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The deterioration of water mains is taking its toll on water utilities across theworld. It is imperative that this deterioration be accurately quantified in order toimplement effective renewal plans for water distribution systems. With hundreds and eventhousands of buried pipes, it is often prohibitively expensive to directly inspect every watermain in a distribution network. Identifying water main breakage patterns over time is aneffective and inexpensive alternative to measuring the structural deterioration of a waterdistribution system.Breakage rates of water mains are affected by many factors that are pipe-intrinsic, environmentaland operational. An effective water main renewal plan must consider future breakagerates and to forecast breakage rates one must identify the "true" backgrounddeterioration rates of the water mains, and quantify the impact of variousenvironmental factors as well as operational strategies on future breakage rates. TheNational Research Council of Canada is developing a prototype computer application tohelp model the deterioration rates of water mains and subsequently plan their renewal. Itconsiders time-dependent factors such as temperature (in the form of freezing index), soilmoisture (in the form of rainfall deficit), main replacement rates and cathodic protection(CP) strategies, including hotspot CP as well as systematic retrofit CP. Non-time dependent(or static) factors such as pipe characteristics and soil type are consideredthrough water main grouping.The background aging rates of water mains enable the projection of their future breakagerates. In addition, the impact of operational strategies such as schedules of cathodicprotection (both hotspot and retrofit) and pipe replacement can be superimposed on thisbackground aging. Subsequently, the life cycle costs of various scenarios of operationalstrategies can be evaluated and fine-tuned to achieve maximum efficiency in resourceallocation. Further, because the impact of time-dependent climatic conditions is quantifiedas well, planners can obtain climate forecasts from the weather bureau (no more that 2-4years recommended) to evaluate expected year to year variations in the breakage rates. Includes 6 references, figures.

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Edition: Vol. - No. Published: 06/15/2003 Number of Pages: 12File Size: 1 file , 600 KB