scholarly journals Sizing of Domestic Rainwater Harvesting Systems Using Economic Performance Indicators to Support Water Supply Systems

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 783 ◽  
Author(s):  
Umapathi ◽  
Pezzaniti ◽  
Beecham ◽  
Whaley ◽  
Sharma
Keyword(s):  
Economic Performance ◽  
Performance Indicators ◽  
Rainwater Harvesting ◽  
Water Supply Systems ◽  
Recovery Method ◽  
Capital Costs ◽  
Rainwater Tank ◽  
Catchment Areas ◽  
Harvesting Systems ◽  
Roof Area

This paper presents a monitoring-based investigation of rainwater collection systems using economic performance indicators in a group of households with nonconventional end-uses for rainwater that are not traditionally associated with rainwater supply. The monitored data for five household rainwater tank systems were analysed in two stages. For the first stage, the data was empirically analysed to develop a method to predict effective roof catchment areas. For the second stage, the effective roof catchment areas, together with roof area connection percentages, were analysed against different types of water demands in individual households. The individual systems were investigated for yield capacities, costs and water security using a modified Roof Runoff Harvesting Systems average annual yield model based on daily water balance procedures. The Life Cycle Costing analysis of the systems using the model was based on the Capital Recovery Method by taking into consideration the capital costs as well as ongoing costs for maintenance, replacement and operation of the systems. The analysis established the optimal sizing requirements for the studied rainwater tanks and their corresponding roof area connectivity.

scholarly journals Rainwater harvesting systems for a high quality, supplementary water supply in Nepal

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Jane Nichols
Keyword(s):  
Water Supply ◽  
Cultural Context ◽  
Rainwater Harvesting ◽  
Monitoring And Evaluation ◽  
Water Supply Systems ◽  
High Quality ◽  
Quality Of Water ◽  
Catchment Areas ◽  
Harvesting Systems

Although Nepal is rich in water resources, in 2011 it was estimated that water supply coverage across Nepal is only 80.4 % of which only 17.9 % of water supply systems are considered to be functioning well. Nepal Water for Health (NEWAH) is a Nepali non-government organisation that has implemented several rainwater harvesting systems (RWHS) in the rural hilly regions of Nepal. Hydrological modelling and analysis of NEWAH’s RWHS allowed for the development of a strategy to improve the effectiveness of the systems. RWHS will always be limited in Nepal due to monsoonal rainfall patterns however this high quality water supply should be prioritised for cooking and drinking. Increasing catchment areas to at least 30 m² instead of increasing tank volumes can efficiently increase the water supply. A literature review on the quality of harvested rainwater was completed, and recommendations were made for maintaining the high quality of water throughout collection, conveyance, storage and use. Monitoring and evaluation of installed systems is necessary and recommendations need to be further investigated and considered in Nepal where the social and cultural context can be fully understood. Appropriate use of this technology can provide a high quality supplementary water supply that can directly improve the health of consumers and provide those living in the hilly regions of Nepal with the foundations for further development.

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

Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Md. Rezaul Karim ◽  
B. M. Sadman Sakib ◽  
Sk. Sadman Sakib ◽  
Monzur Alam Imteaz
Keyword(s):  
Water Demand ◽  
Rainwater Harvesting ◽  
Economic Benefits ◽  
Commercial Buildings ◽  
Environmental Benefits ◽  
Capital City ◽  
Balance Model ◽  
Climate Conditions ◽  
Rainwater Tank ◽  
Catchment Areas

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.

Effects of rainwater harvesting on centralized urban water supply systems

2010 ◽  
Vol 10 (4) ◽  
pp. 570-576 ◽  
Author(s):  
C. Grandet ◽  
P. J. Binning ◽  
P. S. Mikkelsen ◽  
F. Blanchet
Keyword(s):  
Water Demand ◽  
Distribution System ◽  
Urban Areas ◽  
Rainwater Harvesting ◽  
Water Supply Systems ◽  
Urban Water ◽  
Water Infrastructure ◽  
Water Age ◽  
Roof Area ◽  
Supply Systems

The potential effect of widespread rainwater harvesting practices on mains water demand and quality management are investigated for three different types of urban areas characterized by different roof area to water demand ratios. Two rainfall patterns are considered with similar average annual depths but very different temporal distributions. Supply reliability and the extent of reliance on the public distribution system are identified as suitable performance indicators for mains water infrastructure. A uniform temporal distribution of rainfall in an oceanic climate like that of Dinard, Northern France, yielded supply reliabilities close to 100% for reasonable tank sizes (0.065 m3/m2 of roof area in Dinard compared with 0.262 m3/m2 in Nice with a RWSO of 30% for a detached house). However, the collection and use of rainfall results in a permanent decrease in mains water demand leading to an increase in water age in the distribution network. Investigations carried on a real network showed that water age is greatly affected when rainwater supplies more than 30% of the overall water demand. In urban water utilities planning, rainwater supply systems may however be profitable for the community if they enable the deferment of requirements for new mains water infrastructure.

scholarly journals Assessment of Rainwater Harvesting Systems in Poor Rural Communities: A Case Study from Yatta Area, Palestine

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 585 ◽  
Author(s):  
Nibal Al-Batsh ◽  
Issam Al-Khatib ◽  
Subha Ghannam ◽  
Fathi Anayah ◽  
Shehdeh Jodeh ◽  
...  
Keyword(s):  
Rural Communities ◽  
Local Community ◽  
Rainwater Harvesting ◽  
World Health ◽  
Water Network ◽  
Catchment Areas ◽  
Harvesting Systems ◽  
One Year ◽  
Health Organization ◽  
The Impact

Yatta is a town located nine kilometers south of Hebron city in the West Bank of Palestine. The town houses over 100,000 people of which 49% are females and has a population that doubles every 15 years. Yatta has been connected to a water network since 1974 serving nearly 85% of its households. The water network is old and inadequate to meet the needs of the population. Water supply made available to the area is limited, estimated at 20 L/capita/day. Residents are thus forced to rely on water vendors who supply water that is 400% more expensive with a lower quality compared to municipal water. Therefore, rainwater harvesting is a common practice in the area, with the majority of households owning at least one cistern. Rainwater harvesting is of great socio-economic importance in areas where water sources are scarce and/or polluted. In this research, the quality of harvested rainwater used for drinking and domestic purposes in Yatta was assessed throughout one year. A total of 100 samples were collected from cisterns with an average capacity of 69 m3, which are adjacent to cement-roof catchment areas of 145 m2 average surface area. Samples were analyzed for a number of parameters including temperature, pH, alkalinity, hardness, turbidity, total dissolved solids, NO3, NH4, chloride and salinity. Results showed that most of the rainwater samples were within World Health Organization (WHO) and Environment Protection Agency (EPA) guidelines for chemical parameters. Microbiological contents such as total Coliforms and faecal Coliforms bacteria were tested. The research also addressed the impact of rainwater harvesting systems on different socio-economic attributes of the local community through a questionnaire that had been filled out before any sample was collected.

Rainwater harvesting: model-based design evaluation

2010 ◽  
Vol 61 (1) ◽  
pp. 85-96 ◽  
Author(s):  
S. Ward ◽  
F. A. Memon ◽  
D. Butler
Keyword(s):  
Rainwater Harvesting ◽  
Simulation Models ◽  
Simulation Modelling ◽  
Design Methods ◽  
Continuous Simulation ◽  
Capital Costs ◽  
Harvesting Systems ◽  
Catchment Size ◽  
The Uk ◽  
Near Future

The rate of uptake of rainwater harvesting (RWH) in the UK has been slow to date, but is expected to gain momentum in the near future. The designs of two different new-build rainwater harvesting systems, based on simple methods, are evaluated using three different design methods, including a continuous simulation modelling approach. The RWH systems are shown to fulfill 36% and 46% of WC demand. Financial analyses reveal that RWH systems within large commercial buildings maybe more financially viable than smaller domestic systems. It is identified that design methods based on simple approaches generate tank sizes substantially larger than the continuous simulation. Comparison of the actual tank sizes and those calculated using continuous simulation established that the tanks installed are oversized for their associated demand level and catchment size. Oversizing tanks can lead to excessive system capital costs, which currently hinders the uptake of systems. Furthermore, it is demonstrated that the catchment area size is often overlooked when designing UK-based RWH systems. With respect to these findings, a recommendation for a transition from the use of simple tools to continuous simulation models is made.

Predicting the hydraulic and life-cycle cost performance of rainwater harvesting systems using a computer based modelling tool

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
R.M Roebuck ◽  
R.M. Ashley
Keyword(s):  
Life Cycle Cost ◽  
Rainwater Harvesting ◽  
Cost Savings ◽  
Potential Cost ◽  
Capital Costs ◽  
Harvesting Systems ◽  
Computer Based ◽  
Monetary Savings ◽  
Lifetime Expenditure ◽  
Financial Issues

Rainwater harvesting systems are a recognised technique for reducing reliance on potable mains supply and as a potential way to save money. However, the widespread uptake of these systems has been slow partly due to the level of uncertainty surrounding hydraulic and financial performance. Current methods of assessment tend to be simplistic, using generalised rather than site-specific data. Often little account is taken of financial issues other than capital costs, such as operating/maintenance and decommissioning expenses. To overcome these shortcomings, a computer based modelling tool called RainCycle© was developed that has the capability to perform more detailed analysis than is possible with existing methods. The program includes a detailed hydraulic model of a typical rainwater harvesting system and also has the ability to explicitly account for all major costs associated with these systems. Modelling a number of proposed designs revealed that many of the current methods overestimate the hydraulic efficiency and potential cost savings that are achievable. However, it was found that water and monetary savings are still possible under favourable conditions. Further, it was found that capital, maintenance and required mains top-up water account for the majority of the whole life costs, whilst energy and decommissioning costs represent a small fraction of the required lifetime expenditure.

scholarly journals RELIABILITY ANALYSIS OF URBAN RAINWATER HARVESTING

2016 ◽  
Vol 10 (1) ◽  
pp. 124-134 ◽  
Author(s):  
Dustin Lawrence ◽  
Vicente L. Lopes
Keyword(s):  
Rainwater Harvesting ◽  
Decision Makers ◽  
Period Analysis ◽  
Rainwater Tank ◽  
Property Owners ◽  
Harvesting Systems ◽  
Tank Design ◽  
State And Local ◽  
The Cost ◽  
Multiple Scenarios

The purpose of this study was to inform decision makers at state and local levels, as well as property owners about the amount of water that can be supplied by rainwater harvesting systems in Texas so that it may be included in any future planning. Reliability of a rainwater tank is important because people want to know that a source of water can be depended on. Performance analyses were conducted on rainwater harvesting tanks for three Texas cities under different rainfall conditions and multiple scenarios to demonstrate the importance of optimizing rainwater tank design. Reliability curves were produced and reflect the percentage of days in a year that water can be supplied by a tank. Operational thresholds were reached in all scenarios and mark the point at which reliability increases by only 2% or less with an increase in tank size. A payback period analysis was conducted on tank sizes to estimate the amount of time it would take to recoup the cost of installing a rainwater harvesting system.

Stochastic modelling of the hydraulic performance of an onsite rainwater harvesting system in Mediterranean climate

2016 ◽  
Vol 16 (6) ◽  
pp. 1614-1623 ◽  
Author(s):  
H. Muklada ◽  
Y. Gilboa ◽  
E. Friedler
Keyword(s):  
Performance Indicators ◽  
Mediterranean Climate ◽  
Storage Capacity ◽  
Rainwater Harvesting ◽  
Stochastic Modelling ◽  
Constant Number ◽  
Specific Storage ◽  
Rainfall Frequency ◽  
Roof Area ◽  
Use Efficiency

The performance of onsite rainwater harvesting (RWH) system in Mediterranean climate was assessed. A stochastic model quantifying the necessary storage, as a function of rainfall (frequency, depth), roof area, residents’ number, specific water use (toilet flushing, laundry) and the required efficiency was developed. Two performance indicators were calculated: water saving efficiency (RSE) – proportion of water used supplied by the RWH system; and rainwater use efficiency (RUE) – proportion of rainwater actually used. The maximum storage capacity and WSE decreased with increasing number of residents for a given roof area, and with an increasing roof area for constant number of residents. For variable storage volume, RUE increased with increasing storage capacity and reached a maximum with an increase in residents’ number and a decrease in the roof area. The model enables to determine WSE and RUE for specific storage volumes or to determine the desired WSE and calculate the necessary storage.

scholarly journals Developing Generalised Equation for the Calculation of PayBack Period for Rainwater Harvesting Systems

2021 ◽  
Vol 13 (8) ◽  
pp. 4266
Author(s):  
Monzur A. Imteaz ◽  
Maryam Bayatvarkeshi ◽  
Md. Rezaul Karim
Keyword(s):  
Rainwater Harvesting ◽  
Payback Period ◽  
Rate Of Return ◽  
Power Relationship ◽  
Traditional Practice ◽  
Specific Investment ◽  
Initial Cost ◽  
Harvesting Systems ◽  
Roof Area ◽  
Rainwater Tanks

Many end-users for the stormwater harvesting systems are reluctant in implementing the system due to uncertainties of the potential returns for their investment for such system. A common practice of presenting potential benefit of a certain investment is through calculation of payback period using net annual benefit from the system. Traditional practice of doing such payback period analysis for rainwater tanks was considering individual building/roof, system volume, and specific investment cost. It is not feasible to conduct such analysis for each and every rainwater harvesting system installed in different buildings. To overcome this tedious practice, this study presents development of a generalised equation for the estimation of payback period for rainwater tanks based on roof area, initial cost, and rate of return. Based on an earlier study, several payback periods were calculated for different roof sizes, initial costs, and rate of return. It was found that all these variables can be correlated and embedded into a base equation of power function. Final developed equation results were compared with the payback periods calculated through traditional practice considering net annual savings and net present value of cumulative savings. It is found that the developed equation can estimate payback periods with very good accuracies; for all the selected internal rates of return correlation values ranging from 0.99 to 1.0 were achieved. Corresponding coefficient of determinations varied from 0.988 to 0.993. Furthermore, it is found that for a fixed roof area and rate of return, the payback period is having a power relationship (having an exponent less than 1.0) with the initial cost.

scholarly journals RELIABILITY ANALYSIS OF URBAN RAINWATER HARVESTING

2016 ◽  
Vol 10 (1) ◽  
pp. 124-134
Author(s):  
Dustin Lawrence ◽  
Vicente L. Lopes
Keyword(s):  
Rainwater Harvesting ◽  
Decision Makers ◽  
Period Analysis ◽  
Rainwater Tank ◽  
Property Owners ◽  
Harvesting Systems ◽  
Tank Design ◽  
State And Local ◽  
The Cost ◽  
Multiple Scenarios

The purpose of this study was to inform decision makers at state and local levels, as well as property owners about the amount of water that can be supplied by rainwater harvesting systems in Texas so that it may be included in any future planning. Reliability of a rainwater tank is important because people want to know that a source of water can be depended on. Performance analyses were conducted on rainwater harvesting tanks for three Texas cities under different rainfall conditions and multiple scenarios to demonstrate the importance of optimizing rainwater tank design. Reliability curves were produced and reflect the percentage of days in a year that water can be supplied by a tank. Operational thresholds were reached in all scenarios and mark the point at which reliability increases by only 2% or less with an increase in tank size. A payback period analysis was conducted on tank sizes to estimate the amount of time it would take to recoup the cost of installing a rainwater harvesting system.

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