields of groundwater, depending on the
prevailing geology.
Floods
Floods frequently cause problems in the lower parts
of the Pungwe River Basin. During the years spanning the period 1999-2001, very high water levels occurred in the Pungwe River causing severe damage
to riparian settlements and infrastructure, including
the national road between Beira and Chimoio. The
flood of 2001 is the highest observed flood at the
Pungwe Bridge flow gauging station since the commencement of observations in the 1950s.
Groundwater well in Mozambique
The main feature of the floods in the lower basin is
the very long duration of sustained high water levels.
During the 1999 and 2001 floods, high water levels
persisted for periods of between 2 to 3 months at
a time. These severe floods are difficult to mitigate,
though it is possible to mitigate more moderate floods
through the construction of dams at strategic locations along the river.
Notwithstanding their destructive effect on riparian
settlements and infrastructure, floods events are important for the rejuvenation of the ecology of the river system, through their capacity to transport and
deposit nutrients on which floodplain cultivation and
estuarine fauna depend.
17
WATER QUALITY IN THE PUNGWE RIVER BASIN
Sources of Water Pollution
The water quality of the basin is affected by human
settlements, the geology and soil, and vegetation. Human settlements invariably alter the natural state of
the quality of both surface and groundwater through
the different uses of land, and water use for domestic,
mining, industrial, and agricultural purposes.
The main sources of water pollution in the Pungwe River Basin are rural and urban settlements, agriculture,
afforestation, gold panning and salt water intrusion.
Although the latter is a natural phenomenon, it can
be exacerbated by high abstraction of water from the
river during the low flow season.
With the exception of alluvial gold mining in the Nyamukwarara River, most of the potential sources of
pollution are not considered to be serious at present.
Large quantities of sediment are routinely released
into the Nyamukwarara River as a result gold panning
activities.
Ambient Water Quality
Water quality in the upper reaches of the Pungwe
River in Zimbabwe is almost pristine because of
the existence of Nyanga National Parks where human settlements are forbidden by law. For the rest
of the catchment, land-use and sanitation practice
play a major role in determining the water quality in
the basin’s rivers. The rural character of the basin’s
settlements has a significant influence on the nature
of the ambient water quality. Both point and diffuse
water pollution can be expected in the basin, from
large-scale commercial and communal subsistence
agriculture, as well as the general sanitation practice
in the basin.
18
Informal gold mining activities in the Nyamukwarara River
Artisanal Gold Mining
Gold mining has been practiced in the Pungwe River
Basin for several centuries. Observations since 2003
have shown a drastic increase in sediment concentrations in the river due to the proliferation of informal
gold mining activities. Previously, mining operations
were confined to the Nyamukwarara River and its
surrounding areas, in Manica Province. However, in
recent times, the practice has now spread to other
areas in the Pungwe River Basin, as far downstream
as Muda River, in Sofala Province.
Excavation for gold mining loosens the soil, leading
to its erosion during the rainy season. The operation
also strips the protective vegetation cover, thus creating conditions for further erosion and degradation of
arable land, well after the mining site has been abandoned.
The eroded soil from the mining activities is deposited in the Pungwe River system as sediment, which
consists mainly of reddish-brown silt and clay, with a
negligible proportion of sand. The fine sized sediment
particles remain in suspension, exhibiting a red (ochre) colour that is evident all the way to the Pungwe
Estuary.
The Pungwe River in the Nyanga National Park in Zimbabwe
The Pungwe River at the Tete Road Bridge in Mozambique
The suspended sediments render the water unsuitable for drinking, washing and irrigation. They block
the penetration of light into the water, thus reducing
the efficiency of photosynthesis. Fish species that are
sensitive to sediment-laden waters are also affected.
Salt Water Intrusion
The tidal variations in the ocean at the Pungwe Estuary are considerable being in the order of 7-8 m. The
water intake of the Mafambisse pumping plant located about 90 km upstream, currently also used for the
Beira Water Supply, is therefore affected from time
to time. The salinity intrusion has forced Aguas de
Moçambique to relocate the Beira Water Supply intake some 40 km upstream. The problem of saline
water for the pumping plant serving Mafambisse Sugar Estate however remains and causes interruptions
in the irrigation practises.
The tidal variation involves several cycles. Besides
the daily cycle with two spring tides per day the
magnitude varies several metres in a 2-week cycle.
Further, there is a seasonal cycle with the highest tidal differences occurring twice every year. By using
free software the tidal levels can be calculated for any
place and time. The dates with extreme tides can therefore be easily predicted.
Salt water intrusion in the Pungwe River, caused by the tidal variations of the Indian Ocean at Beira
19
WATER USE IN THE PUNGWE RIVER BASIN
Uses of Water in the Pungwe River Basin
The uses of water in the basin reflect its socio-economic conditions and existing water developments. The
main consumers of water from the Pungwe River and
its tributaries are as follows:
•
rural domestic consumers through piped schemes and undeveloped abstraction facilities
•
the urban domestic and industrial consumers of Beira/Dondo and Mutare cities
•
small and large-scale irrigators
•
forestry
Rural:
Rural water supply is in comparison with the agricultural and urban supply very small and is generally
supplied by small local groundwater schemes.
3
98 087 m /day or
3
Irrigation and forestry demand 2003:
3
Mozambique
Forestry:
7.5-10 million m /year
Zimbabwe
Mozambique
Zimbabwe
Mafambisse water intake
3
60 480 m /day
3
10 306 m /day
3
1 962 m /day
35.8 million m /year
Irrigation:
TOTAL:
Sugar cane plantations
20
Mutare
Mozambique
Zimbabwe
TOTAL:
Livestock:
The largest water user in the Pungwe River basin is
the agricultural sector. Irrigation stands in average for
more than 80% of the total use of water. The second
largest water use is urban water supply to Beira and
Mutare. Although, Mutare is outside the Pungwe River
Basin it receives its water by inter-catchment transfer
through the Pungwe-Mutare tunnel and pipeline.
Water supply demand 2003:
3
Beira/Dondo
Urban:
25 339 m /day
Mozambique
Zimbabwe
3
16-21 million m /year
3
0.5 million m /year
3
84-190 million m /year
3
38 million m /year
3
146-260 million m /year
Water Demand in the Pungwe River Basin
As at 2003, water demand in the basin was estimated
at 35,8 million m3 per year for domestic and industrial
use, and between 146 and 260 million m3 per year for
agricultural use, including forestry and livestock.
Future water demand depends on the general socioeconomic development in the Pungwe River Basin.
Estimates indicate that in a medium development
scenario the total water demand in the basin will increase to between 750 and 800 million m3 per year in
year 2025. It is estimated that approximately 15-25%
of this future water demand is in Zimbabwe.
Water Balance
In this context, a water balance refers to the comparison of estimated volumetric use of water with total
available resources.
Mapopo River in the upper Pungwe
A water balance analysis, taking into account the temporal variability, shows that measures are needed to
supply the Mutare urban water if the sole source should
be Pungwe. In 2025 severe water shortages will occur if a dam is not constructed upstream the present
Mutare pipeline intake or other sources are utilised.
The Beira water requirements of 2025, however will
probably be supported without further infrastructure in
the Pungwe River, provided that the water intake is not
suffering saline water intrusion.
For most of the tributaries in Pungwe River Basin
the full irrigation requirements of 2025 can be met
by the natural runoff. Local small-scale dams would
most probably give full assurance of supply in these
areas. However, in the lower part of the basin the
2025 medium requirements would originate from
large scale sugar cane, which cannot be met without
major regulating dams.
140
Zimbabwe border
120
100
80
60
40
20
0
10000
8000
7000
6000
5000
4000
3000
2000
1000
20
02
20
00
19
98
19
96
19
94
19
92
19
90
19
88
19
86
19
84
19
82
19
80
19
78
19
76
19
74
19
72
19
70
19
68
19
66
19
64
19
62
19
60
19
58
0
19
56
The variation of water resources is, however, large
both temporally and spatially. Cyclic pattern with
many wet years followed by consecutive dry years
are typical for southern Africa. Dry periods such as
the one in the early 1990s set the limits for secure
water supply even if the average flow is normally
sufficient to cover the average demand.
Beira Water intake
9000
19
54
It is evident that water resources in the basin are currently under-utilised. Considering that the long-term
total surface water resources of the Pungwe River
are estimated to about four billion m3 /year, the future
estimated water demand in 2025 comprises only one
fifth of the available resource.
The figure shows the mean annual runoff for the last 50 years (Mm3/year). The red line denotes the average annual river
flow. The large inter-annual variation in water resources in the Pungwe River Basin causes large demands on water management. Dry spells, e.g. 1991-1995, create large stress on the water users.
21
WATER RESOURCES MANAGEMENT IN THE PUNGWE RIVER BASIN
Pungwe River Basin Management
There are five shared water courses between Zimbabwe and Mozambique comprising the Pungwe,
Buzi, Sabi, Zambezi and Limpopo rivers, as shown in
the figure to the right. In all cases, Mozambique is the
downstream riparian state.
Water management in the two states is provided for
through the following national laws:
22
•
Mozambique - Water Act Lei No 16/91
•
Zimbabwe - Water Act [Chapter 20:24] No 31/98
•
Zimbabwe - Zimbabwe National Water Authority
Act [Chapter 20:25] No 11/98 Country to coun-
try (bilateral) co-operation in water manage-
ment is addressed through the following inter-
national conventions, regional protocols and related declarations
•
The United Nations Convention on the law of the non navigational uses of international water
courses, 1997
•
The revised Protocol on shared waters in the SADC, 2000
•
The Convention on the conservation of nature and natural resources, September 1997
•
The Constitutive Act of the African Union (June 2000) and NEPAD
•
The Abuja Ministerial Declaration on Water - a key to sustainable development, April 2002
National Statutes
Macheke, Budzi and Devure subcatchments.
Bi-lateral Co-operation
The Water Law of Mozambique
The Water Act provides for the appointment of a
Catchment Manager who is an employee of the Zimbabwe National Water Authority, (ZINWA).
The key instrument for bilateral co-operation on international waters in the southern African region is the
Revised Protocol on Shared Watercourses in the
SADC. Primarily, it addresses key water management
issues related to the equitable and sustainable use
of shared water resources. To achieve these noble
goals, the Protocol provides for the establishment of
watercourse commissions, also known as Joint Water
Commissions to administer interstate agreements
on water affairs, and to provide technical advice.
The Joint Water Commission (JWC) for the Pungwe
River was created in December 2002. Its core functions are to advise the principal states on measures
and arrangements to determine potentially available
water, utilisation levels, reasonable demand, relevant
data and information, criteria for conservation, allocation and sustainable utilisation, and pollution prevention of the common water resources.
The Water Act Lei No 16/91 was promulgated in 1991
based on the principle of decentralisation in water
resources management, at operational level.
It paved the way for the creation of five Regional
Water Administrations (ARAs) on the basis of contiguous river basins. ARA-Centro is responsible for the
technical and administrative management of water
resources of the Pungwe, Save and Buzi river basins.
Its mandate also includes the planning, design, construction, operation and maintenance of the hydrometeorological network, as well as hydraulic works.
The Water Law of Zimbabwe
The Water Act, Chapter 20:24 of 1998 is the umbrella
law for the management and administration of all
water affairs in Zimbabwe. It provides for the declaration of ‘river systems’ or Catchment Areas. There are
currently seven river systems in Zimbabwe whose
boundaries have been established through a Statutory Instrument No 34 of 2000, for the management
of water in Zimbabwe.
The Catchment Area is administered by Catchment
Council, an elected body of stakeholders that has
been created through Statutory Instrument 209 of
2000, to control and administer water affairs in the
catchment. Each Catchment Area is subdivided into
subcatchments, to provide for water management by
an elected subcatchment council within a more localised river subsystem.
The Pungwe Subcatchment in Zimbabwe falls inside
the jurisdiction of the Save Catchment together with
the Odzi, Upper Save, Lower Save, Lower Save West,
The Catchment Manager (CM) is responsible for the
day-today management and administration of the
affairs of the Catchment Council. For expediency, the
functions of the Catchment Council are delegated on
the CM’s office, as appropriate, in the normal course
of business. The CM performs his duties under the
direction of the Catchment Council with supervision
from ZINWA.
In terms of the Water Act, the principal functions of
the Catchment Council are as summarised below.
1.
To prepare a Catchment Outline Plan (COP) for its river system.
2.
To determine and grant water use permits.
3.
To regulate and supervise the exercise of rights to the use of water.
4.
To ensure proper compliance with the Act and to supervise subcatchment councils (SCC).
The SCC is the operational arm of the CC in the
regulation and supervision of the exercise of rights to
water within the area for which it was established.
In addition to its secretarial and advisory responsibilities, ZINWA Save Catchment Office has other core
functions related to engineering services for the provision of water supply, hydrological data collection
and analysis, as well as pollution control.
Signing ceremony for the Pungwe Project
23
FUTURE WATER RESORCES DEVELOPMENT
Water Resources Development
The development outlook of the Pungwe River Basin
depends on a number of issues, some of them not
directly in the hands of the basin population and of a
macro-political and economic dimension. However, both
countries have recently adopted policies which aim at
promotion of a sustainable development and use of the
water resources as a mean to fight poverty, and support
economic development in other sectors of society.
Agriculture is the main economic sector in the
Pungwe River Basin in both countries. The potential
for a future expansion of the agriculture activities in
the basin is extensive, however the present hydraulic infrastructure is only able to support a fraction of
the potential. Increased diversification of crops is taking place, although the dominating crops are still tea,
tobacco and sugar cane.
There are no immediate plans for larger industrial establishments in the basin partly because of the lack of supporting infrastructure. Agro-industrial developments are
slowly growing and have a potential to increase along
with growing agriculture and irrigation activities.
Urban and Rural water supply systems are in need of
major rehabilitation and expansion to meet national
goals for efficient water use and coverage levels.
Both Beira and Mutare display very high water losses
in their distribution systems.
The hydropower potential of the Pungwe River in
Mozambique should be seen as an interesting possibility in the national and regional context, as the power
system is interconnected with the Cahora Bassa
hydropower plant. Direct Power Export/Exchange
between Mozambique and Zimbabwe is another interesting possibility.
24
Flooding is frequent in the lower parts of the Pungwe
River Basin. Future irrigation and hydropower dams
on the Pungwe River may to some extent mitigate the
effects of floods in the lower basin, but there is also a
need to install flood forecasting and flood protection systems in the basin.
The impact on the river from gold mining activities in
the upper catchment is a major problem from a water
quality point of view in the Pungwe River. The impact
is currently the most apparent environmental problem
that needs urgent attention.
Gorongosa National Park would play an important
role in tourism development of the basin, attracting eco-tourism, but will require rehabilitation and
upgrading of its status. The Pungwe, Honde and
Nyamukwarara river valleys and the Nyanga National
Park in the upper catchment in Zimbabwe, with their
surrounding mountains and plateaus, form some of
the most spectacular, varied, and interesting scenery
in the whole of Southern Africa, and is a candidate for
World Heritage status.
Stakeholder Participation
Stakeholder meeting in Dondo, Mozambique
Stakeholder participation and consultation are key
elements in the development of the Pungwe River
Basin. A participatory approach is needed in order to
reach consensus for the future development and thus
safeguarding that interests and concerns of stakeholders are taken into account in the process of identification and design of projects and programmes.
In Zimbabwe, water users and other stakeholders are
organised in the Pungwe Sub-Catchment Council, a
legal body under the Water Act. In the Zimbabwean
part of the Pungwe River Basin, the Pungwe SubCatchment Council is fully operational, has its own
office in Hauna and has two paid employees. In the
Mozambique part of the Pungwe River Basin ARACentro, being a relatively new institution, has just
recently established the Pungue Basin Committee.
These stakeholder forums ensure that information on
the demands from the water users and other parties
reaches the water authorities, while information on
regulations and technical issues goes the opposite
way. Development programmes on e.g. water demand
management, rural water supply, increased reliability
of rainfed agriculture and small-scale irrigation and
legalising the informal gold miners should be initiated
through the stakeholder participation process.
The development of water resources infrastructure
will preferably involve an intensive process of stakeholder consultations, as part of the preparation of
feasibility studies and implementation activities. Two
aspects need to be distinguished. The first is the
formal consultation process that any infrastructural
development of such a magnitude will require, mostly
focused on the directly and indirectly affected parties,
such as the land users and communities that reside
in the areas affected by the dam construction and the
reservoir. The second aspect is that the development
of hydraulic infrastructure, being part of a vision for
local and regional economic development, should be
considered an opportunity to involve stakeholders in
that economic development process.
Institutional Roles and Bi-lateral Agreements
The regional water authorities in Mozambique and
Zimbabwe, ARA-Centro and ZINWA Save, will have a
key role in the joint development of water resources
of the Pungwe River Basin. They will drive the water
management in liaison with the stakeholders and
carry out the key activities of the development programmes. Also the general growth in water use will
require capacity to exercise the authority in terms of
planning, approval, and supervision.
For the future joint management of the transboundary
Pungwe River there is further a need for a comprehensive bilateral agreement between Zimbabwe and
Mozambique. Both countries have ratified the revised
Protocol on Shared Watercourses in the SADC
region and a Joint Water Commission has already
been established. An agreement based on among
others the information in this monograph is thus the
next step of implementing a joint integrated water
management of the water resources in the Pungwe
River Basin.
25
ABBREVIATIONS, ACRONYMS AND DEFINITIONS
THE PUNGWE PROJECT
ARAs
Regional water authorities of Mozambique
The Pungwe Project is financed by the Swedish International Development Cooperation Agency (Sida), through an agreement with Zimbabwe and Mozambique.
CC
Catchment Council
CM
Catchment Manager
COP
Catchment outline plan
Estuary
A section of the river near its mouth that experiences tidal activity from the sea
Fauna
Animals
Flora
Vegetations
Geology
A study of the rocks in the earth’s crust
GNP
Gorongosa National Park
Hydrology
A study of surface water resources and their temporal and spatial variation
JWC
The project receives technical assistance from a consortium of consulting companies and institutions led by SWECO International AB of Sweden. Other consortium
members are listed below.
•
CONSULTEC – Consultores Associados, Mozambique
•
IMPACTO – Projectos e Estudos de Impacto Ambiental, Mozambique
•
UCM – Catholic University of Beira, Mozambique
Joint Water Commission
•
ICZ – Interconsult Zimbabwe, Zimbabwe
MAP
Mean Annual Precipitation
•
ARCADIS Euroconsult, The Netherlands
MAR
Mean Annual Runoff
•
OPTO International AB, Sweden
Orography
Relief
•
NCG – Nordic Consulting Group of Sweden
•
SMHI – Swedish Meteorological and Hydrological Institute.
Physiography General relief and its relationship to the river system
Pungwe RiverBaseline information and data on the socio-economic and biophysical
Monograph conditions in the Basin
Rating curve The physical relationship between the surface water level of a stream and its discharge
26
The project is implemented under the auspices of the Department of Water
Resources (DWR), Zimbabwe, and the National Directorate of Water (DNA),
Mozambique, on behalf of the two governments. The implementing agencies are
the Zimbabwe National Water Authority (ZINWA) through the Save Catchment
Manager’s Office, and the Regional Water Administration of Central Mozambique
(ARA-Centro), respectively.
SCC
Subcatchment Council
Stage
The surface water level of a stream measured against some specified datum
ZINWA Zimbabwe National Water Authority
The results of the project that are partly presented in this report are a joint effort from
the Client, Funding Agency and the Consultant team listed above. All contributions to
the project from the members of the above organisations as well as external persons
and organisations are greatly acknowledged.
Information on the Pungwe Project can be obtained at www.pungweriver.net.
LITERATURE
CONTACT DETAILS
The Pungwe Project has produced the following major reports:
For further information about the Pungwe Project or the ongoing IWRM work in
the basin, please contact:
The Pungwe Monograph Report (April 2004):
Main Report
Annex I
Surface Water Resources
Annex II
Hydrometric Networks
Annex III
Hydrological Data Quality & Modelling
Annex IV
Groundwater Resources
Annex V
Dams and other Hydraulic Works
Annex VI
Water Quality and Sediment transport
Annex VII
Water Demand for Water Supply & Sanitation
Annex VIII
Water Demand for Irrigation and Forestry
Annex IX
Fisheries
Annex X
Conservation Areas, Wildlife and Tourism
Annex XI
Infrastructure
Annex XII
Socio-economy
Development Scenario Report (December 2005):
Volume I
Main Report
Volume II
Activities of the Stakeholder Component
Volume III Technical Report
Volume IV Institutional Capacity Building
ARA-Centro - Beira
Mr. Manuel Fobra, Director
tel. +258 23 324168 or 324153
fax +258 23 324163
e-mail: [email protected]
ZINWA Save - Mutare
Mr. Thomas Murinye, Catchment Manager
tel. +263 20 60926
fax +263 20 62848
e-mail: [email protected]
SWECO International
Mr. Rikard Lidén, Project Director
tel. +46 40 167281
fax +46 40 154347
e-mail: [email protected]
Sida (Asdi), Maputo
Mrs. Gunilla Ölund Wingqvist, Programme Officer, Regional Water Resources
tel. +258 21 480300
fax +258 21 480390
e-mail: [email protected]
Joint IWRM and Development Strategy Report (November 2006)
Part I
The Strategy
Part II
Justification
Part III
Annexes
27
The Pungwe River Basin Joint Integrated Water Resources Management Strategy (IWRMS) is a co-operative effort by the Governments of Zimbabwe
and Mozambique to create a framework for the sustainable and equitable management, development and conservation of the water resources of the
Pungwe River Basin, with the objective of increasing the derived social and economic benefits for the people living in the basin. The Pungwe River is a
shared watercourse between the two countries.
The Pungwe Project is financed by the Swedish International Development Co-operation Agency (Sida), through an agreement with Zimbabwe and
Mozambique. A team of consultants from Sweden, Netherlands, Mozambique and Zimbabwe, lead by SWECO International, conducts the study together
with the implementing agencies in Zimbabwe and Mozambique.
This Pungwe River monograph makes an introduction to the Pungwe River Basin and the basis for water resources management in the river basin. The
report aims to give the reader an overview of the current situation in the Pungwe River Basin regarding the legal and institutional framework for water
management, water resources, water demand, development options and environmental and socio-economic conditions.
ARA
CENTRO
CIDDI - UCM