A study on the effects of intermittent water supply on the vulnerability of urban water distribution networks

Abstract

Faced with extended periods of drought and short supply of water, arid-weather countries have turned to intermittent water supply (IWS) as a means to reduce water consumption and to prolong their national water reserves. Unfortunately, such drastic measures usually fail to consider the effects of intermittent supply on the condition of piping networks and the resulting water losses, inefficiencies and overall maintenance cost on these networks. Presented herein is research work on the effects of IWS on the vulnerability of urban water distribution networks (UWDN) based on a 3-year dataset from major urban centres in Cyprus. The dataset includes information on breakage incidents, operating network parameters, external factors and vulnerability assessment and by use of data-mining and survival analysis techniques evaluates the effects of such intermittent supply strategies on the vulnerability of the water pipes and on the sustainability of the strategy.

Intermittent Domestic Water Supply: A Critical Review and Analysis of Causal-Consequential Pathways

“…This contributes to water loss from the network [22,88]; poor data management on the part of the utility, which is unable to track where the water goes [76,123]; and poor water quality [43]. Private connections are often the end result of consumers' individual decisions make private investments in obtaining water [6,34]. One way to avoid private connections would be to provide adequate connections to households in the network area.…”

“…The conditions in Table 2 show the many costs of intermittent water, including those to the infrastructure and the management system, as well as to consumers themselves. Intermittent supply degrades infrastructure and imposes additional management responsibilities [34].…”

“…But these terms are not used consistently. For example, one researcher describes intermittent water arriving during a 24 h period is an unreliable supply [116], although for [34], water arriving for less than 24 h a day (but within a given 24 h period) is intermittent. Others define intermittency as water arriving at intervals of hours, days, or weeks [21,35].…”

Optimizing Intermittent Water Supply in Urban Pipe Distribution Networks

“…With field data from urban India, Kumpel and Nelson [18] quantified the deleterious effect of intermittency on water quality, showing that both the initial flushing of water through empty pipes-as well as periods of low pressure-corresponded with periods of increased turbidity and bacterial contamination. Christodoulou [7] observed when that a drought in Cypress ushered in two years of intermittent supply, pipe ruptures increased by 30%-70% per year.Whereas intermittent water supply creates challenges for water managers and water users, the phenomenon creates opportunities for applied mathematics. It is an interesting and difficult mathematical problem to efficiently model transient pipe flow in networks-including transitions to and from pressurized states-with uncertain or complex boundary conditions.…”

“…With field data from urban India, Kumpel and Nelson [18] quantified the deleterious effect of intermittency on water quality, showing that both the initial flushing of water through empty pipes-as well as periods of low pressure-corresponded with periods of increased turbidity and bacterial contamination. Christodoulou [7] observed when that a drought in Cypress ushered in two years of intermittent supply, pipe ruptures increased by 30%-70% per year.…”