This report was prepared to present the findings of a year-long research thesis undertake by Rhys Cullen, a final year Environmental Engineering student at the University of Queensland. The study applied an accepted method of quantifying leak sensitivity, the Fixed and Variable Area Discharge concept to elements of domestic consumption. In particular this study was focussed on irrigation systems.
The sensitivity of six different types of irrigation systems or devices were tested at a range of operating pressures, and their discharge behaviour recorded. Applying FAVAD to these results generated a sensitivity value for each device.
The devices to be tested were split into two categories, rigid and non-rigid for the purpose of further analysis. It was found that non-rigid devices are more sensitive to pressure than rigid devices, mainly due to the expandable nature of flexible devices discharge paths.
These results led to a number of observations, including the large amounts of excess water discharged by irrigation systems overnight, during periods of high nightflow pressures. A number of recommendations and conclusions were drawn from these observations, regarding on-site irrigation consumption reduction and zone-wide reductions that Water Authorities may further investigate.