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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Water resource decision making in the Western Cape system analysis

Van Zyl, Hugo January 1998 (has links)
Bibliography: pages 138-151. / Water resource decision making in Greater Cape Town is characterised by numerous, often conflicting goals. Among these are ensuring engineering feasibility and flexibility of supply, maximising water yield, minimising costs and minimising negative environmental and social impacts. Furthermore, in the face of ongoing development, decisions on future water supply options can be expected to increase in complexity along with the potential for conflict as natural resources become more scarce. In the present political climate, the need to transform public sector decision making into a democratic and transparent process has been recognised. Stakeholder groups need to be satisfied that their interests are taken into account in decision making and that decision makers are accountable for their actions. This thesis argues the case for the use of a formal framework to improve future decision making between water supply options in light of the above goals. After debating which type of framework would be most appropriate, the possible workings of a future system are briefly outlined.
2

The history and application of shadow pricing in South African water projects

22 June 2011 (has links)
M.Comm / This dissertation comprises of four parts that attempt to explain the history and application of shadow pricing in South African water projects with reference to water resource development and water pricing reforms. Water is a precious resource and people simply cannot survive without fresh water. It becomes a vital function to then price water correctly and therefore revolutionise the way water is treated. The application of CBA has become increasingly important over recent years Governments often finance these projects, but there is a need for a consistent or standard framework to evaluate capital projects to minimise the risk and possible losses. As a result a manual and method to evaluate spending priorities was developed in the 1980’s in South Africa. CBA has found extensive applications in the field of water development. Important issues such as the opportunity cost of water and a method to calculate the economic value or the opportunity cost of water have been developed further in South Africa over the past few years. It emphasises that pricing water can be a complicated process affected by various forces, many of which are difficult to define and model. The History and Application of Shadow Pricing in South African Water Projects Page v This dissertation demonstrates that the strategies employed in each country are different variations of CBA, with the use of shadow pricing and are adapted to each countries varying circumstance. The political experiences in South Africa have placed strain on the countries scarce national resources. As a result there is a need for some kind of framework and method to evaluate spending and pricing of infrastructure and importantly the development of water pricing reforms and management thereof. The study concludes that there is limited literature that actually defines and explains how shadow prices are calculated in water resource management. Wrong policy or planning decisions can often be a result of price distortions. Therefore, countries are becoming more aware that external factors, such as social welfare and the environment need to be taken into consideration.
3

Water resource management in South Africa.

Berjak, Leonie Karen. January 2003 (has links)
South Africa is a semi-arid country virtually surrounded by water, yet fresh water is a scarce commodity and much of the population is currently without potable water. Water is the essence of life and a renewable resource that changes through the hydrological cycle. The 1996 Constitution produced a new framework for water legislation in South Africa, culminating in National Water Act, 1998 and the Water Services Act, 1997. This study assesses the change in the approach to water resource management brought about by these Acts. In addition, the Water Research Act, 1971 was reviewed. This legislation introduces an holistic approach of integrated water resource management that recognises mutual dependence of water and land management at local catchment level to ensure sustainability. Water is also no longer divided between private and public sectors, but is deemed to be a national resource under the trusteeship of the State for the benefit of present and future users to ensure the Constitutional right of access to sufficient water. Additional important features include: recognition of the hydrological cycle; the concept of a Reserve; change of institutional responsibility from national to catchment management with associated cooperative governance and public participation; receiving water quality objectives of the individual resource; and demand management approach to water supply. Implementation of this approach is through a two-tier strategy, namely a national water research strategy and catchment management strategies for each defined water management area, that will link to the water services development plans. The national strategy filters fundamental principles to each catchment strategy, focusing on the water resource as well as potential pollution sources. In turn, each catchment strategy will provide information for input into the national strategy and water resource information system. The water services development plan will provide data for the water services and water resources national information systems, as well as the catchment strategy. However, the National Government policy of providing basic water services free may hinder the financial sustainability in effectively providing this function. These strategies and plans are part of a planning process that requires review and progressive improvement and change according to the changing needs of both the resource and society. The institutions responsible for driving this process are the catchment management agency for the catchment strategy and the water services authority for the water services development. Overall the approach to water resource management in South Africa is based on classification of river systems; determination of the reserve; international obligations; and equitable and sustainable allocation of the remaining resource through licensing and registration. Although integration and sustainability are complex issues, the Acts provide a competent framework for the link between water resources protection and water services provision. Success and sustainability of water resources management in South Africa is dependent on cooperative governance, integration of environmental factors, public participation and education, administrative compliance and financial capacity. / Thesis (LL.M.)-University of Natal, Pietermaritzburg, 2003.
4

Appropriate positioning of modelling as a decision support tool for surface water resources planning in South Africa

Dube, Renias Admore 24 August 2006 (has links)
The availability of adequate information is one of the basic requirements of sound water resources development. Simple water resource development options that required less detailed studies have already been developed, such that development proposals today require more detailed and comprehensive studies. Among other factors, these studies generate information on the hydrological risk of implementing water resources projects. The modelling tools used to generate water resources information are usually complicated by the many variables involved, which are inter-linked and usually unpredictable. The National Water Act (Republic of South Africa, 1998) emphasises the need for integrated water resources management, social equity, and ecological sustainability, which have added new dimensions to water resources planning. Water catchment simulation models that account for all the dimensions of water resources planning and bring more information than ever before to the decision-maker have become the preferred tools. Whilst earlier water resources planning tools are still in common use, this study found that these earlier tools lagged behind developments in important aspects such as national legislation, water stakeholders’ working environment, and rapid changes in computer software and hardware. The appropriateness of water resources modelling tools in South Africa was investigated in the light of a changing water environment as well as the need to address specific factors that are unique to South Africa. The water resources factors investigated included hydro-climatic, water institutional frameworks and stakeholder needs, available expertise and technological aspects of the available water management and planning tools. On the basis of the outcome of the investigation of South Africa’s unique water environment, recommendations and guidance were developed with the aim of developing a preferred local water resources modelling approach. This study investigated and recommended the use of water resources system models which are based on up to date modelling and Information Technology (IT) developments, such as HYDRO25, for multi-criteria planning of integrated water resources. In this study, the development of object oriented programming (OOP) models with visual interfaces that fit in the popular Windows operating environment was distinguished as a key aspect of water resources modelling. This modelling route was selected because it generates tools that are more user-friendly, have visual clues that relate closely with the physical system, including easy GIS integration, can handle the higher computer memory volume demands of longer time series data, and could handle a greater number of parameters as well as the increasingly more complex management scenarios. In the OOP approach, modelling tools are easily integrated with the input processing and output analysis objects that are developed separately before integration into the main model framework. All the separate software objects can easily be utilised in other models when the need arises. The HYDRO25 model uses modular objects and a visual-based programming language that easily accommodates integration with other software objects based on the component object model system. This has made further upgrading and redevelopment of the model easy to handle. In this study, the HYDRO25 model was developed and used in the Doring River catchment as a case study which was aimed at providing first-hand information about model development and application in South Africa. In the HYDRO25 model, computer code was used systematically to handle the catchment hydrology, geographical information, climatic factors, water use, catchment development proposals, the requirement of water legislation, and other factors to provide information that is useful for decision-making. In the Doring River case study, proposed irrigation developments in the Koue Bokkeveld and Aspoort area of the Western Cape were assessed using the HYDRO25 model to determine the most viable development options from a hydrological perspective. The study showed that the full irrigation potential of the catchment cannot be utilised with the available surface water resources in the catchment. The model simulation results showed that a maximum of 700 hectares can be irrigated in the Koue Bokkeveld area without creating additional water storage. Analysis of the Aspoort irrigation scheme showed that the irrigation area should be limited to 1000 hectares, with the proposed 178 million m3 Aspoort Dam being developed to support irrigation water demand and, to a small extent, to contribute to other water uses in the catchment, such as ecological flows and domestic uses. / Thesis (PhD (Water Resources Management))--University of Pretoria, 2007. / Microbiology and Plant Pathology / unrestricted
5

Non-revenue water : most suitable business model for water services authorities in South Africa : Ugu District Municipality

Mwelase, Lorraine Thulisile January 2016 (has links)
Submitted in fulfilment of the requirements for the degree of Master of Engineering, Department of Civil Engineering and Surveying, Faculty of Engineering and the Built Environment, Durban University of Technology, Durban, South Africa, 2016. / Water is a critical resource in Southern Africa. The region thus needs to protect both the quality and the quantity of its water resources through robust water conservation and demand management (WC/DM) measures. Water demand management encompasses activities that aim to decrease water demand, improve the efficiency of water use and prevent the deterioration of water resources. Water conservation refers to policies, measures or consumer practices that promote the conservation of water resources. Water resources should be used wisely to secure a water supply that is of good quality and enough for South Africa’s people and its natural environment, which provides the ecosystem that supports all forms of life. When a water utility systems experience water losses, the amount of water available to consumers is reduced, making it difficult to satisfy demand. Water losses also occur as a result of inaccuracies in customer meters, data errors in the billing system and unauthorised consumption. Such losses result in non-revenue water (NRW), which is a serious threat to the water supply sector. NRW refers to the water that is produced and lost without generating revenue for the utility. This research study investigated strategies that could be used to address the challenge of water losses, by developing a more suitable business model that could be incorporated into Ugu District Municipality (DM)’s existing NRW reduction strategies. The study was carried out in Amandawe and Umzinto zones of the District Municipality and it covered the period 01 March 2014 to June 2015. The study objectives were made up of four components. The first was to identify and prioritise the implementation of NRW reduction strategies. This was achieved by identifying the pipes to be closed off, which were supplying a significant number of consumers. For those pipes that were not closed off, flow meters were installed to measure the flow into and out of a zone. The system was then tested for zero pressure by isolating all closed valves to ensure that there were no potential feed-backs into the zone. Pressure gauges were set up on standpipes for routine pressure monitoring. The test was run at night (between 01.00 and 05.00 hours) when the system was under pressure. When the pressure dropped consistently, this meant that there was no feedback into a zone. Leaks were detected by logging the system in order to obtain night flows, which were analysed to determine the system behaviour. The results for Amandawe Zone after implementation of the pressure management programme, indicated that the average zone’s night pressure (AZNP) decreased from 7.38 bars to 5.95 bars. For Umzinto Zone, the AZNP dropped from 5.5 bars to 3.3 bars. The minimum night flows (MNFs) dropped from 34.80 m3/hr to 15.20 m3/hr in Amandawe Zone and from 6.4 m3/hr to 1.70 m3/hr in Umzinto Zone. The daily cost of excess night flow due to bursts was reduced from R2276.17/day to R862.61/day in Amandawe Zone and from R361.24/day to R40.46/day in Umzinto Zone, which provided huge savings. The second objective was to identify the sources and causes of water losses in the study area by conducting field measurements and observations. This was achieved by physically inspecting the infrastructure using visual observation, mechanical listening sticks, correlators, ground microphones and system loggers. The following indicators were used to physically identify underground leaks: unusually wet surfaces in landscaped areas, pools of water on the ground surface, noticeably green, soft and mouldy areas surrounded by drier surfaces, a notable drop in water pressure or flow volume, unexplained sudden increase in water demand or water use at a fairly steady rate for several billing cycles, cracks in paved surfaces, potholes or sink holes and the sudden appearance of dirty water in the main distribution system. For this study, the water losses in the system were found to be as a result of various causes including leaks, aging infrastructure, high pressure in the system, damaged pipes and illegal connections, among others. The third objective was to construct a water balance in order to determine the key performance indicators for the NRW reduction strategies. This was achieved by determining the system input volume (SIV), billed authorized consumption (BAC), unbilled metered consumption (UMC), unbilled unmetered consumption (UUC), real losses (RL), apparent losses (AL) and IWA Key Performance Indicators. Bulk and domestic meter readings were used to calculate the components of the water balance. The results of the water balance indicated that there was a decrease in the SIV from 904 kL/day to 523 kL/day in Amandawe Zone and from 382 kL/day to 221 kL/day in Umzinto Zone. The physical water losses were reduced from 611 kL/day to 377 kL/day in Amandawe Zone and from 93.8 kL/day to 45.8 kL/day in Umzinto Zone. The NRW was reduced from 659 kL/day to 395 kL/day in Amandawe Zone and from 94.2 kL/day to 46.2 kL/day in Umzinto Zone. The fourth objective was to develop the most suitable business model for Ugu DM based on the results arising from the first three objectives. Ugu DM needs to ensure both operational and financial efficiency. Operational efficiency could be achieved by minimising real water losses through reviewing water services standards, developing district metering areas, pressure management, leak detection and repair, reservoir control to stop overflows and pipe replacement programs. Financial efficiency could be achieved by carrying out regular meter testing and calibration, securing database integrity, managing illegal connections, ensuring that all customer connections have meters and ensuring that the tariff structures were cost reflective in order for the municipality to cover costs and generate revenue. Findings of this study could assist other water utilities operating under similar conditions. The implementation of this study’s results could have positive economic, social and environmental effects on Ugu DM. It was concluded that rezoning, pressure management and leak detection were the most critical NRW reduction strategies as they had a positive impact on the system. The main causes of leaks in the system were identified as aging infrastructure, high pressures in the system, and illegal connections. All the critical KPIs of IWA water balance responded positively after the implementation of the strategies by reducing. The operational and financial efficiencies were identified as critical for a WSA to develop a business model that could sustain itself.
6

Real time optimal water allocation in the Orange River catchment in South Africa

Olofintoye, Oluwatosin Onaopemipo January 2015 (has links)
Submitted in fulfillment of the requirements of the degree of Doctor of Engineering: Civil Engineering, Durban University of Technology. Durban. South Africa, 2015. / The planning and management of water resources systems often involve formulation and establishment of optimal operating policies and the study of trade-off between different objectives. Due to the intricate nature of water resources management tasks, several models with varying degrees of complexities have been developed and applied for resolving water resources optimisation and allocation problems. Nevertheless, there still exist uncertainties about finding a generally consistent and trustworthy method that can find solutions which are very close to the global optimum in all scenarios. This study presents the development and application of a new evolutionary multi-objective optimisation algorithm, combined Pareto multi-objective differential evolution (CPMDE). The algorithm combines methods of Pareto ranking and Pareto dominance selections to implement a novel generational selection scheme. The new scheme provides a systematic approach for controlling elitism of the population which results in the simultaneous creation of short solution vectors that are suitable for local search and long vectors suitable for global search. By incorporating combined Pareto procedures, CPMDE is able to adaptively balance exploitation of non-dominated solutions found with exploration of the search space. Thus, it is able to escape all local optima and converge to the global Pareto-optimal front. The performance of CPMDE was compared with 14 state-of-the-art evolutionary multi-objective optimisation algorithms. A total of ten test problems and three real world problems were considered in the benchmark of the algorithm. Findings suggest that the new algorithm presents an improvement in convergence to global Pareto-optimal fronts especially on deceptive multi-modal functions where CPMDE clearly outperformed all other algorithms in convergence and diversity. The convergence metric on this problem was several orders of magnitude better than those of the other algorithms. Competitive results obtained from the benchmark of CPMDE suggest that it is a good alternative for solving real multi-objective optimisation problems. Also, values of a variance statistics further indicate that CPMDE is reliable and stable in finding solutions and converging to Pareto-optimal fronts in multi-objective optimisation problems. CPMDE was applied to resolve water allocation problems in the Orange River catchment in South Africa. Results obtained from the applications of CPMDE suggest it represents an improvement over some existing methods. CPMDE was applied to resolve water allocation problems in the agricultural and power sectors in South Africa. These sectors are strategic in forging economic growth, sustaining technological developments and contributing further to the overall development of the nation. They are also germane in capacitating the South African government’s commitment towards equity and poverty eradication and ensuring food security. Harnessing more hydropower from existing water sources within the frontier of the country is germane in capacitating the South African Government’s commitment to reduction of the countries’ greenhouse gas emissions and transition to a low-carbon economy while meeting a national target of 3 725 megawatts by 2030. Application of CPMDE algorithm in the behavioural analysis of the Vanderkloof reservoir showed an increase of 20 310 MWH in energy generation corresponding to a 3.2 percent increase. On analysis of storage trajectories over the operating period, it was found that the real time analysis incorporating a hybrid between CPMDE and ANN offers a procedure with a high ability to minimize deviation from target storage under the prevailing water stress condition. Overall, the real time analysis provides an improvement of 49.32 percent over the current practice. Further analysis involving starting the simulation with a proposed higher storage volume suggests that 728.53 GWH of annual energy may be generated from the reservoir under medium flow condition without system failure as opposed to 629 GWH produced from current practice. This corresponds to a 13.66 percent increase in energy generation. It was however noted that the water resources of the dam is not in excess. The water in the dam is just enough to meet all current demands. This calls for proper management policies for future operation of the reservoir to guard against excessive storage depletions. The study herein also involved the development of a decision support system for the daily operation of the Vanderkloof reservoir. This provides a low cost solution methodology suitable for the sustainable operation of the Vanderkloof dam in South Africa. Adopting real time optimisation strategies may be beneficial to the operation of reservoirs. Findings from the study herein indicate that the new algorithm represents an improvement over existing methods. Therefore, CPMDE presents a new tool that nations can adapt for the proper management of water resources towards the overall prosperity of their populace. / D
7

Water management at a base metals refinery

Osman, Ayesha January 2016 (has links)
MSc Dissertation Submitted to School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa 12 August 2016 / Most mineral processing plants have high water requirements for their operational activities. These plants often function in an environment where water is becoming increasingly scarce. An increase in population will result in an increased demand for water, potentially beyond the limits of supply, and hence increased competition for the resource. In South Africa, Gauteng and the North West Province are likely to be first to experience a shortage of potable water. The key to a sustainable future lies in understanding and utilising resources more efficiently. This holds especially for industries who seek to minimise water usage through better management of resources. The two tools used in this study are the Water Accounting Framework (WAF) and Water Footprinting (WF) method. This research assisted a refinery in the North West Province understand its water usage and move towards operating in a more sustainable manner. Site water management was improved and the objective of this research fulfilled by: (i) Surveying the potable water and the storm water systems with a view to assessing the current water accountability and determining methods to improve accountability; (ii) Determining the water balance for the site and presenting it in the form of a water balance sheet; (iii) Reporting water usage in accordance with the Minerals Council of Australia’s “Water Accounting Framework for the Minerals Industry”; (iv) Calculating the water footprints of the refinery; and (v) Evaluating the water usage at the refinery and identifying ways in which water savings could be achieved. It was seen that the biggest consumer of water was the boilers and utilities section and the biggest loss of water was through evaporation. The refinery potable water requirement (2 280 m3/y) amounted to 0.16% of the daily water use for the Bojanala Platinum District. Four reports (outputs) were generated using the WAF. The four reports generated provide a good indication of the movement of water into, out of and during a process. WFs were calculated for the process. The blue WF was calculated to be 832 363 m3 and the green WF was calculated to be 261 970 m3. The product WF was 43.9 m3/t of base metal produced. There was no grey WF as the site does not discharge polluted water. This research provided an opportunity for the refinery to improve water efficiency onsite as well as improve reporting standards. Water usage was reported using global reporting tools to set a benchmark for the base metals industry. / MT2017
8

Institutional capacity for water conservation: a case study of Sedibeng District Municipality

Likontsane, Surprise C. 14 July 2016 (has links)
A research report submitted to the Faculty of the Built Environment and Engineering, University of the Witwatersrand, in partial fulfillment of the requirement for the degree of Master of Science in the field of Development Planning (MSc DP) August 2015 / Since the democratic transition in 1994, the role of local government has changed dramatically. Local governments are now expected to play a far more active role in their constituencies. As such, municipalities are expected to implement broader national policies and legislatures. The literature reviewed as part of the research indicated that most municipalities are faced with inadequate performance skills to manage and sustain their projects. This particular study seeks to understand the institutional and human resources strengths and weaknesses that help or hinder Sedibeng municipality to actively pursue water conservation through implementing Integrated Water Resources Management (IWRM) principles. In pursuit of this purpose, a qualitative research approach was adopted with interviews conducted with Sedibeng Municipality’s seven senior officials and community members. The main findings of this study revealed that the key technical department of the water sector in Sedibeng has capacity challenges at individual and organizational level. Of special concern is the failure of the municipality to give ongoing training to staff, so as to pass on modern advanced knowledge and new technological innovation skills. This is further compounded by the mismatch between the qualifications and job descriptions of some staff members. The study also finds that public-private partnership between the municipalities and private companies is needed in the water sector to promote water conservation and thus provide a better level of service delivery. The research concludes that institutional capacity is a prerequisite for the implementation of IWRM principles. In regard to this study, it has been established that to some extent Sedibeng District Municipality has the required institutional capacity in terms of organizational arrangement to harness the principles of IWRM. The accomplishment of IWRM depends profoundly on financial and human capacity of each municipality. Therefore, the key recommendation is that the municipalities should employ individuals based on merit and work experience to ensure efficient management of funds and effective execution of water related projects. Key words: Water Conservation, IWRM, Institutional capacity, Sedibeng, Emfuleni
9

A prototype decision support system for streambank rehabilitation.

Schoeman, Kilaan Christopher. January 2001 (has links)
The condition of a stream is often judged by the state of its banks. This, the lack of adequate advice for streambank rehabilitation, and the drive by legislation, particularly the National Water Act, 1998 (RSA Act no. 36 of 1998) and the National Environmental Management Act, 1998 (RSA Act no. 107 of 1998), to restore South African riparian areas, created a need for more information into such systems. Identifying a gap in what we know about rehabilitating degraded streambanks led to the development of a decision support system for the selection of streambank rehabilitation techniques. The Streambank Rehabilitation Decision Support System, or SR-DSS, aims to provide riparian managers with advice on choice of technique at degraded streambank locations along a river system. Techniques were sought from the scientific literature and organised to recommend appropriate techniques for combating certain erosive processes. Rutherford et al. (1999) conclude that placing priority on sites of lower importance may be an inefficient manner of spending the resources at hand. Foreseeing this likelihood, a priority setting system was developed and based on the principles of Rutherfurd et al. (1999). These principles aim to prioritise human interests without compromising ecological interests. Along a given stream, the areas of degradation that compromise property will nearly always have the highest priority. Once these have been addressed, sites of ecological value are taken into consideration followed by sites that require substantial effort to restore. It is argued that sites taking substantial effort to restore have the least to 'loose' should they degrade further. To enable the use of these principles a site scoring system was developed, so that sites could be prioritised. This was based on the value and threat rating tables developed by Heron et al. (1999). It was soon realised that a framework was needed within which the above could be set. For this purpose, Kapitzke's (1999) planning and design procedure was adapted to form an eleven-step framework which would guide the rehabilitation venture from priority setting, to the treatment outcome. The rehabilitation approach was tested in the case of the Foxhill Spruit. The small size of the catchment allowed the different segments of the approach (framework, priority setting model, field assessment sheet and SR-DSS) to be tested in real world conditions. The approach was found to have a number of strengths. The framework brought to the attention of the user, the dominant forces at play at each site, and was useful in determining the recommendation given by SR-DSS. The priority setting model allowed sites to be arranged in order of priority, that, according to Rutherfurd et al. (1999), would be the most efficient in terms of ecological value maintained, and resources saved. The field assessment sheet was consistent in rating the degree of intervention required, and in each case directed the user to the appropriate sections in SR-DSS. SR-DSS recommended appropriate techniques that would match the erosive forces occurring at each site. Comparing the technique chosen by SR-DSS to techniques that may have been recommended instead substantiated this finding. The techniques chosen by SR-DSS were found to be superior. This approach considers all aspects of sound streambank rehabilitation and may be used to gain advice on small streams in South Africa. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.
10

The development and application of ecological risk assessment in South African water resource management

Claassen, Marius January 2006 (has links)
The provision of goods and services by aquatic ecosystems plays an important role in socio-economic development and livelihoods in the southern African region. Water resource management in South Africa developed from an agrarian and pastoral focus up to 1956 to also supporting mining and industrial activities. This led to the introduction of the resource water quality objectives and pollution prevention approaches, which balanced the needs for development and protection. Prior to 1994, access to water resources was limited to riparian property owners and a minority of the population who controlled industrial and mining activities. The establishment of a democratic government amplified the need for accelerated socio-economic development, with equity, efficiency and sustainability being the principles of such development. New approaches were needed, which could achieve these development objectives and secure the resource base for future generations. An overview of the scientific process highlighted a risk based approach as potentially supporting the much needed balance between development and protection. The aims of this thesis is to develop a framework and process for the application of ecological risk assessment to water resource management in South Africa, to use case studies to draft guidelines for ecological risk assessment and to assess the degree to which ecological risk assessment can contribute to effective water resource management in South Africa. The United States Environmental Protection Agency’s guidelines for ecological risk assessment were identified amongst international best practice as meeting the requirements for local application. A framework was drafted for ecological risk assessment in South Africa, with the main phases being to agree on objectives, formulate the analysis plan, analyse information, characterise risk and manage risk. Modifications from the Environmental Protection Agency’s process include the order of activities in the first phase, the explicit testing of hypotheses and clarification of the evaluation of existing data or collection of new data. An industrial effluent case study was used to assess the applicability of the proposed framework. The case study dealt specifically with the assessment of risks posed by current conditions and long term licence conditions. The framework was found to be useful to identify weaknesses in the established monitoring programme and to evaluate lines of evidence to assess the degree to which the stated conditions would have unacceptable consequences. The study highlighted several weaknesses in the suggested framework, of which the most critical is the interpretation of the risk hypothesis as a testable null hypothesis. It became clear that cause-effect relationships should be stated as the risk hypothesis, whereas the assessment should evaluate expressed or expected conditions against a risk profile for a given stressor to benefit fully from the risk assessment approach. Changes to the framework terminology were suggested as well as nested feedback loops to allow for iterative processes where new information becomes available. The proposed guidelines incorporate the learning from the case study application as well as feedback from a peer review process. The guidelines incorporate the suggested actions under each phase as well as notes providing the rationale for each step. Three case study outlines were provided to assist users with the interpretation of the guidelines in different applications. The proposed guidelines are applied in an ecological Reserve determination case study, which specified the ecological water quality requirements. The study found that a risk-based approach was followed in the development of the water resource management policy, but the Reserve determination method is generally hazard based, with site specific modifications of the target values being allowed on a conservative basis. The case study highlighted a lack of readiness of water resource managers to accommodate scientific results expressed as probability distributions in support of management decisions. The thesis is concluded with a discussion of the key learning points of the ecological risk assessment development process. The evaluation highlights the move from stating and testing a null hypothesis to stating the risk hypothesis and evaluating the stated conditions against a risk profile. Several implementation challenges are highlighted, with specific recommendations made for adopting the proposed guidelines.

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