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

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.

2018 ◽  
Vol 8 (3) ◽  
pp. 459-467 ◽  
Author(s):  
J. C. Agunwamba ◽  
O. R. Ekwule ◽  
C. C. Nnaji

Abstract Population explosion in urban settings usually exerts enormous pressure on existing water supply systems. The result is that overall water demand is usually not satisfied. This study evaluated the performance of Wadata sub-zone water distribution system with respect to pressure, velocity, hydraulic head loss and nodal demands using WaterCAD and Epanet. There was no statistical difference between the results of Epanet and WaterCAD, however, Epanet produced slightly higher results of pressure and velocity in about 60% of all cases examined. About 19 percent (18.52%) of the total number of nodes analyzed had negative pressures while 69 percent (69%) of the nodes had pressures less than the adopted pressure for the analysis. These negative pressures indicate that there is inadequate head within the distribution network for water conveyance to all the sections. About 88 percent (87.7%) of flow velocities in the pipes were within the adopted velocity while around 12 percent (12.3%) of the velocities exceeded the adopted velocity. These excess velocities are partly responsible for the leakages and pipe bursts observed at some points within the system. The results in this study revealed that the performance of the water distribution system of Wadata sub-zone under current demand is inefficient.


2017 ◽  
Vol 18 (1) ◽  
pp. 214-221
Author(s):  
K. L. Lam ◽  
P. A. Lant ◽  
S. J. Kenway

Abstract During the Millennium Drought in Australia, a wide range of supply-side and demand-side water management strategies were adopted in major southeast Australian cities. This study undertakes a time-series quantification (2001–2014) and comparative analysis of the energy use of the urban water supply systems and sewage systems in Melbourne and Sydney before, during and after the drought, and evaluates the energy implications of the drought and the implemented strategies. In addition, the energy implications of residential water use in Melbourne are estimated. The research highlights that large-scale adoption of water conservation strategies can have different impacts on energy use in different parts of the urban water cycle. In Melbourne, the per capita water-related energy use reduction in households related to showering and clothes-washing alone (46% reduction, 580 kWhth/p/yr) was far more substantial than that in the water supply system (32% reduction, 18 kWhth/p/yr). This historical case also demonstrates the importance of balancing supply- and demand-side strategies in managing long-term water security and related energy use. The significant energy saving in water supply systems and households from water conservation can offset the additional energy use from operating energy-intensive supply options such as inter-basin water transfers and seawater desalination during dry years.


Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2606
Author(s):  
Preeti Preeti ◽  
Ataur Rahman

This paper presents reliability, water demand and economic analysis of rainwater harvesting (RWH) systems for eight Australian capital cities (Adelaide, Brisbane, Canberra, Darwin, Hobart, Melbourne, Perth and Sydney). A Python-based tool is developed based on a daily water balance modelling approach, which uses input data such as daily rainfall, roof area, overflow losses, daily water demand and first flush. Ten different tank volumes are considered (1, 3, 5, 10, 15, 20, 30, 50, 75 and 100 m3). It is found that for a large roof area and tank size, the reliability of RWH systems for toilet and laundry use is high, in the range of 80–100%. However, the reliability for irrigation use is highly variable across all the locations. For combined use, Adelaide shows the smallest reliability (38–49%), while Hobart demonstrates the highest reliability (61–77%). Furthermore, economic analysis demonstrates that in a few cases, benefit–cost ratio values greater than one can be achieved for the RWH systems. The findings of this study will help the Australian Federal Government to enhance RWH policy, programs and subsidy levels considering climate-sensitive inputs in the respective cities.


2020 ◽  
Vol 15 (3) ◽  
pp. 035007 ◽  
Author(s):  
Elisabeth H Krueger ◽  
Dietrich Borchardt ◽  
James W Jawitz ◽  
P Suresh C Rao

2018 ◽  
Vol 110 (2) ◽  
pp. 40-47 ◽  
Author(s):  
Brian D. Richter ◽  
Mary Elizabeth Blount ◽  
Cara Bottorff ◽  
Holly E. Brooks ◽  
Amanda Demmerle ◽  
...  

2020 ◽  
Vol 10 (22) ◽  
pp. 8219
Author(s):  
Andrea Menapace ◽  
Ariele Zanfei ◽  
Manuel Felicetti ◽  
Diego Avesani ◽  
Maurizio Righetti ◽  
...  

Developing data-driven models for bursts detection is currently a demanding challenge for efficient and sustainable management of water supply systems. The main limit in the progress of these models lies in the large amount of accurate data required. The aim is to present a methodology for the generation of reliable data, which are fundamental to train anomaly detection models and set alarms. Thus, the results of the proposed methodology is to provide suitable water consumption data. The presented procedure consists of stochastic modelling of water request and hydraulic pipes bursts simulation to yield suitable synthetic time series of flow rates, for instance, inlet flows of district metered areas and small water supply systems. The water request is obtained through the superimposition of different components, such as the daily, the weekly, and the yearly trends jointly with a random normal distributed component based on the consumption mean and variance, and the number of users aggregation. The resulting request is implemented into the hydraulic model of the distribution system, also embedding background leaks and bursts using a pressure-driven approach with both concentrated and distributed demand schemes. This work seeks to close the gap in the field of synthetic generation of drinking water consumption data, by establishing a proper dedicated methodology that aims to support future water smart grids.


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