Management of water loss in South East Queensland

Country: Australia
Key Area: Water
Services: Asset Management,Water Asset Management

In south east Queensland the combination of rapid population growth and a record breaking drought has reduced reservoirs to critical levels, with total water storage falling to just 18 percent last August. In response, the Queensland State Parliament implemented a number of projects under the Regional Drought Strategy, including the A$90 million south-east Queensland Regional Leakage and Pressure Management Project.

As part of implementing this, Opus has been supporting a number of councils in the region, and in particular it has been providing design services to Redland Water and Waste (RWW).

Redlands is a coastal shire to the south-east of Brisbane with a population of approximately 135,000. It has a diverse character, ranging from rural hinterlands, to the commercial centres of Capalaba and Cleveland, and including Southern Moreton Bay and North Stradbroke islands.

The project requires RWW to implement a system of district metering and pressure management to minimise water losses from its network. Our design team took a ‘source to tap’ approach, dividing the entire network into a total of 31 District Metered Areas, with 15 under pressure management. The network design was developed and tested on planning models to assess the impact on the standards of service for pressure and fire flow, at both current and 2025 planning horizons.

It also required the detailed design and installation of 22 new meters and the refurbishment of six existing installations. Battery operated electro-magnetic meters were selected for ease of installation and to deliver the required combination of low flow accuracy and high turn down ratios.

Pressure management is being delivered using a conventional pilot operated pressure reducing valve. Advanced pressure control (flow modulation) has been applied to allow outlet pressures to be modulated so standards of service can be maintained under a wide range of flow conditions.

Over 100 GSM data loggers have been installed to monitor flow and pressure across the network. Modern GSM technology allows cost effective reporting on a daily basis without the need for manual intervention and can dramatically shorten awareness times in the event of a burst water main. The system not only delivers improved water loss management but also provides a powerful network management tool by allowing engineers to make more informed decisions about day to day network operations.

Work on the mainland network is still on-going however pressure management on some of the Southern Moreton Bay Islands has now been successfully completed, with pressures reduced to their final settings without adverse customer impact. Opus will continue to support RWW as the project is rolled out across the mainland over the next twelve months.