STATE-OF-RIVERS REPORT UMNGENI RIVER AND NEIGHBOURING RIVERS AND STREAMS 2002 PRODUCT OF THE RIVER HEALTH PROGRAMME Design and production: Loretta Steyn Graphic Design Studio This report is based on the findings of river C ONTENTS 1 surveys that were conducted on the uMngeni, uMlazi, uMhlatuzana and uMbilo rivers between INTRODUCTION 2 1992 and 2002 as part of the implementation of Why know about river health? 2 The River Health Programme 3 CONTEXT the River Health Programme in KwaZulu-Natal. Measuring river health 4 River health classification 6 State-of-Rivers (SoR) reporting 7 Department of Water Affairs and Forestry UMNGENI AND NEIGHBOURING Department of Environmental Affairs and Tourism CATCHMENT ECOREGIONS 8 Water Research Commission OVERVIEW OF THE STUDY AREA 10 Umgeni Water HOW TO READ THIS REPORT 12 eThekwini Municipality MIDMAR RESOURCE UNIT 14 CSIR Environmentek ALBERT FALLS RESOURCE UNIT 16 University of Natal UPPER UMSUNDUZE RESOURCE UNIT 18 PIETERMARITZBURG RESOURCE UNIT 20 ATCPTN ORGANISATIONS PARTICIPATING INANDA RESOURCE UNIT 22 LOWER UMNGENI RESOURCE UNIT 24 UMLAZI RESOURCE UNIT 26 This report is based on data that has been accumulated SUMMARY DIAGRAM OF STATE OF RIVERS 28 by several organisations over a number of years. DAMS AND URBAN RIVERS 30 For the full list of contributors, refer to the back of this report. FISH OF THE UMNGENI RIVER 32 A HISTORICAL DESCRIPTION OF THE UMNGENI RIVER 34 CONTRIBUTORS HISTORICAL REFERENCES CONTRIBUTORS This report has been reviewed by http://www.csir.co.za/rhp/ the Water Research Commission and approved for publication. Suggested citation: Approval does not indicate that WRC 2002. State-of-Rivers Report the contents necessarily reflect uMngeni River and neighbouring the views and policies of the WRC, rivers and streams nor does mention of trade names WRC report no.TT 200/02 or commercial products constitute Water Research Commission endorsement or recommendation Pretoria DISCLAIMER for use. ISBN No: 1 86845 899 7 3 2 I NTRODUCTION THE RIVER HEALTH PROGRAMME Background Legal context of the RHP The Department of Water Affairs and Forestry (DWAF) is the The equitable, efficient and sustainable use of our water resources custodian of our country’s water resources. This responsibility is the central objective of South Africa’s water policy. The includes the protection of the ability of river ecosystems to con- National Water Act (1998) recognises that the best way to tinue to provide goods and services, and in doing so, to protect achieve this would be to manage aquatic ecosystems (including their use and associated benefits for current and future genera- rivers) at the catchment scale and through joint participation by tions. As a result, DWAF initiated the River Health Programme all interested parties. The RHP supports this management process (RHP) in 1994. by providing river health information that will be needed by both managers and the participating public to make decisions. What is the objective of the RHP? This programme is designed to develop a capacity and information base to enable us to report on Although the RHP is not specifically mandated by any South the ecological state of our rivers, in an objective and scientifically African act of parliament, RHP activities and outputs are strongly sound manner. At the same time, through river health reporting, aligned with legal requirements: The Water Act requires that the the programme aims to be explicit in identifying areas of sustain- health of aquatic ecosystems is monitored and the RHP monitor- able utilisation and also to flag areas where deterioration of the ing results can in turn, be used to support certain legal principles river system is causing undesirable changes in the delivery of contained in the National Environmental Management Act goods and services. (NEMA) and the National Water Act. For example, RHP results can be used to support evidence of environmental degradation. What does the RHP do? The programme generates information The law also requires that river protection measures should take which is based on the assessment of the condition of biological into account the characteristics of in-stream and riparian vegeta- communities in and around rivers (such as fish, aquatic inverte- tion as well as the characteristics and distribution of aquatic plants brates, riparian vegetation and river habitats). Together, they pro- and animals. WHY IS IT IMPORTANT Why do we need this report? Information about river health tells vide an integrated measure of the health of river systems. TO KNOW ABOUT RIVER HEALTH? us about the range and quality of goods and services that a partic- The RHP also supports ular state of the river system can deliver. It also tells us about the A collaborative venture the NEMA which is People need rivers. Human and economic well-being are directly sorts of impacts that a river system can absorb. This information largely concerned or indirectly dependent on the goods and services provided by helps us to manage our rivers because with an understanding of The River Health Programme consists of partnerships that are with governing river systems. For example, we obtain drinking water and water river health we can set goals and decide on action steps for critical for the success of the programme. At the national level, the sustainable for irrigating crops from rivers, we may fish, harvest reeds, have achieving a desired river state that would ensure the provision of DWAF plays the lead role while the Department of Environmental use of the picnics on the river banks or perform baptisms in river pools. a preferred range and quality of goods and services. River health Affairs and Tourism (DEAT) and the Water Research Commission environment Some goods and services provided by rivers are important for information collected over a period of time also allows us to (WRC) are key partners. RHP activities are co-ordinated at a and the protection human survival, such as water for drinking and subsistence fishing. track changes in river health and therefore our progress towards provincial level where collaboration plays an important role. Each of ecosystems Other uses of goods and services support social needs (e.g. recre- (or away from) a defined goal. province has a network of implementers who work together, usu- (including rivers). ation, such as swimming) and economic growth (e.g. agricultural ally under the leadership of a Provincial Champion. This act calls and industrial production). Why be involved? for information Through actively working together and sharing skills and about the Some goods and services may be lost, or reduced in diversity, Many aspects of our survival and economic growth are critically resources, implementation teams can achieve goals that would not current state quality and/or quantity, when a river system is impaired. The sus- affected, directly or indirectly, by the health of our rivers and by be possible for any one organisation working alone. The imple- of ecosystems tained use of a range of goods and services is therefore directly the decisions that change their ability to deliver a range of goods mentation team for KZN was elected at an open workshop as well as changes dependent on the ecological health of a river. (The term "river and services. Therefore, the decisions around what we want and in 1997. A cross-section of organisations have contributed since in state over time, health" simply refers to the condition of a river, in the same way need from our rivers and the way we share the benefits, should be then, including the DWAF, the Town and Regional Planning indicating where as health would refer to the condition of a person or an econo- made jointly. In order to make informed decisions, we need Commission, Umgeni Water,The Umlaas Irrigation Board, Richards environmental my). In order to protect our ability to use and benefit from river appropriate and trusted information. It is in the field of river Bay Minerals, eThekwini Municipality, Mhlatuze Water, Universities impacts are occurring goods and services over the long term, we must look after the health monitoring and reporting that the River Health Programme of Zululand and Natal, KZN Wildlife, Farmer Support Group and providing guidance health of our rivers and their ability to provide these goods and contributes to informed decision-making in support of sound river (Ntshongweni Catchment Project), CSIR and Alletson Ecologicals. for the planning of services. management. future developments. 5 4 I NTRODUCTION MEASURING RIVER HEALTH INDEX OF HABITAT INTEGRITY (IHI) Habitat availability sedimentation or scouring of the river bottom, alteration of the FISH ASSEMBLAGE INTEGRITY INDEX and diversity are major determinants of the suite of fauna and water quality by the addition of contaminants, and changes in the (FAII) – Fish, being relatively long-lived and Many factors influence the health of a river ecosystem: viz. geo- flora found in a specific ecosystem. Therefore, knowledge of the natural flow regime of the river due to the presence of dams mobile, are good indicators of longer term morphological characteristics, hydrological and hydraulic process- quality of habitats is very important in an overall assessment of and/or major abstractions. influences on a river reach and the general es, chemical and physical water quality and the nature of instream ecosystem health. The IHI is designed to assess the impact of habitat conditions within the reach. and riparian habitats. Measuring each of these in detail would be