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 in- creasing 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 mana- gement 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 re- sources 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 con- ditions? 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 Vavarirai Choga Director Director National Directorate of Water, Mozambique Department of Water Resources, Zimbabwe Manuel Fobra Thomas Murinye Director, ARA-Centro, Mozambique 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 direc- tion 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 eas- terly 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 Zim- babwe are the Honde on the right bank and the Nya- zengu, Chiteme, Nyamhingura, Nyawamba, Nyamu- kombe, 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 at an elevation of 1,863 m amsl. The Mucambezi the lake, the terrain is very flat, with the flood plain a south-easterly direction into Mozambique. It flows system rises south of the shallow divide separating ecosystem very sensitive to changes in the flow through mixed farmlands, traversing along the south- the Pungwe and Zambezi sub-systems. Both tributa- regime. ern border of the Gorongosa National Park (GNP), ries flow southwards into the seasonal Urema Lake, where it enters the floodplain, and thence into the which exits into Urema River and thence into the main The waters of the lake and downstream Urema River Pungwe Estuary (intertidal zone). It then flows into Pungwe stem. are generally referred to as ‘white waters’ due to their the Indian Ocean at Beira Port. distinctive yellow-ochre colour and opaqueness that The physiography and drainage pattern of the basin perpetuates downstream below the confluence with The main tributaries of the Pungwe in Mozambique is illustrated in the 3-dimensional map below. On the the main Pungwe River. are the Nhazonia, the Txatora, the Vunduzi and the opposite page a figure shows the principal tributaries Urema rivers rising from the north to join the main river of the Pungwe River in Mozambique in relation to the The lower basin is just a few metres above sea level on its left bank, and the Honde, the Metuchira and the GNP and the Gorongosa Mountain. and is often subjected to flooding during the rainy Muda from the south. The Urema system is fed from season. During low river flows sea water flows back the Vanduzi River (locally known as Vunduzi) in the Urema Lake varies considerably in size from a into the river, reaching up to about 80 to 100 km from north-west and the Mucambezi River in the north-east. minimum of about 10 km2 during the dry season to the mouth. The former originates from the Gorongosa Mountain 120 km2 during periods of high river flow. Around Climate and General Hydrology The major influences on climate in the Pungwe River Basin are the altitude and orography (relief), in com- bination 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 low- lying 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.