No, not the pressure of water restrictions, rather, Sydney Water is reducing the actual water delivery pressure. Sydney water is guaranteeing a minimum pressure head of 15m, which is 5m head less than the expected available fire demand pressure in publicly available documents published by many water authorities.

The Sunday Telegraph, 10 December 2006 reports, “Sydney Water has begun cutting water pressure for residents and businesses to conserve billions of litres of dwindling drinking supplies.” Reduced water pressure is proved to reduce mains bursts and the flow of continuous leaks, of which Sydney water loses a significant volume of it’s supply to.

With water supplies running at all time lows, the city is requiring drastic measures to manage the sustainability of it’s supply. Of interest to me is the safety and sustainability of a lower water pressure in the event of a fire. Zone management to ensure supply to critical areas in the event of a fire, supply strategies to guarantee supply to hospitals and process specific needs should also be considered.

The average household in Sydney has the attitude that water will be there when and how we need it. The centralized infrastructure and extended large scale network is likely to respond poorly to increased demands and reduced supply. Sydney Water will find it difficult to tell residents that water won’t be available as they’ve come to expect. Security of supply is a real concern in such a centralized scenario as Sydney has, and any measures to reduce demand or stress on infrastructure is a welcome change.

Published by Mike Thomas

Mike Thomas P.Eng. ENV SP, is the author of UrbanWorkbench.com and Director of Engineering at the City of Revelstoke in the Interior of British Columbia, Canada.