M.Sc. / The lower Thukela River catchment supports the highly industrialised Mandini/Sundumbili Industrial Complex, which in turn supports Tugela Rail, a textile factory, a vegetable-oil factory, as well as the Sundumbili Sewerage Treatment works. All of these industries release their wastes into the Mandini River that leads into the lower Thukela River. Another major potential impacting factor on the lower Thukela River is the Sappi Tugela pulp and paper mill that has both abstraction and discharge points in the same region. In 2004 the Department of Water Affairs and Forestry completed a comprehensive Reserve Determination study for the Thukela River. Upon reviewing the results it was clear that many of the variables assessed were of low confidence or there was not sufficient data collected within the region of the Mandini and Thukela River confluence and further downstream (Resource Unit K). Therefore the previous studies were not able to determine the degree to which the industries in the lower Thukela system impacted upon the integrity of the system. The aim of this study was therefore to assess the contributing impacts of the Tugela pulp and paper mill and other industrial activities on the ecological integrity of the lower Thukela River. This was done by through a toxicity assessment of the potential impacts of effluent and wastewater using the Direct Estimation of Ecological Effect Potential (DEEEP) methodologies. The toxicity of pulp and paper effluent from the Thukela mill and the receiving water body was compared to effluents from two other mills (Stanger and Ngodwana), assessing the water quality in relation to the input of different industrial effluents in the lower Thukela River. The general integrity of the lower Thukela River in relation to the input of different industrial effluents was assessed using the Habitat Quality Index (HQI), Habitat Assessment Index (HAI), macroinvertebrate and fish population studies. These studies were integrated to derive the Ecostatus of the lower Thukela River using the Macro-invertebrate and Fish Response Assessment Indices (MIRAI and FAII respectively). The toxicity testing (DEEEP) showed the paper mill effluent in the Mandini River was the least hazardous whilst Ngodwana effluent showed the highest potential to elicit a harmful impact on the receiving water body. The latter effluent displayed the highest LC50 values for the fish and the Daphnia toxicity tests, as well as an extremely high base-pair substitution mutagen activity. Toxicity was also found in algae at 100% raw effluent exposure. Tugela and Stanger mill effluent samples were very similar in their toxicity, except that Stanger effluent showed greater mutagenicity potential with exceptionally high values of revertants. The Tugela effluent samples showed no concerning levels of mutagenicity. The fish showed lower levels of response to the Tugela sample when compared to the Stanger sample. Thus comparatively the Thukela system is regarded to be the least at risk with regards to effluent discharge into the receiving water body. The lower Thukela River integrity assessment showed a sharp increase in temperature below the discharge point of the pulp and paper mill effluent. This was attributed to the excessive temperatures recorded in the pulp and paper effluent itself. There was further decrease in dissolved oxygen, which was due a combination of the industrial waste water in the Mandini River and the pulp and paper effluent. The increased organic content in the sediments of the lowest site situated downstream (TR5) is a combination of both reduced velocity of the stream flow entering the upper reaches of the estuary as well as increased organic material entering the river via the pulp and paper effluent and the Mandini River above TR3-D. This was accompanied by increased contribution of fine particle size sediments to the overall sediment composition. Habitat conditions were near natural at sites upstream of the Mandini River and effluent discharge confluences with the Thukela River. The exception was at TR1 as the weir results in unnatural inundation of biotopes upstream. The habitat conditions around the confluences of the Mandini River and pulp and paper mill effluent discharge are diminished with a recovery noted further downstream at TR4 and TR5. Invertebrate assessment shows the upstream sites to be natural, while the impact sites were largely to seriously modified. Once again the downstream sites (TR4 and TR5) show an improvement to recover to a moderately modified state. The fish assessment also shows a decrease in the FAII score below the impacts when compared to the integrity above the impacts. However these results are of low confidence due to insufficient sampling effort as only electronarcosis, seine and cast nets were used. The Ecoclassification assessment indicated a clear decrease in Ecostatus between the sites that are upstream of the impacts caused by the industrial effluent from the Mandini River and the pulp and paper mill effluent from the effluent discharge stream. The MIRAI also clearly indicated that the major impacts are caused by the combination of the Mandini River and the pulp and paper effluent. However there was a recovery in the river further downstream from the impacts.

Wetlands are considered sensitive eco-tones that provide numerous goods and services, not only to the communities which are immediately dependent upon them, but also to the many downstream stakeholders who benefit from the hydrological influences that wetlands have on a catchment. The three main objectives of this study, the foci of which included an assessment of impacts of wetlands on catchment hydrological responses (viz. flood attenuation and streamflow regulation) in the Thukela catchment under varying geographical and climatic conditions, are: · A modification and validation of the ACRU Model’s Wetland Routine; · Assessing impacts of wetlands on hydrological responses from catchments in varying climatic regions under historical climatic conditions; and · Assessing impacts of wetlands on catchment hydrological responses for climate change scenarios by using outputs from a Regional Climate Model (RCM). The ACRU Model was selected to undertake the daily hydrological simulations, while historical climate data and climate information derived from the C-CAM Regional Climate Model were used as inputs into the model. These varying climatic inputs, as well as the changes in water fluxes between simulations with and without the wetlands routine switched on, enabled the author to assess the impacts of wetlands on catchment hydrological responses under varying climatic conditions. The ACRU wetland routine initially did not produce output in line with conceptualisation of wetlands processes. As a result of this, certain modifications had to be made to the model to ensure that the results obtained mimicked wetlands hydrological processes realistically. A validation was performed on the re-configured ACRU wetlands routine to show that the simulated results of impacts of wetlands on catchment hydrological responses were realistic when compared to findings from the literature review (e.g. in regard to streamflow regulation and flood attenuation). These validation results also show that the impacts of wetlands on catchment hydrological responses are dependent on the level of soil water saturation of the wetland at the start of a streamflow event and the volume of the streamflow event in relation to the relative size of the wetland. The results further illustrate that wetlands have a relatively small flood attenuation and streamflow regulation impact on mean annual catchment hydrology at the outlet of the 29 136 km2 Thukela catchment. However, mean monthly results show pronounced effects (20 – 30%) of flood attenuation in the summer months and streamflow regulation throughout the year, especially in the drier winter months. The climate change scenario results illustrate that the impact of wetlands on hydrological responses are virtually entirely masked by the impact of climate change, with only minor changes shown on outflows of the Thukela between climate change scenarios without and with wetlands. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

There is a frequent need for estimates of design floods by hydrologists and engineers for the design of hydraulic structures. There are various techniques for estimating these design floods which are dependent largely on the availability of data. The two main approaches to design flood estimation are categorised as methods based on the analysis of floods and those based on rainfall-runoff relationships. Amongst the methods based on the analysis of floods, regional flood frequency analysis is seen as a reliable and robust method and is the recommended approach. Design event models are commonly used for design flood estimation in rainfall-runoff based analyses. However, these have several simplifying assumptions which are important in design flood estimation. A continuous simulation approach to design flood estimation has many advantages and overcomes many of the limitations of the design event approach. A major concern with continuous simulation using a hydrological model is the scale at which should take place. According to Martina (2004) the “level” of representation that will preserve the “physical chain” of the hydrological processes, both in terms of scale of representation and level of description of the physical parameters for the modelling process, is a critical question to be addressed. The objectives of this study were to review the literature on different approaches commonly used in South Africa and internationally for design flood estimation and, based on the literature, assess the potential for the use of a continuous simulation approach to design flood estimation. Objectives of both case studies undertaken in this research were to determine the optimum levels of catchment discretisation, optimum levels of soil and land cover information required and, to assess the optimum use of daily rainfall stations for the configuration of the ACRU agrohydrological model when used as a continuous simulation model for design flood estimation. The last objective was to compare design flood estimates from flows simulated by the ACRU model with design flood estimates obtained from observed data. Results obtained for selected quaternary catchments in the Thukela Catchment and Lions River catchment indicated that modelling at the level of hydrological response units (HRU’s), using area weighted soils information and more than one driver rainfall station where possible, produced the most realistic results when comparing observed and simulated streamflows. Design flood estimates from simulated flows compared reasonably well with design flood estimates obtained from observed data only for QC59 and QCU20B. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

The ecosystem services of the lower Amatikulu, Thukela and Umvoti Rivers are used extensively through sugarcane agricultural activities, heavy industries and rural sewage-treatment works. These activities affect the ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers. The Umvoti River is already being referred to as a „working river‟. This study aims to determine the current state of ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers and to establish trends between current and historical periods for the evaluation of changing trends in ecological integrity. Abiotic (driver) and biotic (responder) indicator components were used in order to identify and monitor any changes in the surrounding environment as well as to determine the ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers. Driver components include water quality, sediment grain size, moisture and organic content as well as habitat state, whereas responder components involve macroinvertebrates and fish assemblages. Two surveys were carried out; one during the low-flow period (5-11 August 2011) and the other during the high-flow period (20-28 March 2012). Current data and findings together with historical data from 1999 to 2010 were used to establish trends of selected driver and responder components. Water quality variables selected include general variables such as water temperature, chemical oxygen demand (COD), electrical conductivity (EC), pH and total alkalinity (TAL) as well as salts, nutrients and toxics. These variables provide indications as to the state of the water-quality component of this study. The Target Water Quality Requirements (TWQR) as developed by the Department of Water Affairs and Forestry for domestic use (Volume 1) and Aquatic Ecosystems (Volume 7) were used to evaluate the quality of the water sampled in this study. The water quality as well as quantity was also compared to historical data obtained from previous studies that have been done for the same study area. The sediment analyses were performed according to the protocol set out by the United States Environmental Protection Agency. Habitat availability, diversity and state were assessed by means of the Integrated Habitat Assessment System Version 2 (IHAS v 2) and the Index of Habitat Integrity (IHI). The water quality of the lower Amatikulu River was found to be in a slightly modified state with the majority of water quality parameters within the target values as set by the TWQG. Water quality parameters considered on the lower Thukela River such as water temperatures, oxygen levels, nutrient and salt loads occurred at elevated levels and were not within the TWQG requirements. The water quality of the Thukela River wasconsidered to be in a modified state which may cause negative impacts on the structure and function of the river, while the water quality of the lower Umvoti River was seriously modified. Sediment analyses revealed that the organic content of the Lower Amatikulu, Thukela and Umvoti Rivers was low. Sediment grain-size distributions are dominated by well-sorted larger soil grain-sizes (>500 μm) which is not ideal for the biodiversity. This is an indication that erosion and transportation are taking place in the Amatikulu, Thukela and Umvoti Rivers. The removal of riparian vegetation by agricultural activities and water abstraction contributes to the habitat deterioration as well as erosion and transportation of sediments that occurs in lower Amatikulu, Thukela and Umvoti Rivers. The use of macroinvertabrates as biological indicators in the determination of the ecological integrity, state or health of lotic ecosystems is globally well established. The South African Scoring System, version 5 (SASS 5), the Macroinvertebrate Response Assessment Index (MIRAI) and multivariate statistical analyses were implemented in order to determine the ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers. Results revealed that the SASS 5 integrity classes were generally one class higher than the integrity classes of MIRAI. SASS 5 and MIRAI integrity classes of the Amatikulu River ranged from natural (Class A) to largely modified (Class D/E) while the Thukela and Umvoti rivers ranged from natural to seriously modified (Class E/F). Fish assemblages are commonly used as key indicators to describe the ecological state of aquatic ecosystems. Methods used to sample fish included electronarcosis and a 5m wide 12mm meshed seine net. The Fish Response Assessment Index (FRAI) and multivariate statistical analyses were implemented in order to determine the ecological integrity of the lower Amatikulu, Thukela and Umvoti rivers. Results revealed that the automated FRAI integrity classes were constantly lower than the adjusted FRAI integrity classes. Automated and adjusted FRAI integrity classes of the Amatikulu River ranged from largely natural (Class B) to largely modified (Class D) while the Thukela and Umvoti rivers ranged from natural (Class A) to seriously modified (Class E/F). The current ecological integrity of the lower Amatikulu River was found to be in a largely natural, with few modifications (Class B) state. The Thukela River was found to be in a moderately modified (Class C) state while the Umvoti River was found to be in a largely modified (Class D) state. The trends in ecological integrity of the selected driver components which include water quality, sediment and habitat availability fluctuated noticeably. The general trend in water quality of the lower Amatikulu, Thukela and Umvoti Rivers slightly recovered towards 2012. Sediment analyses revealed that the sediment grain-size distribution as well as the moisture and organic contents generally remained stable. There was a decline in the general state of habitat integrity towards 2012. As a result of the decline in the habitat ecological integrity the ecological integrity of macroinvertebrates also slightly declined towards 2012. However, a noticeable improvement in the ecological integrity of fish assemblages was observed towards 2012. To conclude, the ecological integrity of water quality and fish assemblages improved towards 2012, while habitat and macroinvertebrates deteriorated and sediment stayed the same. The general and overall state of ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers did not deteriorate nor did it improve, but rather it stayed the same. Impacts on the ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers include a multitude of different sources. To prevent the current ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers from deteriorating further, a collective effort involving all parties is essential. / MSc (Zoology), North-West University, Potchefstroom Campus, 2013

The ecosystem services of the lower Amatikulu, Thukela and Umvoti Rivers are used extensively through sugarcane agricultural activities, heavy industries and rural sewage-treatment works. These activities affect the ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers. The Umvoti River is already being referred to as a „working river‟. This study aims to determine the current state of ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers and to establish trends between current and historical periods for the evaluation of changing trends in ecological integrity. Abiotic (driver) and biotic (responder) indicator components were used in order to identify and monitor any changes in the surrounding environment as well as to determine the ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers. Driver components include water quality, sediment grain size, moisture and organic content as well as habitat state, whereas responder components involve macroinvertebrates and fish assemblages. Two surveys were carried out; one during the low-flow period (5-11 August 2011) and the other during the high-flow period (20-28 March 2012). Current data and findings together with historical data from 1999 to 2010 were used to establish trends of selected driver and responder components. Water quality variables selected include general variables such as water temperature, chemical oxygen demand (COD), electrical conductivity (EC), pH and total alkalinity (TAL) as well as salts, nutrients and toxics. These variables provide indications as to the state of the water-quality component of this study. The Target Water Quality Requirements (TWQR) as developed by the Department of Water Affairs and Forestry for domestic use (Volume 1) and Aquatic Ecosystems (Volume 7) were used to evaluate the quality of the water sampled in this study. The water quality as well as quantity was also compared to historical data obtained from previous studies that have been done for the same study area. The sediment analyses were performed according to the protocol set out by the United States Environmental Protection Agency. Habitat availability, diversity and state were assessed by means of the Integrated Habitat Assessment System Version 2 (IHAS v 2) and the Index of Habitat Integrity (IHI). The water quality of the lower Amatikulu River was found to be in a slightly modified state with the majority of water quality parameters within the target values as set by the TWQG. Water quality parameters considered on the lower Thukela River such as water temperatures, oxygen levels, nutrient and salt loads occurred at elevated levels and were not within the TWQG requirements. The water quality of the Thukela River wasconsidered to be in a modified state which may cause negative impacts on the structure and function of the river, while the water quality of the lower Umvoti River was seriously modified. Sediment analyses revealed that the organic content of the Lower Amatikulu, Thukela and Umvoti Rivers was low. Sediment grain-size distributions are dominated by well-sorted larger soil grain-sizes (>500 μm) which is not ideal for the biodiversity. This is an indication that erosion and transportation are taking place in the Amatikulu, Thukela and Umvoti Rivers. The removal of riparian vegetation by agricultural activities and water abstraction contributes to the habitat deterioration as well as erosion and transportation of sediments that occurs in lower Amatikulu, Thukela and Umvoti Rivers. The use of macroinvertabrates as biological indicators in the determination of the ecological integrity, state or health of lotic ecosystems is globally well established. The South African Scoring System, version 5 (SASS 5), the Macroinvertebrate Response Assessment Index (MIRAI) and multivariate statistical analyses were implemented in order to determine the ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers. Results revealed that the SASS 5 integrity classes were generally one class higher than the integrity classes of MIRAI. SASS 5 and MIRAI integrity classes of the Amatikulu River ranged from natural (Class A) to largely modified (Class D/E) while the Thukela and Umvoti rivers ranged from natural to seriously modified (Class E/F). Fish assemblages are commonly used as key indicators to describe the ecological state of aquatic ecosystems. Methods used to sample fish included electronarcosis and a 5m wide 12mm meshed seine net. The Fish Response Assessment Index (FRAI) and multivariate statistical analyses were implemented in order to determine the ecological integrity of the lower Amatikulu, Thukela and Umvoti rivers. Results revealed that the automated FRAI integrity classes were constantly lower than the adjusted FRAI integrity classes. Automated and adjusted FRAI integrity classes of the Amatikulu River ranged from largely natural (Class B) to largely modified (Class D) while the Thukela and Umvoti rivers ranged from natural (Class A) to seriously modified (Class E/F). The current ecological integrity of the lower Amatikulu River was found to be in a largely natural, with few modifications (Class B) state. The Thukela River was found to be in a moderately modified (Class C) state while the Umvoti River was found to be in a largely modified (Class D) state. The trends in ecological integrity of the selected driver components which include water quality, sediment and habitat availability fluctuated noticeably. The general trend in water quality of the lower Amatikulu, Thukela and Umvoti Rivers slightly recovered towards 2012. Sediment analyses revealed that the sediment grain-size distribution as well as the moisture and organic contents generally remained stable. There was a decline in the general state of habitat integrity towards 2012. As a result of the decline in the habitat ecological integrity the ecological integrity of macroinvertebrates also slightly declined towards 2012. However, a noticeable improvement in the ecological integrity of fish assemblages was observed towards 2012. To conclude, the ecological integrity of water quality and fish assemblages improved towards 2012, while habitat and macroinvertebrates deteriorated and sediment stayed the same. The general and overall state of ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers did not deteriorate nor did it improve, but rather it stayed the same. Impacts on the ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers include a multitude of different sources. To prevent the current ecological integrity of the lower Amatikulu, Thukela and Umvoti Rivers from deteriorating further, a collective effort involving all parties is essential. / MSc (Zoology), North-West University, Potchefstroom Campus, 2013

Lower reaches of rivers as well as estuaries are regarded as South Africa’s most productive ecosystems due to the important functions such as providing nursery areas and feeding sites for juvenile macro-invertebrate and fish species they perform. Furthermore, ecologically healthy estuaries are not only of critical importance since they facilitate the provision and recirculation of nutrients, they also provide conduits for fish migrations into the fresh water system and act as buffers during floods. In South Africa, these functions are continuously being threatened by residential and/or industrial developments. It is thus essential to determine the ecological integrity (structure and function) of these systems. An Ecological integrity study was carried out on the selected rivers in Kwazulu Natal between 2015 and 2017. This study was assessed in terms of selected abiotic drivers on specific biological responses. The study was carried out according to the guidelines of the ecological determination methodologies and the resource directed measures for aquatic resources as set out by the Department of Water Affairs and Forestry, South Africa. Surveys were carried out during summer and winter seasons. Abiotic and biotic monitoring was carried out at four sites along each estuary. The abiotic component such as sediment composition and physio-chemical properties of the water was analyzed using standard methods. The biotic and abiotic components were analyzed using various indices, where applicable. The ecological integrity of the system can be accessed on the basis of its ability to carry out its natural functions. Results showed the various anthropogenic activities in the upper reaches of each river contributed to the high modified state of some of these rivers’ unacceptable water quality, loss and/or modification of habitat and an altered hydrological pattern due to impacts by agricultural, industrial and domestic uses. The ecosystem services of the lower areas of the rivers under investigation are used extensively through sugarcane agricultural activities and heavy industries works inclusive of sand mining and rural sewage-treatment. These activities affect the ecological integrity of the rivers and ultimately the estuaries. This study aimed at determining the current state of ecological integrity of five selected rivers in KwaZulu Natal and to establish trends between current and historical periods for the evaluation of changing trends in ecological integrity. Abiotic and biotic indicator components were used to ascertain changes in the surrounding environment as well as to determine the ecological integrity of these rivers. Monitoring of water quality, sediment grain size, moisture and organic content as well as habitat state, macro-invertebrates and fish assemblages was undertaken. The following variables water temperature, chemical oxygen demand (COD), electrical conductivity (EC), pH and total alkalinity (TAL) as well as salts, nutrients and toxics were investigated to provide indications as to the state of the water-quality of these rivers. The Target Water Quality Requirements (TWQR) as developed by the Department of Water Affairs and Forestry for domestic use (Volume 1) and Aquatic Ecosystems (Volume 7) were used to evaluate the quality of the water sampled in this study. Historical data obtained from previous studies of similar study areas have also been evaluated. Sediment analyses were performed according to the protocol set out by the United States Environmental Protection Agency. As a result of the abiotic drivers, results showed that the invertebrate reside in modified state. Physio-chemical, geomorphological and hydrological changes in this system resulted in the rivers’ suffering a loss in both biological and ecological function as well as aesthetic value. It is apparent from the above that there is not a need for rehabilitation but also a need for effective and continuous management strategies. These strategies can only be successful if the bio-monitoring of the system includes the effects at both economical and social levels. The water quality of the rivers under this investigation was found to be in a slightly modified state with the majority of water quality parameters falling within the target values. Water quality parameters of the lower Thukela River, not within the required target, was highly elevated and could possibly cause negative impacts on the river functionality. The water quality parameters of Umvoti river, Umdloti river and uMngeni river were seriously modified. The sediment clearly indicated that the organic content of the all the rivers was low and directly relating to the possibility of erosion and transportation taking place in the Rivers. The removal of riparian vegetation by agricultural activities, sand mining and water abstraction contributed to the destruction of the habitats along all these rivers. The South African Scoring System, version 5 (SASS 5), the Macro-invertebrate Response Assessment Index (MIRAI) and multivariate statistical analyses were implemented in order to determine the ecological integrity of the rivers. Results revealed that the SASS 5 integrity classes were generally one class higher than the integrity classes of MIRAI. The Fish assemblage methods used to determine fish samples included electro-narcosis and a 5m wide 12mm meshed seine net. Impacts on the ecological integrity of the Rivers under investigation have been assessed by various sources. To protect the current ecological integrity and further destruction of the rivers under investigation, direct involvement by the relevant authorities is of paramount importance. / Agriculture and Environmental Science / D. Litt. et Phil. (Environmental Science)

The connection between water and human wellbeing is increasingly causing concern about the implications of water scarcity on poverty. The primary fear is that water scarcity may not only worsen poverty, but may also undermine efforts to alleviate poverty and food insecurity. A review of literature revealed that the relationship between water scarcity and poverty is a complex one, with water scarcity being both a cause and consequence of poverty. Furthermore, water scarcity is multidimensional, which makes it difficult to define, while it can also vary considerably, both temporally and spatially. Finally, the relationship between water scarcity and poverty is a difficult one to quantify. Within the context of water scarcity, indicators are viewed by many development analysts as appropriate tools for informing and orienting policy-making, for comparing situations and for measuring performance. However, simplistic traditional indicators cannot capture the complexity of the water-poverty link; hence a proliferation of more sophisticated indicators and indices since the early 1990s. The Water Poverty Index (WPI), one of these new indices, assesses water scarcity holistically. Water poverty derives from the conceptualisation of this index which relates dimensions of poverty to access to water for domestic and productive use. However, the WPI has not been applied extensively at meso-catchment scale, the scale at which water resources managers operate. In South Africa, the Thukela Catchment -in the province of KwaZulu-Natal presents a unique opportunity to assess the WPI at this scale. The Thukela is a diverse catchment with respect to physiography, climate and (by extension) natural vegetation, land use, demography, culture and economy. While parts of the catchment are suitable for intensive agricultural production and others are thriving economic centres, a large percentage of the population in the catchment lives in poverty in high risk ecosystems, with their vulnerability exacerbated by policies of the erstwhile apartheid government. Many rural communities, a high percentage of which occupy these naturally harsh areas, have low skills levels, with a high proportion of unemployed people, low or no income and low services delivery. Infrastructural development, which relates to municipal service delivery, is often made prohibitively expensive by the rugged terrain in which many people live. As in other catchments in South Africa, the Thukela is affected by policies and initiatives aimed at accomplishing the objectives of post-1994 legislation such as the South Africa Constitution and the National Water Act. The potential of the WPI to assess the impacts of these initiatives on human wellbeing and to inform decision .making in the Thukela catchment was investigated. An analysis of a 46 year long series of monthly summations of daily values of streamflows output by the ACRU agrohydrological simulation model has shown that the Thukela, in its entirety , is a water-rich catchment. The reliability of the streamflows, which has implications for communities who collect water directly from 1 streams, is high along main channels but can be considerably less along low order tributaries of the main streams. The flow reliability along the small tributaries is less in winter than in summer. A high percentage of the catchment's population, in addition to being poor and not having access to municipal services, live near, and rely on, the small tributaries for their water supplies. Admittedly, this analysis addresses only one dimension of water poverty, viz. physical water shortage. Nevertheless, the study revealed that despite the Thukela's being a water-rich catchment, many communities are still water stressed. A more holistic characterisation of the water scarcity situation in the Thukela catchment was achieved using the WPI. A review of possible information sources for computing the WPI in South Africa found that many monitoring programmes, information systems and databases are either in existence and are active, or being restructured, or are under different stages of development. If and when they are all fully functional , they should be able to support national assessments of the WPI at meso-scale without the need to collect additional information. A combination of information from some of the active databases and secondary data from other local studies was used to compute the WPI in the Thukela catchment. The assessment uncovered the following: • There is an apparent association between water poverty and socio-economic disadvantage in the Thukela catchment. • There was an improvement in the water poverty situation in most parts of the Thukela catchment between 1996 and 2001, although the degree of improvement varied from subcatchment to subcatchment. Climate change, if it manifests itself by higher temperatures and reduced rainfall, will most likely worsen water poverty throughout the Thukela catchment, with the subcatchments in which many of the poor communities are located being more likely to experience the most severe impacts as the coping capacities of those communities are already strained under current climatic conditions. The findings of this study illustrate the potential of WPI as a tool for informing decision making and policy evaluation at the meso-catchment scale at which many water-related decisions are made. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.