Water Brief, Fourth Draft / 6.16.76 / Introduction: The need for an efficient method of storage of water in arid zones has long been recognized. Efforts have been made everywhere to develop small storage tanks to provide water at critical periods. However, most of the existing tanks have such annual or seasonal evaporation losses that they are equal or even greater than the average depth of the tank. Thus many of these tanks are completely depleted before the end of the dry season, often with dramatic consequences for human beings, livestock or agricultural activities depending on the water supply. Reducing the heavy evaporation and seepage losses in these tanks is an important way to increase the supply of water. Several methods have been developed to reduce these losses but one of the most effective ways is to make the tanks with a smaller surface but deeper. The importance of making tanks deeper has been recognized for many years but there are several constraints for achieving depth in tanks: (a) the gradient of the water stream, (b) the unsuitability of dozers to work in deep pits, and (c) shallow soils. However, these constraints can be removed by using high rise banks and water pumps. Efficiency can also be improved by keeping the water concentrated. With this idea in mind, Mr. Cluff, FAO Consultant, has developed the concept of the compartmented tank, which is being tried out successfully in Mexico, and whose main features are summarized below.

Project Completion Report, OWRT Project No. A-082-ARIZ / Agreement No. 14-34-0001-8003, Project Dates: October 1977-September 1978 / Acknowledgement: The work upon which this report is based was supported by funds provided by the United States Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1978. / This report contains the results of a one year study to apply the compartmented reservoir concept to water storage problems in Arizona. The range of selected projects was from a ten thousand cubic meter (8.1 af) reservoir for a water harvesting agrisystem at Black Mesa, to a 238 million cubic meter (200,000 af) flood control dam, Tat Momolikot Dam on the Papago Reservation, to supply water for irrigation. Other sites studied were the Santa Cruz River at Continental, to supply an industrial /domestic water, Leslie Creek site for recreation, and improvement of Mormon Lake for recreation. Evaporation from Tat Momolikot and Mormon Lake are presently consuming most of the available water. Through compartmentalization this evaporation can be significantly reduced. At the other potential dam sites on the Santa Cruz and Leslie Creek the use of a compartmented reservoir will make these otherwise marginal projects practical. The Black Mesa Agrisystem is presently demonstrating the utility of the compartmented reservoir system.

The aim of this study was to investigate the microbiological quality of drinking water at the source (taps at eThekwini laboratories, standpipes and mobile community tankers) and corresponding point-of-use (storage containers and ground tanks) supplied to peri-urban areas in Durban by eThekwini Municipality. It also aimed to identify factors associated with deterioration in water quality such as storage of water, household demographics, hygiene and sanitation practices. In order to determine the microbial quality of drinking water, the pour plate method (for enumeration of heterotrophic organisms) and the membrane filtration technique (for total coliforms and E. coli enumeration) were used. Conductivity, turbidity, pH and total and residual chlorine levels of drinking water were measured. Microbial and physico-chemical data was collated and statistically analysed with epidemiological data from an associated study to determine the link between microbial quality of drinking water, household demographics, health outcomes, socio-economic status, hygiene and sanitation practices. Findings showed that all point-of-use water was unsafe for human consumption as a result of either poor source water quality, in the case of standpipes, and microbial contamination at the point-of-use, in the case of ground tanks and community tankers. The latter could be attributed to unsanitary environments, poor hygiene practices or poor wateruse behaviour. Households which included children aged 0-5 years and in which open-top containers were used for water storage had the highest rates of diarrhoea and vomiting. Water from ground tanks had the best microbial quality but people in households using this water presented with the highest rate of diarrhoea. Therefore provision of microbially safe drinking water will not reduce the rate of health outcomes if addressed in isolation. In order to reduce water-associated illness, provision of safe and adequate amounts of water, hygiene and sanitation education and education on water-use behaviour should be provided as a package. The provision of improved water delivery systems does not ensure that drinking water is safe for human consumption. Measures, such as point-of-use water treatment should be considered to ensure that drinking water provided at the source and point-of-use is microbially safe for human consumption. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2009.

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The optimal reservoir operations problem consists of obtaining releases, storages of a reservoir and downstream reach routed flows such that benefits derived from operating the reservoir are maximized. These are obtained on the basis of forecasted inflows to the reservoir, and forecasted precipitation in the downstream reaches. Five goal programming schemes, namely (i) preemptive goal programming (ii) weighted goal programming (iii) minmax goal programming (iv) fuzzy goal programming and (v) interval goal programming are considered. The reservoir operation problem is also formulated as a multiobjective linear program (MOLP). It is shown that the optimal solutions of the goal programs are contained among the efficient points of the MOLP. It is also shown that the min max and fuzzy goal programs can yield inefficient points as optima; however, there exist alternate optima to these programs which are efficient. Therefore, it is suggested that one should solve an MOLP for considering alternative efficient solutions. These techniques are applied to the Green River basin system in Kentucky. / Master of Science

Thesis (M. Sc.) (Hons) -- University of Western Sydney, 2003. / "A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science (Hons.), University of Western Sydney, Australia, Water Research Laboratory, Centre for Water & Environmental Technology." Includes bibliography : leaves 168 - 183 and appendices.

MODRSP is program used for calculating drawdown, velocity, storage losses and capture response functions for multi - aquifer ground -water flow systems. Capture is defined as the sum of the increase in aquifer recharge and decrease in aquifer discharge as a result of an applied stress from pumping [Bredehoeft et al., 19821. The capture phenomena treated by MODRSP are stream- aquifer leakance, reduction of evapotranspiration losses, leakance from adjacent aquifers, flows to and from prescribed head boundaries and increases or decreases in natural recharge or discharge from head dependent boundaries. The response functions are independent of the magnitude of the stresses and are dependent on the type of partial differential equation, the boundary and initial conditions and the parameters thereof, and the spatial and temporal location of stresses. The aquifers modeled may have irregular -shaped areal boundaries and non -homogeneous transmissive and storage qualities. For regional aquifers, the stresses are generally pumpages from wells. The utility of response functions arises from their capacity to be embedded in management models. The management models consist of a mathematical expression of a criterion to measure preference, and sets of constraints which act to limit the preferred actions. The response functions are incorporated into constraints that couple the hydrologic system with the management system (Maddock, 1972). MODRSP is a modification of MODFLOW (McDonald and Harbaugh, 1984,1988). MODRSP uses many of the data input structures of MODFLOW, but there are major differences between the two programs. The differences are discussed in Chapters 4 and 5. An abbreviated theoretical development is presented in Chapter 2, a more complete theoretical development may be found in Maddock and Lacher (1991). The finite difference technique discussion presented in Chapter 3 is a synopsis of that covered more completely in McDonald and Harbaugh (1988). Subprogram organization is presented in Chapter 4 with the data requirements explained in Chapter 5. Chapter 6 contains three example applications of MODRSP.

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The design of a water supply system relies on the knowledge of the water demands of its specific end-users. It is also important to understand the end-users’ temporal variation in water demand. Failure of the system to provide the required volume of water at the required flow-rate is deemed a system failure. The system therefore needs to be designed with sufficient capacity to ensure that it is able to supply the required volume of water during the highest demand periods. In practice, bulk water supply systems do not have to cater for the high frequency, short duration high peak demand scenarios of the end-user, such as the peak hour or peak day events, as the impact of events is reduced by the provision of water storage capacity at the off-take from the bulk supply system. However, for peak demand scenarios with durations longer than an hour or a day, depending on the situation, the provision of sufficient storage capacity to reduce the impact on the bulk water system, becomes impractical and could lead to potential water quality issues during low demand periods. It is, therefore, a requirement that bulk water systems be designed to be able to meet the peak weekly or peak month end-user demands. These peak demand scenarios usually occur only during a certain portion of the year, generally concentrated in a two to three month period during the drier months. Existing design guidelines usually follow a deterministic design approach, whereby a suitable DPF is applied to the average annual daily system demand in order to determine the expected peak demand on the system. This DPF does not account for the potential variability in end-user demand profiles, or the impact that end-storage has on the required peak design factor of the bulk system. This study investigated the temporal variations of end-user demand on two bulk water supply systems. These systems are located in the winter rainfall region of the Western Cape province of South Africa. The data analysed was the monthly measured consumption figures of different end-users supplied from the two systems. The data-sets extended over 14 years of data. Actual monthly peak factors were extracted from this data and used in deterministic and probabilistic methods to determine the expected monthly peak factor for both the end-user and the system design. The probabilistic method made use of a Monte Carlo analysis, whereby the actual recorded monthly peak factor for each end-user per bulk system was used as an input into discrete probability functions. The Monte Carlo analysis executed 1 500 000 iterations in order to produce probability distributions of the monthly peak factors for each system. The deterministic and probabilistic results were compared to the actual monthly peak factors as calculated from the existing water use data, as well as against current DPFs as published in guidelines used in the industry. The study demonstrated that the deterministic method would overstate the expected peak system demand and result in an oversized system. The probabilistic method yielded good results and compared well with the actual monthly peak factors. It is thus deemed an appropriate tool to use to determine the required DPF of a bulk water system for a chosen reliability of supply. The study also indicated the DPFs proposed by current guidelines to be too low. The study identified a potential relationship between the average demand of an end-user and the expected maximum monthly peak factor, whereas in current guidelines peak factors are not indicated as being influenced by the end-user average demand. / AFRIKAANSE OPSOMMING: Die ontwerp van ‘n watervoorsiening stelsel berus op die kennis van die water aanvraag van sy spesifieke eindverbruikers. Dit is ook belangrik om ‘n begrip te hê van die tydelike variasie van die eindverbruiker se water-aanvraag. Indien die voorsieningstelsel nie in staat is om die benodigde volume water teen die verlangde vloeitempo te kan lewer nie, word dit beskou as ‘n faling. Die stelsel word dus ontwerp met voldoende kapasiteit wat dit sal in staat stel om die benodigde volume gedurende die hoogste aanvraag periodes te kan voorsien. In die praktyk hoef grootmaat water-voorsiening stelsels nie te voldoen aan spits watergebeurtenisse met hoë frekwensie en kort duurtes, soos piek-dag of piek-uur aanvraag nie, aangesien hierdie gebeurtenisse se impak op die grootmaat stelsel verminder word deur die voorsiening van wateropgaring fasiliteite by die aftap-punte vanaf die grootmaatstelsels. Nieteenstaande, vir piek-aanvraag gebeurtenisse met langer duurtes as ‘n uur of dag, raak die voorsiening van voldoende wateropgaring kapasiteit by die aftap-punt onprakties en kan dit selfs lei tot waterkwaliteits probleme. Dit is dus ‘n vereiste dat grootmaat watervoorsienings stelsels ontwerp moet word om die piek-week of piek-maand eindverbruiker aanvrae te kan voorsien. Hierdie piek-aanvraag gebeurtenisse vind algemeen in gekonsentreerde twee- of drie maand periodes tydens die droeër maande plaas. Bestaande ontwerpsriglyne volg gewoonlik ‘n deterministiese ontwerp benadering, deurdat ‘n voldoende ontwerp spits faktor toegepas word op die gemiddelde jaarlikse daaglikse stelsel aanvraag om sodoende te bepaal wat die verwagte spits aanvraag van die stelsel sal wees. Hierdie ontwerp spits faktor maak nie voorsiening vir die potensiële variasie in die eindverbruiker se aanvraag karakter of die impak van die beskikbare water-opgaring fasiliteit op die benodigde ontwerp spits faktor van die grootmaat-stelsel nie. Hierdie studie ondersoek die tydelike variasie van die eindverbruiker se aanvraag op twee grootmaat watervoorsiening stelsels. Die twee stelsels is geleë in die winter reënval streek van die Wes-Kaap provinsie van Suid-Afrika. Die data wat geanaliseer is was die maandelikse gemeterde verbruiksyfers van verskillende eindverbruikers voorsien deur die twee stelsels. Die datastelle het oor 14 jaar gestrek. Die ware maand piekfaktore is bereken vanaf die data en is in deterministiese en probabilistiese metodes gebruik om die verwagte eindverbruiker en stelsel ontwerp se maand spits-faktore te bereken. Die probabilistiese metode het gebruik gemaak van ‘n Monte Carlo analise metode, waardeur die ware gemeette maand spits-faktor vir elke eindverbruiker vir elke grootmaatstelsel gebruik is as invoer tot diskrete waarskynlikheids funksies. Die Monte Carlo analise het 1 500 000 iterasies voltooi om waarskynlikheids-verdelings van elke maand spitsfaktor vir elke stelsel te bereken. Die deterministiese en probabilistiese resultate is vergelyk met die ware maand spits faktore soos bereken vanuit die bestaande waterverbruik data, asook teen huidige gepubliseerde ontwerp spits-faktore, wat in die bedryf gebruik word. Die studie het aangetoon dat die deterministiese metode te konserwatief is en dat dit die verwagte piekaanvraag van die stelsel sal oorskat en dus sal lei tot ‘n oorgrootte stelsel. Die probabilistiese metode het goeie resultate opgelewer wat goed vergelyk met die ware maand piek-faktore. Dit word gereken as ‘n toepaslike metode om die benodigde ontwerp spits-faktor van ‘n grootmaat-watervoorsiening stelsel te bepaal vir ‘n gekose voorsieningsbetroubaarheid. Die studie het ook aangedui dat die ontwerps piek-faktore voorgestel deur die huidige riglyne te laag is en dat dit tot die falings van ‘n stelsel sal lei. Die studie het ‘n moontlike verwantskap tussen die gemiddelde daaglikse wateraanvraag van die eindverbruiker en die verwagte maksimum maand spits faktor geïdentifiseer, nademaal die piek-faktore soos voorgestel deur die huidige riglyne nie beïnvloed word deur die eindverbruiker se gemiddelde verbruik nie.

A disponibilidade de água no solo para as culturas é um dos principais fatores de produção. O estudo das características climáticas, juntamente com as propriedades físico-hídricas do solo, o sistema de manejo do agro-ambiente e as características vegetais são itens fundamentais para a implantação de um canavial produtivo. Objetivando caracterizar o comportamento da água no solo e sua influência na produtividade da cana-de-açúcar com e sem adubação nitrogenada, foram instalados instrumentos para medir a entrada e saída da água do solo, permitindo a efetuação do balanço de água em um LATOSSOLO VERMELHO Distrófico típico, localizado na Usina Santa Adélia, Município de Jaboticabal - São Paulo. O estudo foi conduzido em delineamento de blocos casualizados, com 2 tratamentos e 4 repetições, sendo que os tratamentos constaram de uma testemunha - T1 (sem adubação nitrogenada) e T2 (120 kg ha-1 de nitrogênio). As avaliações foram realizadas do dia 30 de setembro de 2005 a 12 de julho de 2006. O volume de controle de utilizado teve como limite inferior a profundidade de 0,90 m, uma vez que essa camada engloba mais de 95 % do sistema radicular da cana-de-açúcar. A precipitação pluviométrica foi medida com um pluviômetro, modelo Paulista, instalado ao lado da área experimental e uma estação meteorológica automática instalada a 500 m da área experimental. As armazenagens de água no solo foram feitas gravimetricamente, nas seguintes camadas: 0 - 0,15; 0,15 - 0,25; 0,25 - 0,35; 0,35 - 0,45; 0,45 - 0,55; 0,55 - 0,65; 0,65 - 0,75; 0,75 - 0,85; 0,85 - 0,95 m; em períodos que variaram de 14 a 28 dias, totalizando 14 amostragens. Para a determinação das densidades de fluxo diárias, no limite inferior do volume de controle de solo, foram instalados tensiômetros nas profundidades de 0,80; 0,90 e 1,0 m, sendo que o tensiômetro de 0,90 m foi utilizado para a estimação da umidade do solo, com uso da curva de retenção da água no solo, e os outros dois tensiômetros para o cálculo do gradiente de potencial total da água no solo. As densidades de fluxo foram calculadas pela equação de Darcy-Buckingham, sendo que a condutividade hidráulica do solo foi determinada pelo método do perfil instantâneo. Conhecendo esses componentes, foi possível efetuar o balanço de água no solo para os 13 períodos, calculando a evapotranspiração pela equação de balanço de massas, uma vez que a pequena declividade permitiu negligenciar o escoamento superficial. As perdas de água por drenagem interna para todo o período não apresentou diferença significativa, enquanto a entrada de água no volume de controle de solo por ascensão capilar foi 87,53 % maior no T2. Esse comportamento das densidades de fluxo nos tratamentos não refletiu em diferença significativa para a armazenagem de água no solo. Ao longo dos 13 períodos avaliados, o T2 apresentou uma evapotranspiração de 1156,06 mm, enquanto no T1 foi de 1057,85. Não se verificou diferença significativa para a produtividade, nem para a eficiência de uso da água da cultura. / The soil water availability for agricultural crops is one of the main production factors. The study of climatic characteristics together with soil physical and hydrological properties, agroenvironmental management system and the plant characteristics are of fundamental importance for the introduction of a productive sugarcane crop. With the objective of characterizing the soilwater behaviour and its influence on the sugarcane productivity, with and without nitrogen fertilization, instruments were installed to measure inputs and outputs of water in the soil, which permitted the determination of the water balance in an Ultisol (Arenic Kandiustults) located in the county of Jaboticabal, State of São Paulo, Brazil. The work was carried out using the experimental design of random blocks, with two treatments and four replications, being the treatments: T1 (control, without nitrogen fertilization), T2 (120 kg ha-1 of nitrogen fertilization). Measurements were made from September 30, 2005 to July 12, 2006. The lower limit of the soil control volume for the water balance was the soil depth if 0.9 m. Rainfall was measured with a raingauge, model ?Paulista? installed beside the experimental area and also by means of an automatic meteorological station installed 500 m from the experimental area. Soil water storages were made gravimetrically in the following soil layers 0 - 0.15 m; 0.15 - 0.25 m; 0.25 - 0.35 m; 0.35 - 0.45 m; 0.45 - 0.55 m; 0.55 - 0.65 m; 0.65 - 0.75 m; 0.75 - 0.85 m; 0.85 - 0.95 m in periods that varied from 14 to 28 days, totalizing 14 samplings. For the dayly water flux density calculations in the lower limit of the control volume, by Darcy-Buckingham equation, tensiometers were installed the 0.80, 0.90 and 1.00 m soil depths, being the tensiometer at the 0.90 m depth used to calculate the soil water content, via a soil water retention curve, and then the soil hydraulic conductivity at this depth, and the other two tensiometers to calculate the soil water total potential gradient at the same depth. The hydraulic conductivity as a function of soil water content was determined by the instantaneous profile method. With the knowledge of these processes of the soil water balance, it was possible to determine the balance for the 13 selected periods, calculating the actual evapotranspiration as the unknown of the soil water balance equation. The small slope of the experimental area permitted to neglect the surface runoff. Internal drainage water losses for the entire period between treatments, were not different, while the water inputs in the control volume by capillary rise was 87.53% higher in treatments T2. This behaviour of the water flux densities in the treatments did not reflect in significant differences for the soil water storage. For the entire evaluated period, treatment T2 presented an evapotranspiration of 1156.06 mm, and treatement T1 of 1057.85 mm. Sugarcane productivity and water use efficiency did not present significant defference between treatments T1 and T2 eventhough plants of treatment T1 were, in average, more efficient in using water.

O estabelecimento de balanços hídricos no campo é difícil e dispendioso, sendo a variabilidade de seus componentes o maior problema para se obter resultados confiáveis. Esta variabilidade dos componentes é aqui apresentada para uma cultura de café desenvolvida no hemisfério sul, em um solo tropical com 10% de declividade. É concluído que a chuva deve ser medida com um número apropriado de repetições, que a irrigação pode introduzir grande variabilidade dos cálculos, que a evapotranspiração calculada a partir da equação do balanço hídrico tem coeficientes de variação muito altos, que o componente armazenamento de água no solo é o que mais contribui na propagação dos erros e que a enxurrada pôde ser satisfatoriamente controlada nesse declive por meio de práticas de manejo. / The establishment of field water balances is difficult and costly, the variability of its components being the major problem to obtain reliable results. This component variability is here presented for a coffee crop grown in the Southern Hemisphere, on a tropical soil with 10% slope. It is concluded that rainfall has to the measured with an appropriate number of replicates, that irrigation can introduce great variability into calculations, that evapotranspiration calculated from the water balance equation has high coefficients of variation, that the soil water storage component is the major contributor in error propagation calculations, and that the run-off could be satisfactorily controlled through crop management practices.