Appendix B:Water Leakage Issues and BackgroundBecause water and <strong>energy</strong> are basic requirements of life, and their use figures so prom<strong>in</strong>ently<strong>in</strong> contemporary society, it is no wonder that one may appropriately perceive both thewater supply and <strong>energy</strong> networks as the bedrock of civil <strong>in</strong>frastructure. While easilytaken for granted, their vital importance is readily acknowledged when suddenly faced witha profound failure. News events can quickly rem<strong>in</strong>d us of our dependence on these usuallysteadfast and silent facilitators of our economic, social and material well be<strong>in</strong>g. Fortunately,acute and celebrated failures such as these have not hitherto occurred with alarm<strong>in</strong>g frequency,but when they do happen, they are often accompanied by a soul search<strong>in</strong>g re-exam<strong>in</strong>ation ofthe state of these systems and bold pronouncements of a renewed dedication to preserve andma<strong>in</strong>ta<strong>in</strong> our <strong>in</strong>frastructure. <strong>The</strong> danger with such reactive measures, though, is that decisionscan be made that are visible and immediate <strong>in</strong> impact, and not necessarily those that are thewisest and most strategic <strong>in</strong> the long term.In general, Canadian municipal water distribution systems (WDS) provide a high level ofservice with amaz<strong>in</strong>g regularity. This be<strong>in</strong>g the case, is there reason for any serious concern?Curiously, while spectacular failures occasionally push matters to the forefront, it is the dayto-dayoperation of such <strong>in</strong>frastructure that may entail the greatest economic, social andenvironmental burdens. Ongo<strong>in</strong>g <strong>in</strong>efficiency has a greater impact on total water and <strong>energy</strong>resource use as well as the f<strong>in</strong>ancial burden of operat<strong>in</strong>g the <strong>in</strong>frastructure than do <strong>in</strong>frequent,but large events. Unwanted consequences associated with wasted <strong>energy</strong> <strong>in</strong> these systems<strong>in</strong>clude needless emissions of greenhouse gases (GHGs) which are responsible for encourag<strong>in</strong>ganthropogenic climate change and other atmospheric pollutants that <strong>in</strong>duce smog, ozonedepletion, and acid precipitation. Occupational hazards related to the production, generationand use of <strong>energy</strong> such as coal m<strong>in</strong>e explosions, oil spills and the compromised health ofworkers <strong>in</strong> the <strong>energy</strong> sector are <strong>in</strong>directly <strong>in</strong>creased <strong>in</strong> some measure when more <strong>energy</strong> isused and wasted. As <strong>in</strong>frastructure ages and deterioration <strong>in</strong>troduces new sources of <strong>energy</strong><strong>in</strong>efficiency while exacerbat<strong>in</strong>g old ones, the already tight fiscal resources of most Canadianmunicipalities are put under further pressure. At the moment, for example, prov<strong>in</strong>ces aregrappl<strong>in</strong>g with the problem of underfunded health care and educational systems. Money lostdue to poorly perform<strong>in</strong>g <strong>in</strong>frastructure, and <strong>in</strong>adequately planned <strong>in</strong>frastructure <strong>in</strong>vestment,entails an opportunity cost s<strong>in</strong>ce these funds could be applied elsewhere, either for moreeffective <strong>in</strong>frastructure renewal and repair or other endeavours that serve a higher societal<strong>in</strong>terest like public assistance, education or support for culture.<strong>The</strong> activities <strong>in</strong>volved <strong>in</strong> the design, construction, operation and ma<strong>in</strong>tenance of WDSform a network of <strong>in</strong>terrelated processes that could be thought of as a labyr<strong>in</strong>th, perhapssuch as that depicted <strong>in</strong> Figure 1. Although even a cursory description of the contents ofFigure 1 is beyond the limitations of this report, a few elements deserve brief mention here.As presented, the labyr<strong>in</strong>th is anchored by three fundamental components. <strong>The</strong> demandfor water establishes the need for the system <strong>in</strong> the first place and is itself derived from avariety of factors <strong>in</strong>clud<strong>in</strong>g basic life necessity, socio-economic <strong>in</strong>fluences and climate. <strong>The</strong>quantification of this demand determ<strong>in</strong>es how much, and what k<strong>in</strong>d of, capacity is required,directly <strong>in</strong>fluenc<strong>in</strong>g decisions about <strong>in</strong>vestments <strong>in</strong> pipes, pumps, reservoirs and treatment30 <strong>rccao</strong>.com
plants. <strong>The</strong> capacity of the system is determ<strong>in</strong>ed by physical attributes of the <strong>in</strong>frastructure(pipes, tanks, reservoirs, pumps) and <strong>in</strong>corporates <strong>in</strong>stalled, reserve, pump<strong>in</strong>g and treatmentcapacities. Current capacity reflects past <strong>in</strong>vestments and deteriorations while future capacityreflects current system augmentation and rehabilitation decisions. <strong>The</strong> fit between demand andcapacity def<strong>in</strong>es overall performance.Energy Loss Mechanisms<strong>The</strong>re are several <strong>energy</strong> loss mechanisms <strong>in</strong> water distribution systems (WDS). Somemechanisms, like friction and pump selection, are well recognized and have been studiedextensively, while others, such as breaks, most types of blockage, repair and replacementoperations, and leaks have been <strong>in</strong>adequately characterized, as have been the <strong>in</strong>teraction ofthe various subsystems. <strong>The</strong>se less well-appreciated sources of <strong>energy</strong> loss need to be betterunderstood, with each source of <strong>in</strong>efficiency be<strong>in</strong>g placed <strong>in</strong>to relative context (see Figure 2).Fig. 1: <strong>The</strong> Labyr<strong>in</strong>th of Water Distribution Systems (from Colombo and Karney, 2003)<strong>Incorporat<strong>in</strong>g</strong> <strong>Susta<strong>in</strong>ability</strong> <strong>in</strong> <strong>Infrastructure</strong> <strong>ROI</strong> 31
Change language