This study investigates the economics of water as used by smallholder irrigation farmers in South Africa. The productivity and value of water were estimated with data from two smallholder irrigation schemes: Zanyokwe and Thabina. Production parameters such as fertilisers, seeds, pesticides, equipment, transport, labour, and water were treated as inputs. Various methodologies used to estimate water value, including cost-based approaches, were thoroughly reviewed. The aim was to select the ones with more justification for use in smallholder irrigation sector and also to compare a number of approaches. On a case study basis, three methods were applied: residual valuation method, willingness to pay and cost-based approaches (i.e. accounting costs of O&M). Water productivity and values were then evaluated as per crop, farmer, and scheme. Also, cross-section regression analysis was used to investigate the effect of some key socio-economic factors of production on gross margin and willingness to pay. The results indicated that on average, the value of water varies according to methods, crops, farmers and schemes. In the Zanyokwe scheme, water value estimated by the residual method in cabbage is higher (R1.64 per m3) than the one in dry maize (R0.35 per m3), if intensive and high yield irrigated crops are grown per year. Also, in Thabina, water value for cabbage (R1.14 per m3) outperforms water value for dry maize (R0.02 per m3. This means that there is greater potential in vegetable crops than food grain crops, although the two schemes have different irrigation systems, and such analysis is based on one-year data, which may lack accuracy. Low water valuation is ascribed to low yield and extensive cropping systems, because gross margin per hectare is very low. This signifies the need for expansion in high value crops rather than low value crops. At farm and scheme level, the results were derived by using the Smile database and simulated platform. The Smile platform is a data capturing and a calculation tool. It calculates a number of indicators, economic figures, at scheme and individual farm level, allowing for evaluation of the current situation. The results suggested that at present, the Zanyokwe scheme requires about 1 739 255 m3 of irrigation water per year. The total operational costs (accounting costs of O&M) are about R146 097.42. In other words, supplying 1 m3at farm level will cost R0.084. This implies that if irrigation charges are levied so as to cover O&M costs of the Zanyokwe scheme, the current costs (R0.084) will form only 23% of the average gross margin of R0.37 per m3 used at scheme level. Furthermore, in the Zanyokwe irrigation scheme, the results revealed that the most active and efficient farmers (specialized farmers) can make an average gross margin of R4 105 per ha per year, also achieving the highest water productivity R0.69 in gross margin per m3 consumed. However, in the Thabina scheme, the results indicated that, to supply 1 m3will cost R0.062. Thus, the current water supply costs cover about 56 % of what is earned (i.e. R0.11 per m3 used) at scheme level. Again, the most active farmers (commercially oriented pensioners) are more efficient, with average gross margin of R3 092 per ha per year, also achieving the highest water productivity (R0.53 in gross margin per m3 used). These results suggested that certain smallholder farming systems seem capable of paying for irrigation charges of their respective schemes if they are obliged to do so. As far as willingness to pay (WTP) and cost-based approaches (CBA) are concerned, the results clearly show that the active farmers in the Zanyokwe scheme have lower WTP per m3 (R0.03) than the GM of output (R0.69) per m3 of water used. Also, the accounting cost (R0.084 per m3 of water used) is lower than the GM gained. However, in the Thabina scheme, the situation is quite different. The active farmers are willing to pay R0.19 per m3 of water used. This implies that, if farmers are to pay for the charges in order to cover O&M costs, the farmers in Thabina are ready to pay as much as three times the proposed costs of O&M (R0.062 per m3 of water used), although both the WTP and the accounting cost are lower than GM gained. In these results, it is significant that both the accounting cost and the willingness to pay are lower than the GM per m3 of water used at least in the Zanyokwe scheme. Even though the data were drawn from a sample for one year only, this finding on the perception of farmers has implications for extension and training to improve future productive use. Regarding the findings from cross-section regression analysis, the results for GM (as dependent variable) in general indicated that in the Zanyokwe scheme, only credit affects output positively and significantly. Production costs have significant effect on output, but with a negative correlation. It is striking that all the other factors of production including hired labour show negative and insignificant effects on output. In the Thabina scheme, the most important factors of production in the model are land size (hectare) and production costs (Rand per ha). These two variables influence output positively and significantly. As far as WTP (as dependent variable) is concerned, the results indicated that in the Zanyokwe scheme, it is striking that in all the investigated factors, only credit affects WTP positively and significantly. All other factors are insignificant. Also, gross margin of output per m3, unexpectedly, has displayed a negative and insignificant effect on output. In the Thabina scheme, the results show that the land size per hectare, and gross margin of output per m3 affect WTP positively and significantly. Such results are consistent with the assumptions made in the conceptual framework that a farmer with high gross margin gained at farm level is more likely to pay for water costs than those with poor gross margin. On the basis of these findings, the following recommendations were formulated. Specific policies should include promotion of high value crops and improved varieties of seed for food grain crops (e.g. maize) and vegetables (e.g. cabbage). While improved agronomic practices remain important, there is also potential to increase productivity and profitability of the crops by improving water management practices at the canal-system level, such as better timing of water delivery and increased overall canal-water supplies at the farm level. Finally, from a cost recovery point of view, government should develop a program of cost sharing for capital costs of irrigation development. With regard to inter-sectoral competition, these results highlight that, if inter-sectoral competition is left to uncontrolled market forces may result in smallholder farmers' selling their water rights to sectors which value water at higher levels. To avoid a “liberal trap” such as in the example of Chile (where smallholder farmers "en masse" sold their water rights, resulting ultimately in deeper rural poverty), some form of control/management of water rights transaction involving smallholder farmers is necessary. Finally, the findings of this study can be used in various ways. Since, these values determine the farmer’s ability to pay for water now or in the future, the incentive to use water judiciously will be governed by these values. Secondly, the results can be used to evaluate whether the costs estimated and gross margin per m3 gained at farm level, are in line with the farmers’ willingness to pay. Further work is recommended to clarify these conclusions and provide more policy clarification on the better use of water by smallholder irrigation farmers in South Africa. / Dissertation (MInst.Agrar)--University of Pretoria, 2007. / Agricultural Economics, Extension and Rural Development / unrestricted

Valuation draws heavily on the economic theory of demand. This tells us that users have preferences for water and are willing to pay different amounts for units of water put to different uses. Water should be allocated between these uses to the point that equalises the value of the last or 'marginal' unit. In other words, it is impossible to find a higher value for this marginal unit. Application of this principle of equi-marginal returns requires us to have some clarity about water values in competing uses. This is also important since water is rarely free to supply, and therefore suppliers need to charge a price that is in some sense equal to the supply cost and value to achieve full cost recovery. Even though inclusion of this economic rationale in the management of water resources has been a widely accepted principle, and is included in national and the EU policies, the actual practice does not fully reflect this endorsement. While many countries recognise the vital nature of water resources, few, if any, pursue a rigorous analysis of revealing the explicit value of water as a basis for determining whether water is actually being allocated to sectors in order to maximise its overall benefit to society. Aspiring to be the first Hydro Nation, maximising the social return from its water uses ought to be a policy objective in Scotland. This thesis constructs a portfolio of different water uses, estimating the approximate value for each and their current allocation in Scotland. This aims to stimulate an informed debate on actual allocation of water among different uses, relative values and trade-offs of these allocations in Scotland so that alternative allocation scenarios can also be discussed. I then focus on the valuation of water by manufacturing industries, the biggest consumptive use and a significant added value creator in Scotland. I investigate the factors that affect the valuation of water and the responsiveness to prices in manufacturing industries using a meta-analysis technique. These values are obviously not the same for each manufacturing sector due the nature of their use and value of their final output. Some sectors create premium value out of their use. The whisky industry stands out as a water-intensive and high value creating sector, as well as a vital contributor to the rural and overall Scottish economy. It is analysed here as the first case study using water footprint and marginal productivity analyses methods, both analyses highlighting the importance of quality and quantity of local water resources in Scotland and its value to the industry. The second case study is the livestock industry, which has been overlooked in the valuation of water use literature yet is significant for livelihoods in rural Scotland where reduced land capability limits agricultural production options. Following the portfolio of water uses, meta-analysis and case studies that analyse the current situation of value and allocation, I explore how the current situation can be improved through the application of tradability. Currently the main problem in Scotland is not the amount of water used or abstracted, but the pollution reaching water bodies as the result of run-off and leaching from agricultural fields. Therefore, the feasibility of trading water rights is more concerned with the permits to pollute rather than the rights to use. Using a linear optimisation I look into the potential of designing a payment for ecosystem services scheme based on tradability of water pollution in agricultural catchments that are affected by from diffuse pollution. The results indicate that trading schemes help reduce the cost of pollution to all users while creating additional income for farms. For constructing more precise pollution rights and robust schemes more research efforts are required.

The occurrence of organic contaminants in the drinking water value chain (from source to tap) is a growing concern for the Drinking Water industry and its consumers given the high risk these contaminants can cause to the general public. These adverse health effects include such as endocrine disruption, toxicity teratogenicity, mutagenicity and carcinogenicity. Some of these organic contaminants are included in national and international drinking water quality guidelines or standards. However, although there are similarities in the list of organic contaminants used by each organization or country, the organic contaminants are never the same given the local conditions. There are also noticeable differences in the concentration limits set as targets or criteria for organic contaminants for public health protection via the use of drinking water. A further question requiring the response from drinking water regulators was whether the standards listed in the international literature would be applicable in other countries like South Africa. Complicating this decision is the fact that the South African National Drinking Water Standard (SANS 241) does not adequately address this component of drinking water quality management. The current standard only provides for dissolved organic carbon (DOC), total trihalomethanes (TTHMs) and phenols. However, the standard contains a statement which specifies that if there is a known organic contaminant, that may pose a health threat, it should be included in the monitoring programme and evaluated against World Health Organization (WHO) guidelines. To safeguard Drinking Water industry customers, it was deemed necessary to investigate this matter and establish a tool to assist with the identification of a list of organic contaminants to be monitored in the drinking water value chain. To achieve this a specific procedure/protocol needed to be developed, hence the aim of this study which was to develop a generic protocol for the selection and prioritization of organic contaminants for monitoring in the drinking water value chain (from source to tap). To achieve this, a critical evaluation and synthesis of the available literature on the approaches for the selection and prioritization of organic variables of priority to the drinking water industry was undertaken as a first step. From the literature review it was evident that there are currently many selection and prioritization approaches which are characterized mainly by the purpose for which the exercise has been conducted for. Approaches that prioritize chemicals according to their importance as environmental contaminants have been developed by government agencies and private industries such as the Health Canada’s Canadian Environmental Protection Agency (CEPA), the United Kingdom’s Institute for Environmental Health (IEH), the European Community’s Oslo and Paris (OSPAR) convention exercise for the protection of the Northeast Atlantic marine environment and the European Union (EU)’s combined monitoring based and modelling based priority setting scheme (EU-COMMPs). A few approaches such as ones published by the United States Environmental Protection Agency (USEPA), address the needs of the Drinking Water industry and there is no generic approach to the selection, prioritization and monitoring of organic contaminants in the drinking water value chain. From the review of selection and prioritization approaches, a generic model was developed. The model consists of three main steps, the compilation of a “pool of organic contaminants, the selection of relevant parameters and criteria to screen organic contaminants and finally the application of criteria to select priority organic contaminants. It was however realized that these steps were not enough if the protocol to be develop will serve its purpose. Selection and prioritization approaches are typically intended to be fairly simple and quick methods for determining the health and environmental hazards posed by the use and release of chemical substances into different environmental systems. This was taken into account during the development of the current protocol. Understanding that a protocol is a predefined written procedural method in the design and implementation of tasks and that these protocols are written whenever it is desirable to standardize a method or procedure to ensure successful reproducibility in a similar set up, a generic protocol was developed based on the model. The protocol developed in this study, operates as a multidisciplinary contaminants management and proactive protocol, thus exchanges toxicological, water quality, agricultural, chemical and public health information. The protocol uses previous or readily available information as a point of departure. It seeks to address the challenge facing the water industry in managing the current and emerging organic contaminants that are relevant to public health protection via the use of drinking water. Once the protocol was developed, it was validated in a prototype drinking water value chain. The exercise comprised of testing each step of the protocol from the selection of the “pool of organic contaminants (Step I) to recommending the final priority list of organic contaminants (Step VII). The implementation was successfully conducted in the Rand Water drinking water value chain. Emphasis of expert judgment was made as each step was validated and the opinion of key stakeholders used to shape the process. During Step III of the protocol, an intensive literature review was conducted to determine organic contaminants that have been identified in ground and surface water systems across the world. As a result of this review, major groups of organic contaminants that have been found to occur in source water resources across the world were identified. The identified groups of organic contaminants include, pesticides, polynuclear aromatic hydrocarbons, per and polyfluoroorganic compounds, polycyclic aromatic hydrocarbons, alkanes and alkenes, C10-C13 Chloroalkanes, pharmaceuticals and personal care products [PPCPs], surfactants, benzotriazoles, cyanotoxins and Carbon-based engineered nanoparticles. The risk profile of the identified organic contaminants was established using the persistence, bio-accumulation and toxicity criteria and the development of water quality monographs as an information dissemination tool. A conceptual framework for the implementation of the protocol by water utilities and relevant institutions has been developed from the experiences learnt during the validation exercise and a priority list of organic contaminants for the monitoring in the drinking water value chain to be used by Rand Water and other water utilities was identified. Some of the organic contaminants on this are currently being analyzed for in The Rand Water’s routine organic monitoring programme. During the validation exercise, the following were noted, <ul> <li>During the identification of the “pool of organic contaminants” from the consulted information sources such as the WHO guidelines for drinking water quality, Health Canada drinking water quality guidelines, the USEPA drinking water quality standards, the New Zealand drinking water quality standards, USEPA IRIS database, the PAN-UK list of registered pesticides for South Africa, the IARC list for recognized carcinogens and the Department of Agriculture pesticides manuals duplications were observed. </li> <li>The time allocated could not allow for the development of water quality monographs for all organic contaminants of concern but for a few selected contaminants whose information was inadequate to allow for decision-making. </li> <li>The determination of concentration levels of organic contaminants in fish, sediment and water samples could have been limited by the failure of current analytical instruments to go down to lower levels at which they occur in the drinking water value chain. <l/i> <li>Only two events could be planned, during the wet season (high flow) and dry season (low flow) based on time and budget constraints. </li> <li>Although various experts were consulted and invited to attend workshops in order to validate the process, the attendance could not be extended to all nine provinces given the time and budget constraints. <br></li></ul> Based on the above, recommendations were made for the dissemination and use of the products emanating from this study. For example, it is recommended that the current protocol be made available to water utilities and the process of revising the current priority list be repeated every 5 years. Further research should be conducted to obtain full coverage of organic contaminants impacting on source water quality in all ground water and surface water systems used as sources for drinking water production. Another major recommendation is the investigation of potential analytical methods that current chromatographic methods with high resolution mass spectrometry to ensure that organic contaminants can be detected at the ng/l to pg/l using a single enrichment method in order to make sure that those organic contaminants that occur at very low concentration in environmental samples can be detected. For example, the realisation that compounds such as synthetic organic polymer residues, emerging disinfectant by-products, detergent metabolites, chlorinated benzenes, alkyl phenol, polyethoxylates, their metabolites and cyanotoxins are continuously discharged into the environment via wastewater and industrial effluent discharges which increases their concentration in aquatic environment and concomitantly their potential to exert adverse health effects in water used as source for the production of drinking water necessitates that each of these groups be added to the current monitoring programme. The current water quality monographs can be used for the benefit of the Drinking Water industry. It is also recommended that a training manual on the production and use of water quality monographs is produced to facilitate their dissemination. CD-ROMs on the water quality monographs can be produced and distributed with the manual. / Thesis (PhD)--University of Pretoria, 2010. / School of Health Systems and Public Health (SHSPH) / PhD / Unrestricted

In the aftermath of the liberalization of European Energy Markets in the 2000s, Power Exchange platforms have constantly evolved towards more integrated and competitive designs, where quality forecasts and effective optimization strategies play decisive roles. This study presents the development of a hydropower scheduling optimization algorithm for the Day-Ahead spot market using Mixed Integer Linear Programming (MILP). This work was supported by the hydro asset management team of ENGIE Global Energy Markets (GEM) located in Brussels.  The model developed is focusing on the optimization of Coindre Hydraulic Power Plant (HPP), located in the highlands of Massif Central in France. With the combined water discharge of its two interconnected reservoirs, Grande-Rhue and Petite-Rhue, the powerhouse can reach up to 36 MW of power output capacity. The two reservoirs are located kilometres apart from each other and have different storage capacities and catchment areas. The reservoirs naturally exchange water due to the level difference along an interconnection pipe. Maximum power output is limited by water level differences in both reservoirs, which makes modelling complicated. These operational constraints are a limiting factor in terms of operability, as a result the scheduling process is a non-trivial task and is time-consuming.  A framing study of the power plant was conducted over a hydraulic year to identify the governing parameters of the model. The multi-reservoir nature of the optimization problem oriented the model development towards a Mixed Integer Linear Formulation. After experimenting with different solvers, Gurobi 28.1.0 was chosen for its performance in the Branch and Cut Algorithm for the power scheduling task.  The performance of the new model has been validated by re-running the model on past production plans, results show that reservoir volume errors are less than 5% of their respective capacities on a 5 days’ time-horizon. After backtesting it was found that the new optimization strategy results in higher revenue for the plant due to the optimized operation at higher average energy prices. The results also bring out the importance of proper valve actuation in the optimization strategy, as well as the need for future studies. / Till följd av liberaliseringen av de europeiska energimarknaderna under 2000-talet har energiföretagen och elbörserna ständigt utvecklats mot mer integrerade och konkurrenskraftiga lösningar, där kvalitetsprognoser och effektiva optimeringsstrategier spelar avgörande roller. Detta examensarbete presenterar utvecklingen av en algoritm för optimering av vattenkraftplaneringen på Day-Ahead elmarknaden med hjälp av en matematisk modell av typen Mixed Integer Linear Programming (MILP). Arbetet initierades av och utfördes hos ENGIE Global Energy Markets (GEM) i Bryssel.  Modellen som utvecklats är tänkt att optimera Coindre vattenkraftverk, som ligger på höglandet inom Massif Central i Frankrike. Med det kombinerade vattenutsläppet från dess två fördämningar, Grande-Rhue och Petite-Rhue, kan kraftverket leverera upp till 36 MW el netto till elnätet. Vattenreservoarerna ligger flertalet kilometer ifrån varandra och har mycket olika kapacitet och upptagningsområden. Båda reservoarerna är kopplade till varandra genom det gemensamma tilloppsröret till kraftverket, där en reglerventil finns endast vid Petite-Rhue. Vatten kan växlas naturligt mellan de två dammarna när ventilen är öppen på grund av skillnaden i varderas vattennivå. Den maximala effekten från kraftverket är begränsad av vattennivåerna i båda reservoarerna vilket gör optimeringsmodelleringen komplicerad. Dessa operationella begränsningar är mycket hindrande vad gäller valet av driftsregim, eftersom kalkylering av driftsplaneringen blir en svår och tidskrävande uppgift.  En ramstudie av vattenkraftverket genomfördes under ett typiskt hydrauliskt år för att identifiera modellens styrparametrar. Den möjliga vattenöverföringen mellan de två dammarna orienterade modellutvecklingen mot en Mixed Integer Linear Programming (MILP) formulering. Efter att ha experimenterat med olika kalkylverktyg valdes Gurobi 28.1.0 för sin bra prestation i lösningen av Branch and Cut-algoritmen.  Systemets hydraulik har validerats genom att injicera realiserade produktionsplaner som input till modellen. Resultaten visar att volymfelet är mindre än 5% av deras respektive kapacitet under en 5-dagars tidshorisont. Efter tvärstester mot historiska data konstaterades det att den nya optimeringsstrategin resulterar i bättre genomsnittliga elpriser på varje kWh inmatad till nätet och högre intäkter för kraftverket. Resultaten visar också på vikten av korrekt ventilmanövrering i optimeringsstrategin.  Modellen körs i rimliga beräkningstider och redan används i den dagliga optimeringen av Coindre kraftverket, vilket sparar mycket tid. Specifika exempel på den optimerade prestandan och framtida förbättringar hittas i slutet av denna rapport.

‘Net Positive Water’ explores the capability of domestic architecture to combat the developing urban water problem. Urban intensification is contributing to the volatility of urban waters and the breakdown of the urban water cycle. Inhabitant water misuse and overconsumption is overwhelming aging municipal utilities, resulting in the decay of urban water quality. LEEDTM and The Living Building Challenge are recognized Green Building Guidelines prescribing sustainable site and building water standards. Case Studies of domestic Green Building projects will showcase water conservation to enable domestic water renewal. Net Zero Water Guidelines based on the Green Building Guidelines outline Potable and Non-Potable water use to achieve a sustainable volume of water demand at 70 litres per capita per day. Sustainable water practices are encouraged by utilizing domestic building systems to increase water value and water awareness. Time-of-Use and Choice-of-Use exposure for household water related tasks establish water savings through the use of best-performing water fixtures and appliances. Net Positive Water Guidelines will establish On-site and Building standards for sustainable harvesting and storage of water resources. Clean and Dirty water management will prescribe Passive design and Active mechanical processes to maintain best-available water quality in the urban domestic environment. Net Positive Water building typology will integrate urban inhabitation as a functional component of the urban water cycle to use, reuse, and renew water resources. The method will be tested using a Mid-rise Pilot project to deploy the necessary Passive and Active mechanisms to generate Net Positive Water quality through Net Zero Water sustainable water use. The pilot project is situated in Waterfront Toronto - The Lower Don Lands development to harness regional interests for water renewal and environmental revitalization.

‘Net Positive Water’ explores the capability of domestic architecture to combat the developing urban water problem. Urban intensification is contributing to the volatility of urban waters and the breakdown of the urban water cycle. Inhabitant water misuse and overconsumption is overwhelming aging municipal utilities, resulting in the decay of urban water quality. LEEDTM and The Living Building Challenge are recognized Green Building Guidelines prescribing sustainable site and building water standards. Case Studies of domestic Green Building projects will showcase water conservation to enable domestic water renewal. Net Zero Water Guidelines based on the Green Building Guidelines outline Potable and Non-Potable water use to achieve a sustainable volume of water demand at 70 litres per capita per day. Sustainable water practices are encouraged by utilizing domestic building systems to increase water value and water awareness. Time-of-Use and Choice-of-Use exposure for household water related tasks establish water savings through the use of best-performing water fixtures and appliances. Net Positive Water Guidelines will establish On-site and Building standards for sustainable harvesting and storage of water resources. Clean and Dirty water management will prescribe Passive design and Active mechanical processes to maintain best-available water quality in the urban domestic environment. Net Positive Water building typology will integrate urban inhabitation as a functional component of the urban water cycle to use, reuse, and renew water resources. The method will be tested using a Mid-rise Pilot project to deploy the necessary Passive and Active mechanisms to generate Net Positive Water quality through Net Zero Water sustainable water use. The pilot project is situated in Waterfront Toronto - The Lower Don Lands development to harness regional interests for water renewal and environmental revitalization.