Rainwater Harvesting Potential Research Articles

Feasibility of roof top rainwater harvesting potential - A case study of South Indian University

Shortage of water source has been a major problem for rapidly growing cities in country like India due to increase in consumption of water. Besides this the coastal cities like Mangaluru are currently challenged by temporary floods due to increased precipitation. Hence it demands a flawless planning for managing the water resource. Rooftop Rainwater Harvesting (RTRWH) has proven to be the most economical and environmental friendly method. The principal objective of this study is to design the RWH system for a South Indian University (SIU), to transform the present campus with green initiative by effective utilization of water resource. An integrated study on rooftop storm water runoff for quantitative and qualitative analysis was conducted. The SIU can resolve the water scarcity issue by accumulating about 1,13,678.9 m 3 of stormwater from rooftop in a year, and use it during the non-monsoon season. These findings can significantly influence the similar RTRWH initiatives in various government and private establishments for sustainable water management. • The study evaluates the potential of Roof-Top Rainwater Harvesting (RTRWH) at a South India University (SIU). • A detailed observation on rainfall statistics and influence toward RTRWH potential is discussed in this article. • In order to reuse the collected storm water a comprehensive quality analysis was performed and results are discussed. • An optimal site location for constructing a storm water storage tank was determined using Remote Sensing and GIS tool. • The study also includes a constructive design of storage tank with economical cost estimation.

Geomatic Assessment Of Rainwater Harvesting Potential System At Cmr College Of Engineering & Technology

CMRCET campus comprises about 10 of acres land, where water is the natural resource which is being always in high demands. If the demand is not met, then it will lead to water scarcity. Therefore, RWHS can be considered as a best solution for fighting against scarcity of water. Our present study deals with the identification of the study area boundary and marking it as a Polygon in GIS, Rooftops of various block entities, paths and pavements were digitized using the Polygon vector in GIS. GIS technique is employed for locating boundaries of the study area and for calculating the areas of various types of rooftops and paths. With the application of GIS, it is possible to assess the total potential of water that can be harvested. Potential of rainwater harvesting refers to the capacity of an individual catchment that harnesses the water falling on the catchment during a particular year considering all rainy days. This present study will enable us to identify the suitable type of water harvesting structure along with the number of structures required. Our aim is to maximize water storage and minimize the runoff through drains without making use of it. Thus, Rainwater Harvesting and Conservation aim at the optimum utilization of the rain water.

Governança de água e planejamento urbano: aproveitamento de água de chuva para construção de cidades mais resilientes

Climate change and the increase in the urban population are strong stressors for water resources, making it necessary to discuss the construction of urban systems that are resilient and sensitive to water. In this way, the use of rainwater presents itself as an important alternative for accessing water and reducing pressure in water sources. This research aimed to identify the potential of rainwater harvesting in thirteen cities in the State of Paraiba by means of computer simulations. Twelve scenarios were adopted for each city and it was found that the capture of rainwater in the study sites is feasible to decrease the demand for drinking water, corroborating for the decentralized water supply and the increase of urban resilience. Finally, it is understood that, when added to urban planning, this technology tends to favor less hydric vulnerable cities.

Watershed modelling development for generating runoff estimation of Sarida Catchment/Central West Bank.

Watershed modelling was carried out in Sarida Catchment in the West Bank (Palestine) in order to determine the physical characteristics of the watershed. Generated storm water and runoff were estimated for watershed sub-catchments for enhancing the potentiality of rainwater harvesting development. Climatic data across eight years (seven wet seasons) were used for watershed modelling by using the software application systems of Watershed Modelling and Hydrologic Modelling. The Geographical Information System (GIS) and Microsoft Excel were used as well for the estimation of different model parameters and features. The physical and meteorological characteristics for each sub-catchment including land use, topography, soil, rainfall, and other parameters were identified. The model results provided sensitive conceptual principles for understanding the runoff mechanisms in the watershed. The average generated storm water over the seven seasons (2008/09 to 2014/15) is 23.16 and 13.44 Mm3/year for northern and southern sub-catchments in Sarida watershed, respectively. The generated runoff of the sub-catchments over this period ranged between 2.13 and 23.18 million cubic meters per year. The results suggest a high potential for rainwater harvesting to promote agricultural development and the need to establish a climatic monitoring network in Sarida watershed, as well as in other catchments in the West Bank, for better informing watershed management practices and policies.

Assessing rainwater harvesting potential in a humid and semi-humid region based on a hydrological model

Study regionThe upper regions of the Yangtze River in China. Study focusEvaluating the rainwater harvesting potential (RWHP) is essential for alleviating regional drought and water shortage and solving water shortage and water crisis globally. However, previous studies have mainly focused on arid and semi-arid zones, whereas the assessment of RWHP in humid and sub-humid zones during the dry season is lacking. To fill this gap, a soil and water assessment tool based on meteorology, digital elevation model data, soil, land use, and observed streamflow, was constructed for a selected site. Additionally, a method of assessing RWHP in humid and semi-humid zones was proposed. New hydrological insights for the regionThe results indicate that the average annual RWHP throughout the dry season (March-August) in the upper regions of the Yangtze River is 5657.02 × 105 m3, and that for spring and summer are 1766.21 × 105 and 3890.95 × 105 m3, respectively. Regarding the RWHP structure, it was observed that surface runoff (42.59 %) > groundwater recharge (29.53 %) > base-flow (19.43 %) > soil water content (7.16 %) > lateral flow (1.29). The analysis indicated that the spatial distribution of RWHP is consistent with that of drought, and can alleviate agricultural drought. The inter-annual variation of RWHP was relatively stable, exhibiting a weak increasing trend at the seasonal (dry, spring, and summer) and monthly (March–August) scales during 1999–2018. RWHP trends are primarily regulated by rainfall with the trend for a small part of the region being influenced by evapotranspiration. Our study provides a reference for the evaluation of RWHP in dry seasons in humid and semi-humid zones.

Assessment of roof water harvesting potential of Navsari city of Gujarat State, India by Remote sensing and Geographic information system (GIS)

Due to the water scarcity scenario in many parts of the Navsari city, Gujarat State in India, it is imperative to adopt cost-effective technologies that could harvest rainwater for satisfying drinking water requirements. The study was conducted with the aim of assessing the rainwater harvesting potential of Navsari city using remote sensing and Geographic Information System (GIS). The built-up areas of Navsari that could harness rainwater were identified by remote sensing and GIS. The effective built-up area contributing to rainwater harvesting was found to be 3.37 km2. The classification was carried out using “Remap” to assess the extent of the built-up area. The city was divided into equal grids and classification of each grid was implemented. The ground truth data was used for the evaluation of the built-up area. The roof water harvesting potential was estimated considering the average annual rainfall of 1621 mm and adopting suitable runoff coefficients. The rainwater harvesting potential of roofs for rainfall of different probabilities was estimated. For return periods of 10 years, 25 years, 50 years and 100 years, the roof water harvesting potentials were estimated to be 0.226, 0.261, 0.287 and 0.312 Million Cubic Metres (MCM), respectively. The estimated average roof water harvesting potential of Navsari city was 164 million litres per year, capable of satisfying the drinking water demand of approximately 1.12 lakh people annually. The rainwater harnessed from the rooftop could augment the current water supply and immensely help in fulfilling the drinking water demand of Navsari.

Socioeconomic potential for rainwater harvesting systems in southern Brazilian municipalities

Abstract The implementation of rainwater harvesting (RWH) systems depends on technical and socioeconomic assessments. However, most studies do not consider socioeconomic aspects, which could lead to different degrees of RWH implementation and technology selection due to economic constraints and local regulations. We evaluated the socioeconomic potential for RWH as an alternative for the water supply of 24 southern Brazilian municipalities with less than 50,000 inhabitants. A total of 10,080 RWH configurations were assessed and a reliability analysis was carried out to define the RWH system configurations potentially implementable (RWH+) in each municipality. RWH economic benefits were estimated from a social point of view, based on the reduction of the monthly water payment. Overall, RWH+ supplying higher demands with higher economics savings were feasible, as expected. However, several municipalities that showed RWH+ supplying 100% of the domestic water demands obtained lower economic savings, due to low water tariff and water consumption. Still, a set of municipalities presented RWH+ for rainwater demand replacing 50% to 60% of the residential demand, for which the high water tariffs were reflected in higher economic savings. The advantages of using the RWH systems stand out even more when the investments at Federal and Local levels are considered.

Application of HEC-HMS Model for Evaluation of Rainwater Harvesting Potential in a Semi-arid City

Application of HEC-HMS Model for Evaluation of Rainwater Harvesting Potential in a Semi-arid City

Assessment of adoption potential of rooftop rainwater harvesting to combat water scarcity: a case study of North 24 Parganas district of West Bengal, India

Assessment of adoption potential of rooftop rainwater harvesting to combat water scarcity: a case study of North 24 Parganas district of West Bengal, India

Rainwater harvesting potential in water abundant and scarce regions in northeast Brazil using remote sensing

Rainwater harvesting potential in water abundant and scarce regions in northeast Brazil using remote sensing

Appraisal of Rainwater Harvesting in ASCOT Engineering Zabali Campus Baler Aurora

One of the problems encountered by the engineering students and faculty and staff members of Aurora State College of Technology (ASCOT) is the water supply for toilet and urinal flushing. This problem is attributed to the location of the area which is 50m above sea level. The main water source of the campus is the water coming from water falls which requires pipelines that are vulnerable from heavy damage during natural disasters and illegal intrusion. To address the scarcity, rainwater harvesting is considered by the researchers and in this research, the researchers assessed the potential of rainwater harvesting using the roof of an existing building in the area. The result shows that harvesting water from rainfall can become a solution in the scarcity of water in the area. Based on 10-year rainfall data from PAGASA Baler Station Complex which is Located approximately 4.3 km from the location of the study that on average, during December, November and October the amount of rainfall can fulfill the demand of water for toilet and urinal flushing up to 102.54 %, 76.98% and 75.40% respectively. The total area of rainwater collector in this study is about 186.87 square meter. Data also shows that on average, the month of August has the minimum potential of fulfilling the demand water for the area but by increasing the area of collector by 68%, 100% of the demand for this specific purpose maybe met during the driest month of the year

Assessing the potential for rooftop rainwater harvesting and its physio and socioeconomic impacts, Rawal watershed, Islamabad, Pakistan

The purpose of the current study is to investigate the potential of rooftop rainwater harvesting (R-RWH) and its physio- and socioeconomic effects on the peoples in two catchments (Salghara and Malach) of the Rawal watershed, Pakistan. A questionnaire-based analysis was used not only to gather the required design parameters (roof area, household size, water usage) but also to investigate the physio- and socioeconomic effects. Results revealed that the highest rainfall change is found from January to March and June to September but the lowest was observed in November–December near the Salghara region. In the Malach region, the positive rainfall is measured in February and June but the negative is found in May, July, and August. The survey analysis showed that 77 m3 minimum roof area is required and suitable material to implement the R-RWH for a 6-family size. 121 m3 and 76 m3 annual average water yield is recorded for Salghara and Malach catchments, respectively. A storage tank capacity of 13 m3 and 32.5 m3 is observed for Salghara and Malach, respectively. This difference in capacity is found due to the length of the dry periods. The low-cost rainwater harvesting system is proposed between 600 and 400 USD per household. Furthermore, it was noticed that people do believe rooftop RWH can positively impact both their economic and health conditions, particularly for women as they spend most of their time struggling to fetch water. It is concluded that rooftop RWH has great potential as an alternative household water source in the Rawal watershed catchment regions.

Potential of rainwater harvesting in Cimahi, West Java, Indonesia

Drinking water services in Cimahi City are only 18.6% of the population, lower than the average of West Java Province and the National figure of 80.82%. Population density 15,281 population/km2 on the other hand the problem of lack of raw water sources, heavily polluted rivers, 47% of well water is not feasible as a source of drinking water causing a lack of drinking water services for its residents. This problem needs to get a solution, can efforts to use rainwater in Cimahi City be carried out? This study aims to identify water supply systems, the potential, and problems of drinking water supply through rainwater harvesting. The method used is descriptive through analysis of drinking water supply systems through rainwater harvesting including analysis of average drinking water demand, analysis of the potential and problems of drinking water supply, and identification of technical aspects of directives through rainwater harvesting in Cimahi City. The results obtained in this study are that the City of Cimahi has the potential to use a water harvesting system as an alternative for community drinking water supplies. From a technical point of view, Cimahi City can use a combination of individual and communal systems.

Estimation of rainwater harvesting potential for emergency water demand in the era of COVID-19. The case of Dilla town, Southern, Ethiopia

Safe and adequate quantity of water is crucial for the implementation of infection prevention and control measures during the prevention of COVID-19. Rainwater harvesting could be an optional water source to fulfill or support the emergency water demand in areas where there is abundant rainfall. The study aimed to assess the rainwater harvesting potential and storage requirements for households and selected institutions and to determine its adequacy to satisfy the emergency water demand for the prevention of COVID-19 in Dilla town, Southern Ethiopia. Rainwater harvesting potential for households and selected institutions were quantified using 17 years’ worth of rainfall data from the Ethiopian Meteorology Agency. To address the rainfall variability, we computed the confidence limits of monthly harvest-able rainwater potential using confidence intervals about the mean as well as confidence intervals using Coefficient of Variation (COV) of monthly rainfall. The storage requirements were also estimated by considering the driest and west seasons and months. The average annual rainfall in Dilla town was 1464 mm. Households with a roof area of 40 and 100 m2 have the potential to harvest 7.2–39.66 m3 and 19.11–105.35 m3 of rainwater respectively. Similarly, the rainwater harvesting potential for the selected institutions was in the range of 34524.5–190374.5, 4070.8–14964.8 , 1140.4–6288.6, 4561.7–25154.3, 5605.8–14152.8 , and 402.4–2219.1 m3 of rainwater for colleges, vocational schools, secondary schools, primary schools, Dilla University Referral Hospital and health centers respectively. These institutional rainwater harvesting potentials can address, 24–132.2, 222.4 –817.8, 59.4–327.3, 34.6–190.9, 94.5–238.5, and 28.2–155.7 % of the colleges, vocational schools, secondary schools, primary schools, Dilla University referral hospital, and, health centers emergency water demand respectively. Rainwater can be an alternative water source for the town in the prevention and control of COVID-19. Further applied researches must be conducted that can address the rainwater quality and treatment for ease of use.

Integrating GIS-Based MCDA Techniques and the SCS-CN Method for Identifying Potential Zones for Rainwater Harvesting in a Semi-Arid Area

An increasing scarcity of water, as well as rapid global climate change, requires more effective water conservation alternatives. One promising alternative is rainwater harvesting (RWH). Nevertheless, the evaluation of RWH potential together with the selection of appropriate sites for RWH structures is significantly difficult for the water managers. This study deals with this difficulty by identifying RWH potential areas and sites for RWH structures utilizing geospatial and multi-criteria decision analysis (MCDA) techniques. The conventional data and remote sensing data were employed to set up needed thematic layers using ArcGIS software. The soil conservation service curve number (SCS-CN) method was used to determine surface runoff, centered on which yearly runoff potential map was produced in the ArcGIS environment. Thematic layers such as drainage density, slope, land use/cover, and runoff were allotted appropriate weights to produced RWH potential areas and zones appropriate for RWH structures maps of the study location. Results analysis revealed that the outcomes of the spatial allocation of yearly surface runoff depth ranging from 83 to 295 mm. Moreover, RWH potential areas results showed that the study areas can be categorized into three RWH potential areas: (a) low suitability, (b) medium suitability, and (c) high suitability. Nearly 40% of the watershed zone falls within medium and high suitability RWH potential areas. It is deduced that the integrated MCDA and geospatial techniques provide a valuable and formidable resource for the strategizing of RWH within the study zones.

Potential Water Balance using Rainwater: An Analysis of Delhi, Megacity in India

Delhi is one of the most water stressed cities in the world. This study aimed to explore the potential of Rainwater Harvesting (RWH) as an alternative source of the water supply for Delhi. Mass curve method has been used to understand the feasibility of RWH, indicating that an average roof of 60 m2 in Delhi will collect 3,64,800 L of water in a year for an average family size of five people. The present study assumed that financial constraints, erratic rainfall, unclear legal guidelines, poor public perception, and a lack of commitment from the politicians are possible challenges.

Feasibility of rainwater harvesting from residential rooftops in Jordan

Rainwater harvesting is adopted to face water scarcity in arid regions. Many studies were developed in Jordan to estimate the potential of water harvesting for several uses. However, the precise estimation of water saving and cost benefits for the potential of rainwater harvesting from the roofs of residential urban areas is insufficient. Therefore, the objective of this study was to investigate the feasibility of rainwater harvesting from residential rooftops in all the eighty-nine Jordanian districts. The forecast number of buildings was calculated from 2016 to 2025 using building growth rate, where the number of houses and villas was adopted only. The long-term rainfall average from 1937 to 2017 was used. Two scenarios were used to assess the potential of rainwater harvesting; numerical (as scenario 1) and tabulated by plumbing code (as scenario 2) for the years from 2019 to 2025. Also, the growth rate of one cubic meter of water cost was calculated to find the money saving potential for the water companies in Jordan. The results indicated that the water harvesting potential was different between two scenarios in the districts which have annual rainfall more than 100 mm was efficient in scenario 1 compared to scenario 2 with the projected financial return which was increased from $5.4 million at 2019 to reach $33.4 million at 2025, while in the districts which have annual rainfall less than 100 mm was more efficient in scenario 2 compared to scenario 1 with the projected financial return which was increased from $2.4 million at 2019 to reach $14.6 million at 2025.

Rainwater Harvesting Potentials in Commercial Buildings in Dhaka: Reliability and Economic Analysis

Despite numerous studies on residential rainwater tank, studies on commercial rainwater tank are scarce. Corporate authorities pay little heed on this sustainable feature. With the aim of encouraging corporate authorities, this study presents the feasibility and economic benefits of rainwater harvesting (RWH) in commercial buildings in the capital city of Bangladesh, where water authority struggles to maintain town water supply. The analysis was conducted using a daily water balance model under three climate scenarios (wet, dry and normal year) for five commercial buildings having catchment areas varying from 315 to 776 m2 and the storage tank capacity varying from 100 to 600 m3. It was found that for a water demand of 30 L per capita per day (lpcd), about 11% to 19% and 16% to 26.80% of the annual water demand can be supplemented by rainwater harvesting under the normal year and wet year climate conditions, respectively. The payback periods are found to be very short, only 2.25 to 3.75 years and benefit–cost (B/C) ratios are more than 1.0, even for building having the smallest catchment area (i.e., 315 m2) and no significant overflow would occur during monsoon, which leads to both economic and environmental benefits. Though the findings cannot be translated to other cities as those are dependent on factors like water price, interest rate, rainfall amount and pattern, however other cities having significant rainfall amounts should conduct similar studies to expedite implementations of widescale rainwater harvesting.

Rainwater harvesting potentials for drought mitigation in Tunisia: Water quality monitoring

Rainwater is extremely important for the arid regions of Tunisia for a better valorization of this water, the indigenous of these regions decided to build earthen cisterns (Majel and Fesquia) to collect rain water, to satisfy their needs and to have sufficient long-term water reserve in case of prolonged drought. Despite the difficulties faced to access the mountainous regions, a survey was conducted concerning all characteristics of earthen cisterns and their uses. 120 samples of water have been analyzed in the laboratory for their physicochemical parameters such as pH, EC, sodium, chloride, bicarbonate and microbiological quality parameters such as total coliforms, and Escherichia coli. It has been noted that the majority of people (62%) used rainwater as drinking water, for animal watering and as supplementary irrigation. In fact, physic-and chemical properties of, the rainwater samples collected are suitable for consumption according to WHO 2017 standards. However, the results of our microbiological indicator analyses suggested that rainwater stored in Majel and Fesquia are not suitable for human consumption without any treatment. Rainwater can be considered as potential source for non-potable uses, such as irrigation. The samples collected were categorized as suitable with regard of SAR belonged to the excellent to good class.

Rainwater harvesting potential in Cox's Bazar to reduce groundwater usage

Rainwater harvesting potential in Cox's Bazar to reduce groundwater usage