Assessing theeffect of pressure reduction on losses from water distribution systems

Report No WSAA 5

December 1989




The research project was to assess the effectivenessof a control valve which reduces the operating pressure in a water distributionsystem as the flow requirement decreases, thus minimising watermain breaks andreducing leakage losses.


A pressure control valve system was installed tocontrol a discrete part of the distribution system serving about 2,000 people inthe township of Raymond Terrace, NSW.


Losses from the zone were assessed prior tocommencing the project, using typical night flow procedures and, after thecontrol valve was installed, by recorded flows and pressures. Effect on systemperformance was monitored and can be shown to have achieved the objective ofreducing maximum system pressures, night flows (lowest flow periods) and thenumber of watermain breaks within the zone.


A benefit/cost analysis for the project wasdetermined and resulted in a ratio of 1.6/1.0 over a ten year period, based onwatermain breaks prior to and after commissioning of the valve.


Resulting benefits from reduced system losses andflows can be applicable with similar installations throughout the waterindustry in general.



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