Examination into the Reliability of Seconday Water Supplies

Secondary water supplies have been included within the standard due to their perceived increase in the reliability of the water supplied to the sprinkler system, however, the decision on which secondary water supply best fits a building or region has not been adequately researched. By deriving the availability of the water supply, the different solutions covered by the New Zealand Standards can be compared. The methodology considers the major influences on the reliability of a water supply headworks as well as the infrastructure involved in the secondary water supplies. In order to assess the reliability of these systems, critical components within the system need to be identified. Comprehensive data collected for all the critical components of the water supply are analysed to obtain a comparison of the reliability of secondary water supplies. A Monte Carlo simulation is then used to generate random failures. These failure can be used to examine the reliability of the water supply. The probabilities found during this examination confirm the additional reliability found in dual supply. It also shows that there are large variations in the reliability of the supply depending on the source of the town‟s mains supply. Current literature describing the reliability of water supplies is examined and a case study of the Adelaide headworks is conducted showing the compatibility of the calculated values to those found within the literature