Rainwater Harvesting Systems Research Articles

PENGGUNAAN ALAT BANTU MENGAJAR (ABM) BAGI KURSUS DUG30023 GREEN TECHNOLOGY COMPLIANCE: KAJIAN DILAKUKAN DI POLITEKNIK KUCHING SARAWAK

The use of a green technology replica model as a teaching aid to help students understand the types of green technology based on renewable resources in the DUG30023 Green Technology Compliance course. The course DUG30023 Green Technology Compliance is a course offered by the Polytechnic. At Polytechnic Kuching Sarawak, this course is taken by Business Management Diploma students and Geomatics Diploma students. Through this course, students are exposed to green practices and the effects that have and will occur in relation to the environment. This green technology replica model is produced using used materials such as boxes, plastic bottles and polystyrene. This mini replica model provides various types of green technology such as Rainwater Harvesting System (SPAH), windmills and photovoltaic systems. In addition, it also provides a QR code that connects to a video about the green technology. This video was produced using PowToon to attract the attention of students to watch it. In addition, there is also a QR code that connects to the questionnaire to study the effectiveness of the mini replica model in teaching and learning.

Rainwater harvest, an alternative for water supply for human consumption

One of the millennium development goals is to have the world population without sustainable access to safe drinking water and basic sanitation. Another challenge of the millennium also states that every human being has the right to clean water, which implies access to minimum quantity and quality values to meet their basic needs; however, rapid urbanization, industrialization and population growth, have reduced the availability of drinking water. In this sense, several alternatives have been practiced in order to solve this problem. Recent studies have demonstrated the economic, social and environmental benefits of harvesting rainwater in different regions, water harvesting systems provide flexible solutions that can properly meet the needs of existing and future demands. The overall objective of this research was to monitor the quality of water stored in rainwater harvesting systems installed in the state of Zacatecas, Mexico this technology was developed by a group of researchers CA-177 of the Autonomous University of Zacatecas. The determination of cations Na +, K +, Mg2 +, Ca2 + and trace elements was performed by atomic absorption (AA Team ThermoScientific ICE 3300) under the NMX-AA-012- 200-SCFI APHA standard. Results indicate that quality of water stored in tanks receiving rainwater meets the Mexican Standard NOM-127-SSA1-1994 and WHO for human consumption. It is concluded that physico-chemical and biological characteristics of harvested water is suitable for all purpose, demonstrating that this technology is inexpensive and represents a sustainable alternative to supply water in marginal areas of Zacatecas and Mexico.

Multi-Objective Performance of Detention Basins and Rainwater Harvesting Systems Using Real-Time Controls with Rainfall Forecasts

Climate change and an increase in urbanization are severely testing urban drainage systems; at the same time, population growth is leading to an increase in demand for water resources, while climate change is more likely to reduce the amount of water that is available to meet this demand. The present study finds a solution to both problems by assuming a hybrid use of detention basins, i.e., providing a real-time control system (RTC) for the outfall discharge managed according to the rainfall forecast and the water level in the tank, to reuse rainwater for non-potable use and, at the same time, to guarantee the hydraulic protection of the downstream system. Twenty-seven scenarios were simulated using the numerical model SWMM 5.1, assuming different types of controls on the discharge. The simulations show a non-potable water-saving efficiency from a minimum of 32% to a maximum of 90%, and the reduction in volume discharged is between 11% and 31%, while the peak flow rate varies more significantly depending on the type of control used. These results highlight the detention basins’ potential deriving from the hybrid use of this system with rainwater harvesting systems.

Stunting Allevation in Kalibaru Subdistrict, North Jakarta trough the Implementation of Integrated Urban Farming and Rainwater Harvesting System

Stunting remains a serious public health problem in urban areas. A contributing factor to the high prevalence of stunting in the region is the limited availability of clean water and nutrient-rich foods. In addition, this sub-district is at risk of experiencing a clean water crisis in the future. This study aims to analyze the effectiveness of the integration of rainwater harvesting (RWH) and urban farming to overcome stunting, access to clean water, and food supply in Kalibaru District, North Jakarta. The method used is a social experiment through three processes: community education, RWH installation, and urban agricultural system development. For each process, data collection was carried out through field observations and surveys of 39 respondents. Community knowledge was measured before and after the process through questionnaires, and the results of the integration of RWH and urban farming systems were described. The results showed an increase in public knowledge about the benefits of RWH integration and urban farming. RWH has helped alleviate the problem of clean water availability effectively and economically. Meanwhile, urban agriculture has given communities better access to nutrient-rich foods, which in turn can help reduce the problem of stunting.

Rainwater: Harvesting and Storage through a Flexible Storage System to Enhance Agricultural Resilience

Many climatic variables are projected to occur with more intense and frequent extreme events, possibly unpredictable patterns and negative feedback loops with other environmental processes. Agriculture has faced uncertainty regarding ground temperature and rainfall distribution during the last few years, making water availability one of the major concerns for farm management. In this scenario, rainwater harvesting could represent a powerful tool to mitigate this problem, and consequently, the research community has been fostering new technical solutions. On the other hand, a few studies on agronomic assessment of rainwater harvesting systems are present in scientific literature. The present study reports preliminary data of a long-term study on a Flexible Water Storage System (FWSS) evaluating the possibility of enhancing agriculture systems resilience, shifting from rainfed production to irrigated agriculture relying on excessive rainfall, collectible from extreme events. The idea of intercepting excess rainfall, which is generally lost, thanks to an innovative water harvesting system, and using it to mitigate drought stress for crops is in line with sustainable approaches aiming to improve the resilience of agricultural systems. The results highlighted that the system studied could potentially collect an annual average of 831.7 m3 of water, mitigating the excess of water in the ditch that can potentially cause flooding and storing fresh water to provide irrigation during dry periods.

The Feasibility of Rainwater Harvesting Systems in Buildings with Green Roofs: A Case Study Based on the Köppen Climate Classification

The construction of green roofs (GR) combined with rainwater harvesting systems (RWHSs) in buildings can increase the advantages of each of these technologies, being a very promising solution to combat climate change and increase the sustainability of cities. However, the viability of this joint solution significantly depends on local climatic conditions. The planet’s climate classification, known as the Köppen climate classification, is one of the most widely used climate classification systems. The Köppen climate classification divides climates into five main climate groups, with each group being referenced based on seasonal precipitation and temperature patterns. In the specific case of mainland Portugal, according to the Köppen classification, the climate is divided into two regions. In this article, case studies are developed for two Portuguese climatic regions, seeking to demonstrate the possibility of using the Köppen classification as a decision criterion for the eventual inclusion of rainwater harvesting systems in buildings with green roofs. For this study, the results of a previous study were applied, through which we obtained an expression to determine the runoff coefficients of green roofs common in Portugal, concluding that the Köppen climate classification can be used as a prior decision criterion regarding its incorporation or exclusion in rainwater harvesting system buildings combined with green roofs, depending on the location.

Public perceptions of rainwater harvesting (RWH): comparing users and non-users of RWH systems

ABSTRACT The UK’s abundant municipal water supply has resulted in slow progress with the uptake of rainwater harvesting (RWH) systems within the home. Research has indicated that exploring public preferences for domestic RWH are necessary for increasing demand. Here, we use explicit and implicit tests to investigate public perceptions of RWH for non-potable uses, and compare perceptions of respondents with and without domestic RWH systems. RWH is perceived positively by most respondents indicating an openness and acceptance of this technology (and/or lack of strong negative attitudes). Implicit attitudes are generally more positive than explicit, especially in respondents with RWH systems, implying that the positivity is deep-seated in their subconsciousness. We also reveal differences between subconscious (implicit) beliefs and practical difficulties (explicit opinions). Outdoor uses of rainwater are preferred, hence, more work in promoting indoor uses is needed to maximise the resource potential of UK rainfall and uptake of RWH systems.

The role of citizen participation in advancing sustainable water solutions: The Mexico City case study

Providing water equally and sustainably in megacities is a challenge that requires integrating people's needs and concerns. This defy is assessed from Mexico City, from which a series of observations and a methodology analyze and compare scenarios of water conditions in the 16 municipalities, integrating citizen participation to implement sustainable actions that improve water supply. Citizens' reports from 2002 to 2022 in a free digital platform were used to correlate the variables of leaks and water shortages. This was complemented with information from water endowment (Liters/day/inhabitant) from groundwater sources that supply the city. For the latter, projections (with the additive model) to 2022 were generated since records were available up to 2018. To identify priority areas to invest in measures that favor water supply in the municipalities, we further considered the adaptation measures applied by the city government, e.g., the purchase of portable water tanks and Rainwater Harvesting Systems (RWHS). Both measurements proved essential but need to be of more extensive application. Government and society must improve their use by promoting conscious consumption of water, impulse repairing leaks, further implementing Rainwater Harvesting Systems (RWHS), and integrating the resources (inputs/outputs) in a water circularity model, maximizing their utility and recirculation.

Preliminary theoretical design of crossflow water turbine for rainwater rooftop harvesting system

Harvesting energy is essential especially now that the demand of energy is high but the fuel supply is limited. This study theoretically designs the 5 m low head crossflow turbine in rainwater harvesting system. The characteristics of the site condition, the runner geometry, the blade geometry, and the turbine specification had been identified and the geometrical model of the design is shown. This paper reported the collection of theoretical formula for the design of low head crossflow turbine that can be used for rainwater harvesting system. The dimensional form of equations, as presented in Section 2, resulted to the two, four, and two parameters that represent the dimensions of the turbine, runner and the blade, respectively. As a conclusion, the designed turbine can be used for rainwater harvesting system with an efficiency that was calculated to be 88% with 22 kW expected power generated for 5 m head.

Performance of a Rainwater Harvesting Tank Under Under Varying Non-Potable Demand: Case Study in Kubang Semang, Penang

Rapid development and climate change has endangered the availability of water resources worldwide. This study look into the potential of the applying a rainwater harvesting system (RWHS) for non- potable water usage in a doublestorey residential terrace house using Tangki NAHRIM 2.0 (TN2.0). TN2.0 is a web application that adopt the yield-after-spillage (YAS) convention to identify the optimum rainwater tank size. It is found that for a house of size 86.86 m<sup>2</sup>, the optimum tank size is 2 m<sup>3</sup> with water-saving and storage efficiency values of 51% and 63.2% respectively. Additionally, the performance of the optimum tank size of 2 m<sup>3</sup> was further examined under different water demand. It was found that a 2 m<sup>3</sup> tank was still able to save water up to 42.1% for a family of 10 persons. Meanwhile, the storage efficiency shows a little increment from 63.2% to 67.8%.

Method of Calculation the Efficiency and Economic Viability of Rainwater Harvesting Systems

Purpose: study the methodology for designing a rainwater harvesting system and evaluate its technical and economic viability for supplying water for washing vehicles in the garage of the State University of Rio de Janeiro (UERJ), Maracanã campus. Theoretical framework: water supply in urban areas faces complex challenges, due to changes in minimum flows, pollution of water sources, demand growth, variability and uncertainties in the rainfall regime. Rainwater harvesting systems have become an alternative to supply non-potable demand, reducing the need for consumption by the public supply system. Method: evaluation of rainfall in the region of Tijuca, Rio de Janeiro, to meet the demand for water for washing vehicles through a rainwater harvesting system. The calculations of the catchment area and volume of the reservoirs used data, with a historical series between 2009 and 2018, statistical adjustment of the Gumbel frequency distribution and a ten-year recurrence period. Results and conclusion: An average percentage of 61 to 75% of demand was met, depending on rainfall variations and the capacity of the reservoir adopted. Average monthly savings of between US$ 200 and US$ 300 were found, corresponding to a period of 4 to 24 months for cushioning investments in the implementation of the system. Research implications: The research contributes with data that reinforce the importance and efficiency of correctly sized systems, as an alternative source to meet non-potable demands. Originality/value: the article presents a specific methodology for sizing the main elements in a system (catchment area and reservoir volume) and configures excellent technical and economic viability in the proposed use.

Evolution of water quality in rainwater harvesting systems during long-term storage in non-rainy seasons

The development of rainwater utilization strategies has relied on rainwater harvesting (RWH) systems for centuries to alleviate the pressure on water resources. However, there are still significant knowledge gaps regarding the changes in water quality in RWH systems during long-term storage in non-rainy seasons. This study evaluated the water quality processes in RWH systems through static rainwater storage experiments for approximately 60 days. The results revealed that nutrients in rainwater accumulated in sediment during storage. Disturbance and redox conditions at the rainwater-sediment interface contribute to the release of sedimentary facies materials. The rainwater showed distinct DO stratification, with the biochemical reactions of sedimentary facies being the primary factor driving oxygen consumption. ORP and turbidity showed positive correlations with COD (r = 0.582; 0.572), TOC (r = 0.678; 0.681), TN (r = 0.452; 0.439), and NH4+-N (r = 0.502; 0.553) (P < 0.05). The regulation of water quality and extension of the usage cycle were identified as critical factors influenced by DO. In addition, bacteria share similar ecological niche preferences. These findings provide scientific evidence for the high-quality reuse of rainwater in decentralized RWH systems during long-term storage in non-rainy seasons.

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

Product Design and Biomimetics

Building professionals face urgent and complex challenges related to climate change adaptation and biodiversity loss. It is essential to restructure and upgrade cities to promote ecological and social health rather than damage it. The application of biomimetics emerges as a solution where whole ecosystems and their functions are mimicked to significantly improve the ecological performance of buildings and urban environments. It contributes to some of the United Nations global Sustainable Development Goals such as “Goal 6: Ensure availability and sustainable management of water and sanitation for all”; “Goal 11: Make cities inclusive, safe, resilient and sustainable”; “Goal 12: Ensure sustainable consumption and production patterns”; “Goal 13: Take urgent action to combat climate change and its impacts”; and “Goal 15: Sustainably manage forests, combat desertification, halt and reverse land degradation, halt biodiversity loss”. The aim is to link research with practical development, sharing the hypothesis that in the future buildings and cities can be active contributors in socio-ecological systems, through strategic and technological approaches. A building has been designed in Granada that integrates with ecosystem services to address water stress and apply regenerative design principles. Extensive research covers the topics mentioned above, as well as important elements for future practical applications. The result is a building with a cyclic rainwater harvesting, purification and reuse system that meets the established objectives. Rainwater and humidity collecting blades are used, taking advantage of the non-potable resource obtained.

Water Management Program in Telkom University: Planning and Best Practice

This paper discusses the water management conducted by Telkom University, including the fundamental considerations to be taken into account, the implementing organization, the design methods for rainwater systems, and practical experiences in constructing Rainwater Harvesting systems. The management is aware of the conditions and situations related to clean water users, estimates of clean water requirements, potential water sources, and the campus environmental situation. Based on various studies and supported by rainfall data from the Meteorology, Climatology, and Geophysics Agency, a simple calculation was used to derive the design of the Rainwater Harvesting system, which was subsequently implemented. There are several lessons learned from this implementation, including the need for improvements in the foundation structure of soak pits, recommending the construction of ground tanks during the dry season, and the flexibility of ground tank size depending on the availability of funds The abstract should state briefly the purpose of the research, the principal results and major conclusions.

Modular life cycle assessment approach: Environmental impact of rainwater harvesting systems in urban water systems

The environmental assessment of urban water systems through life cycle analysis can be facilitated by using a modular approach. This study aimed to use such an approach to assess the impact of implementing rainwater harvesting systems in buildings in the urban environment during their lifespan, from manufacture to disposal. For this purpose, urban systems were divided into components (water treatment plant, potable water distribution, consumer water use, wastewater collection and wastewater treatment plant). The impacts were quantified using the ReCiPe 2016 H impact assessment method, which considers eighteen impact categories. A case study was carried out in the Belém river basin in central Curitiba, southern Brazil, to validate the method. The results showed a reduction of environmental impacts of up to 23.0 % on water treatment plants, up to 19.0 % on potable water distribution and up to 11.3 % on wastewater treatment plants with the implementation of rainwater harvesting systems. The consumer component was the most significant contributor in eight and seven impact categories in the scenarios with and without rainwater harvesting, respectively. Despite the increased infrastructure materials, the results showed potential for environmental impact reduction with rainwater harvesting, mainly in urban water systems' operation process (energy and chemicals consumption). By analysing the total impacts, implementing rainwater harvesting reduced the impacts in eleven out of eighteen impact categories analysed (up to 11.0 % reduction). The principal reductions occurred in ozone depletion, ionising radiation and water use. Finally, the modular life cycle assessment approach proved to be a comprehensive analysis, which can aid in the analysis and decision-making for different scenarios.

The Long-Term Performance of a Rainwater Harvesting System Based on a Quasi-Bicentennial Rainfall Time Series

The University of Genova (Italy) maintains a historical meteorological station that has provided daily rainfall measurements over a quasi-bicentennial period since 1833. The daily rainfall series is analyzed here to assess the impact of long-term precipitation trends on the performance of a rainwater harvesting system. The collected rainwater is used for the irrigation of urban green areas. A behavioral model is applied, involving a dedicated procedure to evaluate the actual soil water content available for vegetation and its decay over time. Non-dimensional indicators are obtained to support adaptation strategies and the sustainable design of the required storage tank. Since both irrigation demand and available water storage depend on the amount of rainfall received, fluctuations in daily rainfall and their trend do affect the performance of the system in a non-trivial way. The results demonstrate that the installation of an RWH system for landscape irrigation is a reliable and resilient solution, at least considering the measured rainfall variations of the last 200 years. In the town of Genoa, no specific adaptation seems necessary in terms of the design of the storage tank other than the usual oversizing, typical of engineering design, to account for uncertainties in the hydrological assessment of any RWH system.

Assessment of the Implementation of Sustainable Stormwater Management Practices in Asian Countries

Numerous efforts have been undertaken by Asian countries to mitigate the adverse effects of urbanization on stormwater management. However, traditional stormwater systems have become overwhelmed due to extensive development, resulting in excessive runoff and frequent floods. As a result, it is crucial to urgently adopt sustainable stormwater management practices (SSMPs) to effectively control water quantity and quality. The goal of this study is to assess the viewpoints of stormwater practitioners regarding green roofs, rainwater harvesting systems (RHS), grass swales, rain garden/bioretention systems, and porous pavement using a SWOT analysis. This was accomplished by distributing questionnaires and evaluating previous studies. The survey showed that participants mostly agreed with the strengths, weaknesses, opportunities, and threats factors related to the chosen SSMPs. Overall, the respondents favoured the implementation of green roofs and grass swales. Further assessments were conducted on these practices in other aspects, confirming that green roofs are the most preferable SSMP for implementation in Asian countries.

Estimation of the Optimal Storage Capacity of Rainwater Harvesting System Considering Regional Climate Characteristics

Due to the influence of climate change, the frequency and intensity of droughts in the Korean Peninsula regions are increasing. Moreover, regional rainfall deviations are increasing, increasing the severity of localized droughts. Accordingly, it is necessary to enhance water resource utilization through recycling and establishing a robust safety net for water supply. This necessitates the implementation of rainwater harvesting systems to augment water reuse capabilities. When planning the storage capacity of a rainwater harvesting system, it is important to calculate the appropriate capacity. Therefore, we created an Excel tool for water balance analysis in this study. It incorporates diverse rainwater uses, their respective usage conditions, and daily usage quantities. A water balance analysis was performed, applying the climate characteristics of different regions. A cost-benefit analysis was applied to the economic feasibility analysis, and a B/C regression curve by region and catchment area was derived based on the results of the water balance analysis. The tool is believed to be an effective support measurement to help decision-makers to calculate the appropriate storage capacity of rainwater harvesting systems in the relevant regions.

Modelling the potential of rainwater harvesting to improve the sustainability of landscape and public garden irrigation

Access to water for irrigating amenity landscape and public gardens is under intense pressure due to the rising competition for water between different sectors, exacerbated by increased drought risk and climate change. Rainwater harvesting (RWH) has the potential to reduce the economic impacts of restrictions on irrigation abstraction in dry years and to build resilience to future water shortages. This study investigated the hydrological viability of RWH for the landscape and public garden sector based on an analysis of five Royal Horticultural Society gardens. A RWH model was developed and combined with on-site observations, key informant interviews and GIS analyses, to estimate irrigation demands and the volumes of harvested rainfall for contrasting agroclimatic years. The results showed that gardens located in wetter regions and with low irrigation water demand to harvestable area ratio had a higher RWH potential and could almost exclusively rely on rainwater to meet irrigation demand, even in dry years. RWH potential is more limited for gardens in drier regions where they would require larger areas to harvest rainwater and for storage. Appropriately designed rainwater harvesting systems offer the potential to remove most of the risk of irrigation abstraction restrictions during dry years and associated impacts on amenity planting quality and visitor experience.