Performance Evaluation of Inverted Umbrella Type Rainwater Harvesting System at Raichur Campus

The Inverted Umbrella-Type Rainwater Harvesting System is an innovative approach to collecting and storing rainwater efficiently. It is designed in the shape of an inverted umbrella, with a lightweight and durable frame that can be installed on rooftops, open fields, and urban landscapes. This unique design was used with a aim to maximizes rainwater collection efficiency, even during light showers, while occupying minimal space. The system's adaptability to various geographic and climatic conditions makes it a versatile solution for addressing water scarcity. It has potential applications in residential, commercial, and industrial settings, contributing to more responsible water resource management. Rainfall data was collected from meteorological station at Raichur and potential for rainwater harvesting was calculated. Developed rainwater harvesting system was made out of Mild Steel material and transparent white polyethylene sheet was used as cladding material.. The Inverted Umbrella-Type Rainwater Harvesting System represents a promising step toward more responsible water resource management. The Inverted Umbrella-Type Rainwater Harvesting System of size 3m*3m was selected in the study to analyze rain water harvesting efficiency with components like canopy, central conveying pipe, storage tank, filteration mechanism etc. Once the rain falls over the canopy it was diverted to a central connecting pipe and then stored in a storage tank. A co-efficient of performance for kharif season during the year 2022 was developed to estimate the efficiency of the system. Annually 5700 litres of water can be harvested from a single unit of inverted umbrella type rainwater harvesting system. Anticipated and actual water yield during kharif season was found as 4627.56 and 4480.5 L respectively with overall efficiency as 97%. Key features of this system include high collection efficiency, a small footprint, environmental sustainability, ease of maintenance, and water quality assurance. It reduces reliance on traditional water sources, helping conserve water and mitigate environmental impacts

Hydrological Investigations in Red Soils of a Micro Catchment Area for Dugout Farm Pond at UAS Raichur Campus

Aims: To measure and characterize storm wise runoff for the catchment area of the farm pond and to correlate rainfall intensity and runoff relationship for the catchment area will help to design the appropriate size of the farm pond and waste weirs of the bunding system. Place and Duration of Study: The study was conducted in a micro catchment (field sized area) of a dugout farm pond, having an area of 6 ha located in the new area of UAS campus Raichur, which comes under Zone II in Region-I of Karnataka state. Geographically it is located at 16° 12? N latitude and 77° 20? E longitude and at an elevation of 389 m above the mean sea level (MSL). The study was conducted for a period of one year during 2019. Methodology: The existing farm pond constructed was used for conducting hydrological studies. The detailed soil and rainfall characterization of the study area has been made through appropriate methods. The rainfall intensity for each storm has been measured using self-recording rain gauge. The runoff has been measured at the out let of the field sized micro catchment area of farm pond using hydraulic structures coupled with automatic runoff recorder. The event wise rainfall, rainfall intensity and runoff have been measured and analysed to see the relationship between rainfall intensity and runoff with prevailing soil and topographical characteristics of the study area. Results: The percent runoff varied from 6.79 to 50.42 and highest was 50.42 per cent occurred on 25-10-2019 followed by 44.03, 39.36 and 37.46 per cent. The data shows that the individual storm wise percent runoff was quite high as compared to annual percent runoff of 15.99 per cent. The storm wise high runoff percent was due to the fact that high intensity of rainfall followed by high AMC in the soil. Further the minimum runoff yield of 142.66 m3 was observed on 18-07-2019 against the rainfall of 35.00 mm and maximum of 2985.48 m3 was yielded on 25-09-2109 against rainfall of 113.00 mm and followed by 1086.64 m3, 944.24 m3, 665.61 m3 and 431.25 m3 against rainfall of 46.00 mm, 42.00 mm, 22.00 mm and 48.00 mm respectively. The total annual runoff yield was found to be 6255.90 m3 against the rainfall of 651.50 mm. Therefore, there is a scope for harvesting excess quantity of runoff which is going as a waste. The existing pond capacity of 547.77 m3 is insufficient to store prevailing runoff generated in the catchment area and hence, pond capacity may be enhanced. The maximum intensity of rainfall and runoff during six events were showed statistically insignificant relationship with R2 value of 0.370. There is no correlation between intensity of rainfall and runoff.

Rainwater Harvesting through Point Recharge Method for Efficient Recharge of Tube Wells for Sustainable Management of Groundwater Resources in Karnataka

Water is a precious natural resource for sustaining life, agriculture and environment. The dependability on groundwater has reached high in all time in recent decades due to reasons such as unreliable supplies from surface water due to vagaries of monsoon, increase in demand for domestic, agricultural and other purposes. Karnataka is largely dependent on groundwater to meet industrial, municipal, domestic and irrigation needs. So, Rainwater harvesting (RWH) forms an important component for development and management of water resources for domestic, agricultural, municipal and industrial uses. Management of scanty rain fall by rain water harvesting, Augmentation of depleting natural resources of water (deeper ground water table) and Management of poor-quality ground water and scope for conjunctive/domestic use is need of the hour. With increase in withdrawal of ground water, ground water (GW) table is declining at a rapid pace with an urgent need to recharge GW in addition to dilute poor quality ground water. Double ring technique of Groundwater Recharge consists of filtering the water at different layers using gradation materials generally the pebbles of different size with synthetic material wrapped around the casing pipe. By harvesting rain water and recharging into point recharge soaking infiltration gallery established at Irrigation Water Management Research Centre, (IWMRC) Belavatagi Tq: Navalagund has shown encouraging results as far as water quality, discharge and water table are concerned. The results of assessment of influence of ground water recharge through rainwater harvesting on ground water yield (lps), quality (dS/m) and fluctuations (feet bgl) during the year 2020, have shown that around 3.35 lakhs liters of water could be collected from rain water harvesting during the year 2020. Also, from point recharge through 7 recharge events (rain fall events from July to October 2020), it was observed that the considerable rise in the water table from more than 100 feet below ground level to around 22 feet below ground level, drastic reduction in groundwater salinity i.e. electrical conductivity (EC) of ground water from more than 10 dS/m to an average (EC) of 1.32 dS/m and tube well yield has significantly increased from 0.4 lps to around 2.4 lps. Therefore, Artificial recharge techniques through rainwater harvesting can be a better strategic approach to combat the emerging problems of water scarcity especially over exploitation of ground water and its quality deterioration.

Aproveitamento de água pluvial e sua relação com ações de conservação de água: estudo de caso em hospital universitário, São Carlos (SP) / Rainwater harvesting and its relationship with water conservation actions: case study in a universitary hospital, São Carlos, São Paulo, Brazil

RESUMO A implantação de sistemas de aproveitamento de águas pluviais (SAAPs) em edificações com alto consumo de água, como estabelecimentos hospitalares, pode trazer benefícios tanto econômicos aos usuários como ambientais. No entanto, é considerada por alguns como a última ação a implementar na conservação da água nessas instituições, recomendando-se, em um primeiro momento, ações de diminuição de consumo. Por isso, este trabalho teve como objetivo avaliar o potencial de economia de água decorrente da implantação de um SAAP como alternativa de abastecimento de água e estabelecer comparações com ações de diminuição de consumo, tendo como objeto de estudo o Hospital Universitário (HU), da Universidade Federal de São Carlos, São Paulo. Para tanto, foi adotada uma metodologia baseada no balanço hídrico em função das demandas de água para diferentes usos no HU e em relação às edificações atualmente em funcionamento e ampliações futuras, previstas em dos fases; análises do tamanho ótimo de armazenamento e avaliação da redução de consumo com um maior controle das perdas e a substituição de tecnologias existentes por dispositivos economizadores nos mesmos períodos. Com a determinação da relação oferta-demanda, a implantação do SAAP evidenciou um potencial de economia de água de 57% do consumo com as instalações atualmente em funcionamento e de 19% do consumo final projetado para o final das ampliações, enquanto as ações de diminuição apontaram valores de 37 a 24% para os mesmos cenários. Procedimentos combinados de aproveitamento de águas de chuva e diminuição de consumo de água podem economizar entre 71% do consumo atual e 39% no final de projeto, níveis considerados significativos e que refletem a necessidade do gerenciamento estratégico da água que promovam benefícios financeiros, ambientais e sociais.

ABSTRACT The implementation of rainwater harvesting systems (RWHS) in buildings with significant water consumption, such as hospitals, can bring both economic and environmental benefits to users. However, it is considered by some the last action to be implemented in the conservation of water in these institutions, recommending at a first moment actions to reduce consumption. That is why the purpose of this study was to evaluate the potential of water saving by means of the implementation of a RWHS as an alternative of water supply and to establish comparisons with water uses conservations actions, having as an object of study the University Hospital of the Federal University of São Carlos - SP (UH). This was determined by a methodology based on the water balance as a function of the water demands for different uses in the UH and in relation to the buildings currently in operation and future extensions, planned in the phases; optimal storage size analysis and consumption reduction assessment with greater loss control and replacement of existing technologies with cost-saving devices over the same periods. With the determination of the supply - demand relationship, RWHS's implementation showed a water saving potential of 57% of the current consumption and 19% of the projected end, while the decreasing actions indicated values of 37 to 24% for the same scenarios. Combined actions for rainwater harvesting and reducing water consumption can save between 71% of current consumption and 39% at the end of the project, which are considered to be significant levels and reflect the needs of strategic water management with financial, environmental and social benefits.

Análise dos métodos de dimensionamento de reservatórios de águas pluviais sugeridos pela NBR 15527/07 com base na simulação diária / Analysis of the rainwater tank sizing methods suggested by NBR 15527/07 through daily simulation

RESUMO A fim de superar o problema de disponibilidade de água e preservar os recursos hídricos, têm sido buscadas fontes alternativas de água para satisfazer as atividades humanas. Entre as soluções encontradas, está a captação da água de chuva. Essa técnica é possível através da captação da precipitação em áreas impermeáveis e de seu armazenamento em reservatórios para viabilizar seu uso. O reservatório é, em geral, a parte mais dispendiosa da implantação desse sistema. O dimensionamento dessa estrutura pode ser realizado através de diferentes métodos, por isso, é necessário avaliar qual deles é o mais adequado. Para tanto, este trabalho analisou os métodos de dimensionamento de reservatórios sugeridos pela Associação Brasileira de Normas Técnicas (ABNT), apresentados na norma NBR 15527/07, em relação aos seus desempenhos. A análise foi feita com base nos níveis de garantia de abastecimento alcançados de acordo com o método utilizado. A partir dos resultados obtidos, foi constatado que os métodos Rippl Diário e Mensal se destacam por gerarem reservatórios associados a garantias de abastecimento elevadas (entre 98 e 100%).

ABSTRACT To overcome the problem of water availability and to preserve water resources, there have been sought alternative sources of water to supply human activities. Among the available solutions, there is rainwater harvesting. This technique is based on capturing rainfall from impermeable areas and storing it in tanks to enable its use. The tank is, usually, the most expensive part of such a system. This structure design is possible through different methods, hence the need to evaluate which of those is the most appropriate one. Therefore, this paper analyzed the sizing methods suggested by the Brazilian Association of Technical Standards (Associação Brasileira de Normas Técnicas - ABNT), presented in the technical standard NBR 15527/07, concerning their performance levels. The analysis was based on the guarantee levels of supply achieved according to the method used. From the results obtained, the Daily and Monthly Rippl methods for producing tank capacities associated with the higher supply reliability (98 to 100%).

SIMCAP: ferramenta computacional para auxiliar a tomada de decisão sobre a implantação de sistemas de captação de águas pluviais / SIMCAP: computational tool to assist decision-making on the implementation of rainwater harvesting systems

RESUMO Uma das soluções encontradas para superar o problema de disponibilidade de água e preservar os recursos hídricos é o uso de água pluvial. Isso é possível por meio da captação da precipitação em áreas impermeáveis e de seu armazenamento em reservatórios que viabilizem seu uso. Essa nota técnica apresenta uma ferramenta eletrônica denominada SIMCAP, que auxilia na tomada de decisão em relação ao volume de uma cisterna a ser implantada em edificações de municípios do estado de São Paulo. Para utilizar a ferramenta é necessário fornecer: um volume de reservatório, o município onde o sistema será instalado, a categoria da edificação e a demanda de água pluvial. A ferramenta traz como resultados informações técnicas relativas ao volume de reservatório sugerido pelo usuário quanto à garantia de abastecimento, além da economia de água e financeira que resultam da implantação do sistema.

ABSTRACT One of the possible solutions to overcome the problem of availability of water and to preserve water resources is the rainwater use. This technique consists on capturing rainfall in impermeable areas and storing it in reservoirs to enable its use. This technical note presents an electronic tool, named SIMCAP, created to assist decision-making concerning the volumes of reservoirs implanted in buildings of towns of the state of São Paulo, Brazil. Therefore, the tool requires: a reservoir capacity suggestion, the municipality the system will be implemented, the building category and the rainwater demand. The tool brings results regarding the technical information about the volume of reservoir suggested by the user as guarantee of rainwater supply, water and economical savings resulted from the system.

Influência da intensidade de precipitação na geração de escoamento em telhados cerâmicos: experimentos em laboratório sob chuva simulada / Influence of rainfall intensity on the production of runoff on ceramic tile roofs: laboratory experiments under simulated rainfall

RESUMO Os sistemas de aproveitamento de água de chuva baseiam-se na coleta do escoamento de superfícies pouco permeáveis, como telhados e ruas. Esses sistemas são projetados, muitas vezes, com dados de pluviômetros, e não de pluviógrafos, e podem desconsiderar informações importantes da quantidade precipitada disponível para aproveitamento. Neste trabalho foram realizados experimentos em laboratório com simulação de chuvas de baixa, moderada e forte intensidades sobre um telhado cerâmico. As análises indicam que chuvas com intensidade entre 12,8 e 61,6 mm h-1 (moderada a forte) resultam em coeficiente de escoamento superior a 0,9, enquanto em chuvas com baixa intensidade (inferior a 1,2 mm h-1), o coeficiente de escoamento diminui drasticamente, aproximando-se a 0 para intensidades próximas a 0,25 mm h-1. Conclui-se que, para as condições dos experimentos realizados, a absorção de telhas cerâmicas influencia mais na redução do escoamento superficial para chuvas de baixa intensidade do que para chuvas de intensidade moderada ou forte.

ABSTRACT Rainwater harvesting consists on the collection of runoff from low permeable surfaces, as roofs and streets. Designing these systems is often based on pluviometer data and not on pluviograph data, therefore they do not consider crucial data on the amount of rainwater available to harvesting. Laboratory experiments were conducted by simulating low, moderate and high intensity rainfall on a ceramic tile roof. Results shown that rainfall intensities between 12.8 and 61.6 mm h-1 (moderate to high intensity) lead to runoff coefficients greater than 0.9, while for rainfall low intensities (lower than 1.2 mm h-1), the runoff coefficient drastically decreased, reaching values of zero for rainfall intensities lower than 0.25 mm h-1. In conclusion, for the simulated experimental conditions, water absorption of the ceramic tiles is more significant on the runoff for very low rainfall intensities than the strong or moderate rainfall intensities.

MÉTODO DE DIMENSIONAMIENTO PARA TANQUES DE CAPTACIÓN DE AGUA LLUVIA UTILIZANDO SERIES DE RESOLUCIÓN DIARIA DE LLUVIA Y DE DEMANDA DE AGUA / SIZING METHOD FOR STORMWATER HARVESTING TANKS USING DAILY RESOLUTION RAINFALL AND WATER DEMAND DATA SETS

This work presents a simplified method for rainwater harvesting (RWH) tank sizing using long day-resolution rainfall time series. This method considers heterogeneous contributing catchments and water demand flow rates. For the tank sizing, we proposed to take into account the probability to supply the water demand, as well as the most needed probable time step and their respective variabilities. The method was applied to a specific case study (Pontificia Universidad Javeriana, RHW project), with 73 years of daily-resolution rainfall information (between 1936-2010). For the analysis we used different time periods from data-set and the results were: (i) for the whole data-set 76 years: 395 m3 (28 days, probability: 78%); (ii) for the last ten years: 494 m3 (35 days, probability: 89%); (iii) for the last five years: 346 m3 (25 days, probability: 84%); (iv) for the last year: 155-198 m3 (11-14 days, probability: 89-90%). These results seem to be influenced by an evolution of rainfall depth in different selected periods, which will be studied in further researches.

Este trabajo presenta un método simplificado para el dimensionamiento de tanques de aprovechamiento de aguas lluvias (AAL). Este método considera cuencas tributarias heterogéneas y caudales de demanda de agua. Se propone tener en cuenta la probabilidad para suministrar la demanda de agua, así como el paso de tiempo necesario de recolección más probable y sus respectivas variabilidades. El método se aplicó a un estudio específico de caso (Pontificia Universidad Javeriana, proyecto AAL), con 73 años de información de precipitación a resolución diaria (entre 1936-2010). Para el análisis se utilizaron diferentes períodos de tiempo, los volúmenes del tanque con el tiempo de recolección fueron los siguientes: (i) para el conjunto entero de datos 76 años: 395 m3 (28 días, probabilidad: 78%); (ii) para los últimos diez años: 494 m3 (35 días, probabilidad: 89%); (iii) para los últimos cinco años: 346 m3 (25 días, probabilidad: 84%); (iv) para el último año: 155 a 198 m3 (11 a 14 días, probabilidad: 89-90%). Estos resultados parecen estar influenciados por una evolución de la altura de lluvia en los diferentes períodos seleccionados, lo cual será estudiado en investigaciones posteriores

Acesso à água proporcionado pelo Programa de Formação e Mobilização Social para Convivência com o Semiárido: Um Milhão de Cisternas Rurais: combate à seca ou ruptura da vulnerabilidade? / Access to water provided by the Training and Social Mobilization Program for Coexistence with the Semi-Arid - One Million Cisterns Program: combating drought or rupture of the vulnerability?

RESUMO Está em curso no Brasil um dos maiores programas mundiais de aproveitamento de água de chuva para consumo humano: o Programa de Formação e Mobilização Social para Convivência com o Semiárido: Um Milhão de Cisternas Rurais (P1MC). Neste artigo, avalia-se o P1MC a partir do ponto de vista dos seus usuários. O marco empírico é composto por trabalho de campo que, entre fevereiro de 2009 e julho de 2011, envolveu a realização de um survey, com aplicação de 623 questionários em 63 municípios alcançados pelo programa no semiárido do estado de Minas Gerais, realização de 32 entrevistas semiestruturadas com gestores e técnicos envolvidos nos processos e de 15 entrevistas semiestruturadas com a população atingida. Foram também utilizadas técnicas de observação, bem como avaliação por meio de fotografias das cisternas implantadas. Os resultados indicam que a presença dos sistemas de aproveitamento de água de chuva reduziu em quase 90% o total de tempo despendido na busca de água. No entanto, existem problemas relacionados à qualidade e à quantidade de água disponibilizada. Evidenciou-se ainda a persistência de elevada precariedade das condições socioeconômicas, sendo esse um fator limitante para o alcance da efetividade do programa. Observou-se que o programa tem atingido suas metas de construção das estruturas físicas, mas que ainda são significativos os desafios, especialmente os relacionados à oferta adequada de água em quantidade e qualidade. Sendo assim, é necessário que as políticas públicas de abastecimento de água no espaço rural semiárido associem questões técnicas com elementos de gestão considerando as especificidades sociais, climáticas e econômicas locais.

ABSTRACT Program of Training and Social Mobilization for Living with the Semiarid: One Million Rural Cisterns (P1MC), one of the largest programs of rainwater harvesting for human water supply, is underway in Brazil. This article presents an assessment of the P1MC, from the point of view of users. The methodology was based on a survey with 623 interviews in 63 municipalities reached by the programme, in-depth interviews with 32 managers and technicians and 15 users, participant and non-participant observations and image recording. Field works were carried out between February 2009 and July 2011. The results indicate that the presence of rainwater harvesting systems reduced by almost 90% the total time spent in search of water. Results also showed that highly precarious socioeconomic conditions still prevail, which is a limiting factor for the achievement of program effectiveness. The program has achieved its goal of building physical structures, but there are still significant challenges, especially those related to adequate supply of water in quantity and quality. Therefore, public policies for water supply in semiarid rural areas should associate technical issues with management elements considering the social, climatic and economic local conditions.

Rainwater as a Domestic Water Supplement in Scotland: Attitudes and Perceptions.

Aims: Water resources in Scotland are under immense pressure despite the perception that Scotland enjoys abundant rainfall and water resources. The transport and treatment of water utilizes high amounts of energy is which contradicts the UK government’s carbon neutral agenda. There is also the need to ensure reliable water supply to households whilst protecting the natural environment. The intent of this study therefore was aimed to explore the feasibility of rainwater harvesting (RWH) as a domestic water supplement in some selected peri-urban areas in Scotland by understanding people’s perceptions, attitudes and behaviour towards RWH systems; and the preference for a community or individual system. Methodology: Paper questionnaires were administered randomly to households using Private Water Supply (PWS) in three local areas: Highlands, Scottish Borders and Aberdeenshire over a period of 4 months. Results: The response rates for Highlands, Scottish Borders and Aberdeenshire were 28%, 27% and 19% respectively, with the latter being marginally below target. The survey responses revealed that participants were unlikely to use RWH for domestic purposes including drinking, bathing, dishes and laundry but felt RWH would be acceptable for most uses except drinking. These included non-potable uses such as gardening, car washing and toilet flushing. Conclusion: Most respondents were indifferent to implement RWH in their house if their neighbor used it or if it was a community set-up, but were willing to consider it if grant incentives were offered.

Diagnóstico del sistema de aprovechamiento del agua lluvia en el consejo comunitario de la comunidad negra de los lagos, buenaventura / Diagnostic system rain water harvesting in the black community council community of lagos, buenaventura

Este trabajo presenta los resultados de la investigación realizada en el Consejo Comunitario de la Comunidad Negra Los Lagos (CCCN Los Lagos); la cual consistió en diagnosticar las condiciones de aprovechamiento del agua lluvia, por lo que se pudo determinar el potencial de aprovechamiento del agua lluvia en la comunidad, los tipos de techos que utilizan las viviendas, el sistema de recolección y conducción del agua lluvia, los tipos de recipientes para realizar el almacenamiento del agua lluvia. Para la identificación de los aspectos anteriores, se realizaron visitas al lugar, así como también la realización de entrevistas semiestructuradas y encuestas (anexo 1). Luego de conocer el sistema de abastecimiento del agua lluvia, se realizó análisis fisicoquímicos y microbiológicos al agua lluvia recolectada, permitiendo conocer con ello el cumplimiento o no de la normativa ambiental; además, se aplicaron análisis estadísticos para determinar correlaciones y varianzas en los resultados.

This paper presents the results of research conducted at the Community Council of the black community of Los Lagos, which was to diagnose the conditions of use of rain water, so they could determine the potential use of rain water in the community, the types of roofs used housing, the system of collection and conveyance of rain water, types of containers for storage of rain water; for the identification of the above aspects, site visits were conducted, as well as semi-structured interviews and surveys. After meeting the supply system of rain water, chemical and microbiological to rain water collected analyzes were performed, thus allowing to know or not compliance with environmental regulations; Additional statistical analyzes were applied to determine correlations and variances in the results.

Monitoring Drainage Water Quality during Green Roof Irrigation Trials Using Synthetic Greywater.

Aims: To evaluate the potential for substituting green roof mains water irrigation by irrigation using lightly loaded synthetic greywater. Study Design: The planted green roof system was designed to be operated and tested within a glasshouse. Place and Duration of Study: Schools of Engineering, and Plant Sciences, The University of Reading, for 28 days commencing 28th of May 2012. Methodology: A trial was conducted for comparing two planting schemes using Sedum and Stachys Byzantina and a third unplanted control. The three sets of growing boxes were subdivided between substrate depths of 10 cm and 20 cm. By further subdivision, half of each set were watered using mains water, and half using a synthetic greywater. The soil composition and water quality of the drainage (filtrate) water were monitored. Statistical analysis of the results was conducted. Results: Consistency was observed in influent pH and EC, in both mains and greywater samples. Influent Na concentrations were higher in the greywater samples due to detergent content. The Na mass balance calculations for all boxes showed that some Na mass was unaccounted for when comparing aggregated concentrations in influent, plant tissue and soil with the aggregated Na mass in filtrate, plant tissue and soil water. It was concluded that this was likely to be due to retained/ponded irrigation water in the boxes, difficulties in attaining homogenous box flushing and the underestimation of soil Na. The variation in substrate depth affected all results. The plants themselves seemed to have little significant influence on the measured parameters, with the exception of the accumulation of Na mass in plants irrigated with greywater. Conclusion: No improvement was observed in the quality of the greywater following filtration through the soil matrix. For longer term watering using greywater, a choice of Na resistant species should be considered, although the Sedum species used in this trial showed no recorded adverse growth effects due to Na accumulation.

A Laboratory Study into a Novel, Retrofittable Rainwater Harvesting System.

Aims: To establish the system characteristics of a novel rainwater harvesting system. Study Design: A laboratory test rig was used to assess the selected technology. Place and Duration of Study: University of Exeter, Centre for Water Systems between June 2014 and May 2015. Methodology: Previous research has identified that systems should have: 1) reduced capital costs, 2) reduced operational costs and 3) increased ease of retrofitting. To investigate the system’s ability to address these requirements, two full-scale laboratory test rigs have been used to assess flow and power consumption characteristics under a range of installation scenarios. Results: The system was identified to have a mean power consumption of 0.12kWh/m3 during a one hour pump test. Electrical costs were found to increase when the power consumption of the 11W control board was taken into account. Conclusion: Subject to reduction of the standby power consumption of the controller, the novel RWH system assessed in this study has potential to provide non-potable water supplies to households in the UK at a lower power consumption rate than existing water supply systems identified in the literature.

Exploratory Assessment of SUDS Feasibility in Nhieu Loc-Thi Nghe Basin, Ho Chi Minh City Vietnam.

Aims: In recent decades, Ho Chi Minh City, Vietnam, frequently has been affected by local floods and inundation from heavy rainfall. Conventional flood mitigation measures such as building flood gates and upgrading sewerage systems have been implemented but problems persist. The objective of this research is to assess another approach for flood control measures, namely Sustainable Urban Drainage Systems (SUDS), with application to the Nhieu Loc - Thi Nghe Basin, located in the central part of Ho Chi Minh City. Methodology: A combination of the Stormwater Management Model (PCSWMM) and interviews with 140 households was used to assess the efficacy and acceptability of four of the most popular SUDS: Rainwater harvesting, green roofs, urban green space and pervious pavement. Thirteen SUDS and urban build-out scenarios were simulated under 6 design storm conditions. Results: PCSWMM results showed that inundation from intense rainfall could be reduced with proper land-use control, specifically by maintaining imperviousness at 65% or less of the surface area. With respect to SUDS performance, green roofs were best at reducing peak runoff (22% reduction), followed by pervious pavement, urban green space, and rainwater harvesting systems. Regarding environmental improvements, as represented by reduction in total suspended solids load, urban green space was best with 20% of the solids load removed compared to the base case scenario, followed by green roofs, pervious pavement, and rainwater harvesting. The household interviews revealed the majority of people preferred pervious pavement to the other SUDS options and the least preferred option was green roof technology. Conclusion: Considering the combination of water quantity and water quality controls, it seems that green roof technology was the best performer for this area of Ho Chi Minh City, followed by urban green space, pervious pavement and rainwater harvesting. However, green roof technology also was the least favored option for the public and stakeholder acceptance will impact SUDS implementation.

Qualidade de investimentos no uso de água pluvial: Particles Swarm Optimization para a maximização do valor presente líquido / Quality of investments in rainwater harvesting systems: Particles Swarm Optimization for maximization of net present value

A análise da qualidade dos investimentos deve fazer parte da tomada de decisão pela implantação dos sistemas de aproveitamento de água pluvial, de modo a avaliar se os investimentos na redução dos impactos ambientais são atrativos também sob o ponto de vista dos investidores. Considerando-se os métodos baseados no fluxo de caixa descontado, o valor presente líquido é o melhor indicador para tal avaliação, pois permite decidir qual é o melhor entre dois projetos excludentes, além de apresentar uma rotina de cálculo simples e de fácil entendimento pelos usuários. Este trabalho teve como objetivo propor uma ferramenta para a análise da qualidade dos investimentos em um sistema de aproveitamento de água pluvial, baseada na otimização do valor presente líquido, por meio da técnica de Particles Swarm Optimization. Para demonstrar a utilização da ferramenta proposta, desenvolveu-se um estudo de caso para uma edificação pública existente. Foram considerados três cenários para a tarifa água: sem reajuste e com valores limite e máximo do reajuste histórico das tarifas da concessionária local: 5,69 e 19,63% ao ano. Em todos os cenários foram encontradas duas alternativas: existência de cobrança da tarifa de esgoto correspondente ao volume de água pluvial utilizado e inexistência dela. Os resultados obtidos com o uso da ferramenta proposta podem auxiliar na tomada de decisão para uso dos sistemas de aproveitamento da água pluvial.

Analysis of the quality of investments should be part of decision-making for implementing rainwater-harvesting systems in order to evaluate whether investments in environmental impacts mitigation are also attractive from the point of view of investors. Considering discounted cash flow methods, net present value is the best indicator for this analysis, because it allows deciding which is the best between two mutually exclusive projects, and it also presents a simple calculation routine and is easily understood by users. This work aimed at presenting a decision-making analysis tool for rainwater-harvesting systems, which is based on the maximization of net present value, using the Particles Swarm Optimization technique. The decision tool was used to evaluate the quality of the investments for implementing a rainwater-harvesting system, considering a building of the public tax category. Three scenarios of the water bill were considered: current rate structure and increases of 100%, 150% and 200%. All scenarios contemplate two alternatives: with sewage rate corresponding to the rainwater use and no fee. Results illustrate opportunities for investments in rainwater-harvesting systems.

Toxicological study of nitrate/nitrite concentration in harvested rainwater from Kannur District of Kerala.

Rainwater harvesting is a technology used for collecting and storing rainwater from rooftops. The techniques usually followed in Asia and Africa arise from practices employed by ancient civilizations in these regions, and still serve as a major source of drinking water supply in rural areas. Of late, in Kerala (India), scientific methods are being increasingly employed for rainwater harvesting. But in some areas, for instance in Kannur district, where this study was conducted, the recommended scientific method is not followed properly, and high levels of nitrates (or nitrites) are said to be present, which can cause nitrate toxicity. This study mainly concentrates on the water quality analysis of rainwater harvesting area in Kannur district of Kerala. The following quality parameters were analyzed: pH, electrical conductivity, alkalinity, chloride, total dissolved solids (TDS), hardness, iron, ammonia, nitrate, nitrite, sulphate, and absorbed oxygen. It was found that most of these were within the prescribed international standards, but some parameters such as total dissolved solids (TDS), nitrate, nitrite and absorbed oxygen were quite high as compared to ground water. When the water was passed through commercially available filters, sand and gravel, or charcoal, the concentration of nitrate, nitrite, total dissolved solids and absorbed oxygen came down to acceptable levels, and the water satisfied all the drinking water quality standards, equivalent to the highest quality mineral water.