Rainwater harvesting as an alternative for water supply in regions with high water stress

Abstract In this study, the reliability of using rainwater harvesting to cover the water demand of a transportation logistics company located in Mexico City was assessed. Water consumption in facilities and buildings of the company was determined. Rainwater potentially harvestable from the roofs and maneuvering yard of the company was estimated based on a statistical analysis of the rainfall. Based on these data, potential water saving was determined. Characterization of rainwater was carried out to determine the treatment necessities for each water source. Additionally, the capacity of water storage tanks was estimated. For the selected treatment systems, an economic assessment was conducted to determine the viability of the alternative proposed. Results showed that current water demand of the company can be totally covered by using rainwater. The scenario where roof and maneuvering yard rainwater was collected and treated together resulted in being more economic than the scenarios where roof and maneuvering yard rainwater was collected and treated separately. Implementation of the rainwater harvesting system will generate important economic benefits for the company. The investment will be amortized in only 5 years and the NPV will be on the order of US$ 5,048.3, the IRR of 5.7%, and the B/I of 1.9.

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Techno-Economic and Sensitivity Analysis of Rainwater Harvesting System as Alternative Water Source

Sustainability ◽

10.3390/su11082365 ◽

2019 ◽

Vol 11 (8) ◽

pp. 2365 ◽

Cited By ~ 9

Author(s):

Pg Emeroylariffion Abas ◽

TMI Mahlia

Keyword(s):

Performance Measures ◽

Economic Performance ◽

Rainwater Harvesting ◽

Water Source ◽

High Water ◽

Capital Cost ◽

Water Price ◽

Current Water ◽

Alternative Water ◽

The Cost

This paper formulates a rainwater harvesting model, with system and economic measures to determine the feasibility of a rainwater harvesting system, which uses water from the mains to complement the system. Although local meteorological and market data were used to demonstrate the model, it can also be easily adapted for analysis of other localities. Analysis has shown that an optimum tank size exists, which minimizes the cost per unit volume of water. Economic performance measures have indicated that rainwater harvesting system is currently infeasible to be implemented in Brunei; with capital cost and water price being shown to be among the prohibiting factors. To improve feasibility, a combination of rebate scheme on capital cost and raising the current water price has been proposed. It has also been shown that the system is more viable for households with high water demand.

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

Hydrology ◽

10.3390/hydrology8010009 ◽

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.

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Socioeconomic potential for rainwater harvesting systems in southern Brazilian municipalities

Water Science & Technology Water Supply ◽

10.2166/ws.2021.291 ◽

2021 ◽

Author(s):

L. C. Tavares ◽

J. M. Bravo ◽

R. Tassi ◽

I. R. Almeida ◽

D. Wartchow

Keyword(s):

Rainwater Harvesting ◽

High Water ◽

Economic Benefits ◽

Point Of View ◽

Technology Selection ◽

Domestic Water ◽

Water Demands ◽

Harvesting Systems ◽

Residential Demand ◽

Economic Constraints

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 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 reflected in higher economics savings. The advantages of using the RWH systems outstand even more when the investments at Federal and Local levels are considered.

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Multi-method efficiency analysis of Rainwater Harvesting Systems in Corredor Seco region, Central America

10.5194/egusphere-egu2020-16844 ◽

2020 ◽

Author(s):

Elena Bresci ◽

Giulio Castelli ◽

Nadia Ursino ◽

Antonio Giacomin ◽

Federico Preti

Keyword(s):

Rainwater Harvesting ◽

Smallholder Farmers ◽

Water Source ◽

Extreme Weather Events ◽

Rainfall Time Series ◽

Vegetable Production ◽

Water Harvesting ◽

Storage Tanks ◽

Balanced Diet ◽

Harvesting Systems

The region of Corridor Seco (Dry Corridor, including parts of Guatemala, Honduras and El Salvador) has been facing multiple food crises caused by extreme weather events, water scarcity and land degradation phenomena. In this situation, Rooftop Water Harvesting (RWH) systems can effectively enhance local livelihoods, especially in marginalized communities, by providing an additional water source for domestic use, livestock, and irrigation of small horticultural plots which are key for vegetable production and thus for vitaminic input in a well-balanced diet.Dimensioning sufficient storage tanks for rainwater collection is key, since smallholder farmers&#8217; capabilities are often hindered by low financial capacity as well as by limited land extension for reservoir building.Efficiency of storage tanks and design criteria for water harvesting systems are investigated on the base of rainfall time series analysis, probabilistic risk assessment and Monte Carlo simulation (Ursino, 2016). The approach is tested on a series of (RWH) systems built in Guatemalan part of the Corredor Seco, Chiquimula department, with sustainable and appropriate building techniques, but with variable size due to the variability of each household. Factors affecting efficiency of storage tanks are discussed to inform future sustainable water management planning in the area.Reference:Ursino, N. Risk Analysis Approach to Rainwater Harvesting Systems. Water 2016, 8, 337. https://doi.org/10.3390/w8080337

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Is Rainwater Harvesting Sufficient to Satisfy The Emergency Water Demand for The Prevention of COVID-19? The Case of Dilla town, Southern, Ethiopia

10.20944/preprints202008.0721.v2 ◽

2020 ◽

Author(s):

Girum Gebremeskel Kanno ◽

Zemachu Ashuro Lagiso ◽

Zeleke Girma Abate ◽

Abereham Shiferaw Areba ◽

Renay Van Wyk ◽

...

Keyword(s):

Water Demand ◽

Rainwater Harvesting ◽

Water Source ◽

Maximum Error ◽

Rain Water ◽

Annual Rainfall ◽

Southern Ethiopia ◽

Water Harvesting ◽

Alternative Water ◽

The Town

Rainwater harvesting could be an optional water source to fulfil the emergency water demand in different setups. The aim was to assess if the rainwater harvesting potential for households and selected institutions were sufficient to satisfy the emergency water demand for the prevention of COVID-19 in Dilla town, Southern, Ethiopia. Rain water harvesting potential for households and selected institutions were quantified using 17 years’ worth of rainfall data from Ethiopian Metrology Agency. With an average annual rainfall of 1464 mm, households with 40 and 100 m2 roof sizes have a potential to harvest between 15.71-31.15 m3 and 41.73-82.73 m3 of water using Maximum Error Estimate. Meanwhile 7.2-39.7 m3 and 19.11-105.35 m3 of water can be harvested from the same roof sizes using Coefficient of Variation for calculation. Considering mean monthly rainfall, the health centres and Dilla University can attain 45.7% and 77% of their emergency water demand, while the rest of the selected institutions in Dilla Town can attain more than 100 % of their demand using only rainwater. Rain water can be an alternative water source for the town in the fight against COVID-19.

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Is Rainwater Harvesting Sufficient to Satisfy The Emergency Water Demand for The Prevention of COVID-19? The Case of Dilla town, Southern, Ethiopia

10.20944/preprints202008.0721.v1 ◽

2020 ◽

Author(s):

Girum Gebremeskel Kanno ◽

Zemachu Ashuro Lagiso ◽

Zeleke Girma Abate ◽

Abereham Shiferaw Areba ◽

Renay Van Wyk ◽

...

Keyword(s):

Water Demand ◽

Rainwater Harvesting ◽

Water Source ◽

Maximum Error ◽

Rain Water ◽

Annual Rainfall ◽

Southern Ethiopia ◽

Water Harvesting ◽

Alternative Water ◽

The Town

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Removal of Hydrophobic and Hydrophilic Constituents by Anion Exchange Resin

Water Science & Technology ◽

10.2166/wst.1999.0478 ◽

1999 ◽

Vol 40 (9) ◽

pp. 207-214 ◽

Cited By ~ 35

Author(s):

J.-P. Croué ◽

D. Violleau ◽

C. Bodaire ◽

B. Legube

Keyword(s):

Molecular Weight ◽

Anion Exchange ◽

Water Source ◽

Atomic Ratio ◽

Size Exclusion ◽

Salting Out ◽

Anion Exchange Resins ◽

Hydrophilic Character ◽

Exchange Resins

The objective of this work was to compare the affinity of well characterized NOM fractions isolated from two surface waters with strong (gel matrix and macroporous matrix) and weak anion exchange resins (AER) using batch experiment conditions. The structural characterization of the fraction of NOM has shown that the higher the hydrophilic character, the lower the C/O atomic ratio, the lower the SUVA, the lower the aromatic carbon content and the lower the molecular weight. In general (not always), strong AER was more efficient to remove DOC than weak AER. For the same water source (Suwannee River), the higher the molecular weight of the NOM fraction, the lower the affinity with AER. Increasing the ionic strength favored the removal of the hydrophobic NOM fraction (“salting out” effect) while increasing the pH apparently reduced the removal of the hydrophilic NOM fraction. Results were discussed in terms of size exclusion, adsorption, anion exchange and also hydrophobic/hydrophilic repulsion.

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Optimal Sizing of Rooftop Rainwater Harvesting Tanks for Sustainable Domestic Water Use in the West Bank, Palestine

Water ◽

10.3390/w13040573 ◽

2021 ◽

Vol 13 (4) ◽

pp. 573

Author(s):

Sameer Shadeed ◽

Sandy Alawna

Keyword(s):

Storage Tank ◽

Rainwater Harvesting ◽

West Bank ◽

Family Members ◽

Optimal Size ◽

Storage Tanks ◽

Domestic Water ◽

The West ◽

Average Family ◽

Rooftop Rainwater Harvesting

In highly water-poor areas, rooftop rainwater harvesting (RRWH) can be used for a self-sustaining and self-reliant domestic water supply. The designing of an optimal RRWH storage tank is a key parameter to implement a reliable RRWH system. In this study, the optimal size of RRWH storage tanks in the different West Bank governorates was estimated based on monthly (all governorates) and daily (i.e., Nablus) inflow (RRWH) and outflow (domestic water demand, DWD) data. In the estimation of RRWH, five rooftop areas varying between 100 m2 and 300 m2 were selected. Moreover, the reliability of the adopting RRWH system in the different West Bank governorates was tested. Two-time series scenarios were assumed: Scenario 1, S1 (12 months, annual) and scenario 2, S2 (8 months, rainy). As a result, reliable curves for preliminary estimation of optimal RRWH storage tanks for the different West Bank governorates were obtained. Results show that the required storage tank for S1 (annual) is more than that of the S2 (rainy) one. The required storage tank to fulfill DWD is based on the average rooftop area of 150 m2, the average family members of 4.8, and the average DWD of 90 L per capita per day (L/c/d) varies between (75 m3 to 136 m3) and (24 m3 to 84 m3) for S2 for the different West Bank governorates. Further, it is found that the optimal RRWH tank size for the 150 m2 rooftop ranges between 20 m3 (in Jericho) to 75 m3 (in Salfit and Nablus) and between 20 m3 (in Jericho) to 51 m3 (in Jerusalem) for S1 and S2 scenarios, respectively. Finally, results show that the implementation of an RRWH system for a rooftop area of 150 m2 and family members of 4.8 is reliable for all of the West Bank governorates except Jericho. Whereas, the reliability doesn’t exceed 19% for the two scenarios. However, the reduction of DWDv is highly affecting the reliability of adopting RRWH systems in Jericho (the least rainfall governorate). For instance, a family DWDv of 3.2 m3/month (25% of the average family DWDv in the West Bank) will increase the reliability at a rooftop area of 150 m2 to 51% and 76% for S1 and S2, respectively.

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