Environmental Impacts
of Dam Water Quality in
KwaZulu-Natal: A Case
Study Approach
Author: Mendy Shozi (Cand. Sci. Nat.) [BSc: Applied Chemistry; BSc (Hons) Environmental Sciences (UKZN)]
Co-Author: Abulele Adams [BSc: Environmental Sciences; BSc (Hons) GIS (NMMU)]
Outline
1. Introduction
2. Case Study Introduction
2.1. Impact on the four dams
2.2. Case study findings
2.3 Umgeni Water results
3. Discussion on findings
4. Lessons learnt
5. Way forward
1. Introduction
• South Africa is facing a looming water
crisis
• Unsustainable social and economic
activities
• Metropolitan and residential areas in
South Africa are situated in watersheds of
rivers
e.g. Umgeni Water Catchment
Introduction
Figure 1: Residential and commercial areas in close proximity to Umgeni River
• Umgeni Water is a state-owned water
utility
• Committed to protecting, conserving and
sustaining natural resources
• Umgeni Water ‘Water Quality
Management Plan’:
1. Monitoring quality of raw water
2. Assessing risks
3. Catchment management activities
4. Improving water quality
2. Case study introduction
• The catchment is characterised by a myriad of
anthropogenic activities.
• Biological and chemical water-borne pollutants
contaminate water storage supply.
Figure 2: Location of the four dams on Umgeni River
2.1 Impact on the four dams
• Agriculture chemical pollutants (pesticides, fertilizers)
• Livestock microbiological pathogens
• Alien invasives and plantations blocks and reduces
natural flow and may cause soil erosion - sedimentation
• Commercial Activity (residential and industry) various
chemical pollutants
• Residential run-off chemical pollutants, micro-
biological pollutants
• Overflowing sewage and wastewater works chemical
pollutants, micro-biological pollutants
• Wetland destruction cannot filter impurities in systems
2.2 Case study findings
Case study findings
2.3 Umgeni Water Results
(2012 and 2013)
• Dam water quality as determined by Umgeni Water (2012;
2013): Bio-assessment tool
Figure 3: The quality of impoundments in the Umgeni River
catchment *(Source: Umgeni Water Annual Report 2011/2012; 2012/2013)
3. Discussion of findings
• Case study findings show that dam
catchments water quality contaminated
• Socio-economic and health impacts of
polluted dam and river water.
• Umgeni Water Annual Report 2012/2013
reports less contamination.
• Disadvantages of solely using biological
assessment.
4. Lessons learnt
• Numerous benefits associated with
effective dam catchment management
• Need multi-faceted water quality
monitoring scheme
• Reduction of treatment costs
• Improved ecosystem goods and services
received from river catchment
• Reduced health risks to water users
(domestic, recreational)
5. Way forward
• Need for effective integrated water information
system (NIWIS)
• Polluters must be held accountable
• Reduce pollution sources
• Greater transparency between local/national
government, industry and community members
regarding the way forward
• Water resource management projects, e.g.:
1. Working on Wetlands
2. DUCT River Walk
6. References
Brighton N (2013) Saving Midmar – Meeting Today. River Walks: Journey from the source to the sea
Görgens A and de Clercq W (2005) Research on Berg River Water Management: Summary of water quality information system
and soil quality studies. Gezina, Water Research Commission
Govender D (2011). Midmar Muck. M-NET, Carte Blanche report. Article 4358.
Jogiat R (2013) Save the Midmar Dam Project: Working together for water security in the uMgungundlovu Water Service
Authority. SANBI
Papu-Zamxaka V, Mathee A, Harpham T, Barnes B, Rollin H, Lyons M, Jordaan W and Cloete M (2010) Elevated mercury
exposure in communities living alongside the Inanda Dam, South Africa. Journal of Environmental Monitoring, 12 (2): 472-477
Todd, C. and Claasen, M. (2000). Strategic Assessment of the Baseline Environmental Context in Cato Manor: water resources.
LEAD Programme in Technology for Enhanced Environmental Management. Durban, March, 2000.
Umngeni_Water (2012) Annual Report 2011/2012, Chapter 10: Conserving our natural resources. KwaZulu-Natal,
Umngeni_Water (2013) Annual Report 2012/2013, Chapter 9: Conserving our natural reources. KwaZulu-Natal,
WRC (2002) State of Rivers Report: uMngeni River and neighbouring rivers and streams. Pretoria, Water Research
Commission
