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Rapid urbanization of cities includes common characteristics of high-density populations and large number of impervious surfaces. The high percentages of impervious surfaces like rooftops, roads and parking lots in dense cities would block the natural hydrological infiltration process and increasing flooding threats. The goal of this study is finding solutions for meeting the nonpotable water use demand by applying water harvesting while also creating open green spaces for residents in urban communities. The design thesis explored the level of benefits that can be achieved by harvesting water from impervious surfaces like rooftops to fulfill the need for water consumption, purification and green open spaces for social activities in residential high-rise condominiums (multi-family residences) in Wuhan, China. The study has compared hydrological and social benefits from 3 different design scenarios in the selected urban community: 1) the existing site design with underground parking, 2) a new design without underground parking which expands water harvesting options, and 3) a new design with underground parking which limits the application of some BMPs (Best Management Practices). This study used open space design and water harvesting as a strategy to meet 94% of non-potable water consumption by harvesting water from residential rooftops as well as to decrease and purify surface runoff to reduce the flooding threat from ground surfaces in the selected community. The proposed open space design also achieved social benefits of providing places for social interactions, supporting various recreational activities, educating children about environmental issues while having in outdoor activities, experiencing nature and keeping or improving the physical and mental well-being of people in the selected urban community. / Master of Landscape Architecture / Dense cities have the characteristics of having high-density impervious surfaces roads, bridges, rooftops as well as a large amount of population. Since a large amount of increasing population in dense cities would result in high demands for water consumption, the water shortage problem, as a global issue, has challenged the distribution of water resources in dense cities. The massive number of impervious surfaces, as a result of rapid urbanization, have blocked the process of hydrological circulation by making natural infiltration impossible. Therefore, many dense cities are facing the challenges of waterlogging or flooding threat and the decreasing amount of water resources. This study focuses on using open space design and water harvesting as a strategy to relieve the stress of limited water resources and waterlogging or flooding threat in dense cities. This thesis has chosen an urban community in Wuhan, China for making open space design and bring the hydrologic and social benefits to the selected urban community by combing the practices of water treatment into the design. The new open design in the selected community not only has the hydrological benefits of decreasing and purifying surface runoff to reduce flooding threat, but also has many social benefits such as providing places for social interactions, supporting various of recreational activities, educating children about environmental issues while participating in outdoor activities, experience nature and keeping or improving the physical and mental well-being of people.

Thesis (MSc. (Agricultural Economics)) -- University of Limpopo, 2011 / In-field rainwater harvesting technology is the technique that combines the advantages of water harvesting, no till, basin tillage and mulching on high drought risk clay soils. It reduces total runoff to zero, and also considerably reduce surface evaporation. The scarcity of agricultural water is increasing at a faster rate than for other sectors in Limpopo Province. Sufficient, clean drinking water is essential to life, but millions of people throughout the world including South Africa continue to have no access to this basic necessity. This study aimed at investigating the extent and nature of adoption of in-field rainwater harvesting technology by households in Lambani village of Limpopo Province. The main objectives of this study were to identify factors determining the in-field rainwater adoption technology for cropland productivity in Lambani village and to determine the extent to which in-field rainwater harvesting adoption influences cropland productivity in Lambani village. Simple random sampling technique was used to select 70 farmers in Lambani village of Limpopo Province. Data was collected using a structured questionnaire. Descriptive statistics, logistic regression model and linear regression model were used to analyse the data. Descriptive statistics was used to describe the characteristics of households and the nature of Lambani village, and logistic regression model was used to investigate factors that determine the adoption of infield rainwater harvesting technology, while linear regression model was used to determine the extent to which in-field rainwater harvesting influence the cropland productivity in Lambani village. The results from the logistic regression model indicate that 5 variables out of 10 variables are significant in explaining farmers’ adoption decision. Land size, access to financial service, access to information and contact with extension officer are some of the variables that have significantly positive effects on the adoption of infield rainwater harvesting technology, while hired labour has significantly negative correlation with adoption. Variables such as household size, level of education, age of the household, level of income and the main water source do not significantly influence adoption of in-field rainwater harvesting. This information will help prioritize

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The pervious pavement system has been identified as an effective source control device capable of removing urban stormwater pollution by trapping pollutants within the system and biodegradation. Recent studies have further demonstrated that the pervious pavement system could be used as a source of renewable energy capable of reducing household energy bill by about 80%. In view of ever increasing demand for water and the continued reduction in available fresh water resources in the world, stormwater has been recognized as a potential valuable source of water which could be harnessed. The overall aim of this multi disciplinary research was to evaluate the suitability of a modified pervious pavement system (PPS) for water harvesting and re-use, particularly focussing on potential third world applications and taking advantage of the latest developments in materials that are available for such applications. The aim was a holistic one in which water re-use was examined in terms of both the potential advantages from an irrigation point of view without ignoring the very important public health concerns that are often of concern when water is stored in circumstances which do not fit the normally used criteria for potable supplies. The results of this study confirmed the pollution control capability of the porous pavement system as earlier determined by previous studies. Also, a novel experimental rig was designed to reproducibly create very high and realistic rainfall events over model pavement structures. Furthermore, the performance of a new geotextile, Inbitex Composite® in the pervious pavement system was determined for the first time. Furthermore, this study also tested for the first time, the performance of a pervious pavement system modified by the incorporation of Inbitex Composite® geotextile with slits and made prescriptions as to how this new geotextile could be best installed in a modified pervious pavement system in order to achieve high infiltration without compromising pollution control. This study tested the practical use of the pervious pavement system for water harvesting and storage for reuse in irrigation. In order to achieve this, the author took what could be considered as a holistic approach to water quality issues and determined the chemical, electrochemical and microbiological quality of water stored in the system as well as investigated the public health concern of the potential of pathogenic organisms in waters stored in unconventional water storage system as the pervious pavement system. It also determined that the pervious pavement system have the capability to recycle water with physical, chemical and microbiological qualities that will meet international standards for irrigation and that the system does not offer a conducive environment for potential pathogenic organisms if contamination incident occurs from adjoining areas. This study also became the first to practically relate Sustainable Urban Drainage System (SUDS) to agricultural benefit by demonstrating how a SUDS device (pervious pavement system) could be used in addition to its urban drainage control role, as a source of supply of high quality irrigation water to cultivate crops fit for human and animal consumption despite high application of pollutants. This study determined contrary to the observation of earlier studies that the use of slow-release iv fertilizer could lead to eutrophication problems in cases where the water is channeled to natural water courses. Furthermore, active response of potential pathogenic bacteria to the presence of slow-release fertilizer was observed in this study. This raises a huge question on the need to add fertilizer to the pervious pavement system. Coupe, (2004) had demonstrated that oil degrading microbes would respond positively to food sources in the system and hence, there was no significant need for simulation by nutrient addition, the author concluded in the study presented here that fertilizer addition should only be conducted if the waters are to be used for irrigation where the nutrients would be beneficial to the plants and that even in this case, the microbiological water quality should be constantly monitored and the addition suspended if the risk of contamination from adjoining areas is high.

Water harvesting techniques were used for increasing water availability for rainfed agriculture and for human consumption. The treatments involving soil and water management for cropping were as follows: (1) traditional; (2) microcatchment; (3) microcatchment plus fertilization with ordinary superphosphate (OSP); (4) microcatchment plus fertilization with manure; and (5) supplemental tank irrigation. A cistern with 50 m³ capacity was constructed to provide drinking water. The crop enterprises were cowpeas (Vigna unguiculata)/corn (Zea mays), and sorghum (Sorghum bicolor)/cactus (Opuntia spp.)/algaroba (Prosopis juliflora). Both were intercropped. The overall objectives of the study were: (1) to examine the impact of the application of water harvesting techniques together with crop management, with and 14 without fertilization on: farmer, (ii) profitability cropping, and (iii) labor benefit of a cistern based (i) financial position of the of each individual enterprise in utilization; (2) to estimate the on the costs of carrying water. All analysis were developed with the aid of Supercalc 4 spreadsheet software. Farm performance measures were: crop production; cash flows; income statements, net worth; cost and returns statements; and labor utilization. The impact of the household cistern was assessed through a benefit cost approach. From the results the following main conclusions were drawn: (1) microcatchment contributed marginally to increased yields; (2) microcatchment combined with OSP produced yield increases which were twice those of the traditional process; (3) tank irrigation with OSP quadrupled the traditional productivities; (4) the sorghum/cactus/algaroba enterprise presented a better cash position than cowpeas/ corn; (5) the farm can support the investments necessary for the application of water harvesting since it is financially liquid and solvent; (6) significant increase in net income was achieved when water harvesting was combined with fertilization for both enterprises; (7) the existing family labor potential on the farm is enough to supply the demand imposed by any one of the soil and water management treatment; (8) if opportunity cost of labor is involved in assessing the profitability of cropping, the most profitable soil and water management practice was tank irrigation; and (9) the construction of a cistern is an economical and feasible decision.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Howard Hahn / Outdoor landscape irrigation is a prodigious consumer of potable water and accounts for more than 50% of urban water use in the United States. It is therefore imperative to reserve potable water for essential uses. The variability of recent drought trends coupled with the prediction of more intense, less frequent storms and rising water costs suggest the need to recycle as much free water as possible to meet non-essential irrigation demands. But is it possible to harvest enough water on-site to meet landscape water requirements with little to no reliance on municipal water? If not, how can design professionals adjust planting plans to bring the landscape water demand into equilibrium with potential supply while still meeting aesthetic objectives? This report uses predictive performance-based modeling to answer these questions. The author chose three study sites in St. Louis, Missouri to determine if the water demand of the existing landscapes can be supplied by collecting enough rainfall runoff and air conditioning condensate. Site selection depended on site size, differing harshness of localized environmental conditions, and ability to collect and generate large quantities of runoff and condensate water. Methods included a literature review, site inventory/analyses, estimation of plant water requirements using evapotranspiration data, estimation of rainfall runoff from various surfaces, and estimation of air conditioning condensate using thermodynamic equations. Findings show that landscape water needs for two of the three sites can be potentially met by on-site water sources with little to no reliance on municipal water. This was due to limited landscape areas compared to larger paved areas, the building footprint, and large quantities of air conditioning condensate produced during the hottest months. Under existing conditions, the third site was out of water balance. Consequently, the author undertook a planting re-design to convert low priority turf expanses to a naturalistic meadow requiring less water. Additionally, the author performed a return on investment analysis for both retrofit conditions and new construction. Overall, this research demonstrates that site-scale water harvesting for landscape irrigation purposes is a viable option to curtail reliance on municipal water supplies in the Midwest and similar climates.

Thesis (MSc. (Horticulture)) -- University of Limpopo, 2018 / Rainwater harvesting is an old age practice used in water-scarce rainfed crop production areas. It is practiced to supplement additional water for crops with insufficient amounts of rainfall for optimum production. The aim of this study was to assess yield responses of Swiss chard under In-field rainwater harvesting techniques (IRWH) and catchment areas. The trials were conducted at two sites, University of Limpopo experimental farm (Syferkuil) and on farmer’s field at Apel. The main plots were two catchment areas (2 m (1 m runoff strip plus 1 m basin)) and (3 m (2 m runoff strip plus 1 m basin)), while the subplots were five IRWH techniques namely; Control (farmers practice), Rainfed, IRHW (without mulch + irrigation), IRWH+Mulch and IRWH+Mulch+Irrigation. The results obtained showed no significant differences in yield of Swiss chard in relation to catchment areas of 3 and 2 m respectively. However, significant differences in plant height, plant vigour, number of leaves and chlorophyll contents were obtained under different IRWH techniques. Significantly, highest average plant height of 40.75 cm was obtained in IRWH+Mulch compared to Rainfed with the lowest average 28.50 cm at Syferkuil. A similar trend was obtained at Apel. There were significant differences in number of leaves under IRWH techniques; the highest mean of 16.00 was obtained in the control (farmers practice) treatment, while the lowest mean of 9.00 was obtained in IRWH treatment at Apel. At Syferkuil, significantly highest average number of leaves was obtained in the IRWH+Mulch+irrigation treatment, while the lowest average number of leaves was obtained in the rainfed treatment. Regarding the yield of Swiss chard, the significantly highest average yield was obtained under IRWH+Mulch+irrigation and 3 m catchment treatment combination which was 84.86 t ha-1 compared to 20.66 t ha-1 in rainfed and 3 m catchment treatment combination at Syferkuil. Similar trend was found at Apel with the highest average yield recorded in IRWH+Mulch+irrigation treatment combination. Hence, IRWH technique with mulch and irrigation could be adopted by growers in a water-scarce environment like the Limpopo Province of South Africa.

This bachelor thesis examines the pre-conditions for implementing a rain water harvesting system with additional purification on a school in a rural area of Cameroon. The villagers in this area are in general poor and lack basic access to water. The amount of rain in relation to the water need is thoroughly studied and two different UV purification are examined as potential systems for future use. The results showed that rain water harvesting is a suitable solution for the school if complemented by the further use of a natural spring nearby. The UV-systems are currently nearly non-existent on the Cameroonian market.

The limitation of urban water supplies is becoming worse each year. Several studies estimate that 2 billion of the world’s population will suffer from water scarcity by 2050; and urbanization rates is placing an even greater challenge in providing the infrastructure needed to serve growing populations. At this point, rainwater may be considered as the most critical, untapped water resource in a global aspect. Rainwater Harvesting Systems (RWHS) have tremendous potential, not only to provide sufficient water supply, but also to serve as a valuable stormwater management tool. Despite these benefits, RWHS is still not popular among ordinary people in urban situations, due mostly to high installation costs. This study aims to explore the equitable cost reallocation of residential rainwater harvesting systems between the urban utility, land developer and homebuilder, and individual homeowner sectors. It may be possible to redistribute the cost equitably among the parties based on potential benefits received,thereby making RWHS more affordable and more viable as a new water supply for urban areas. / text