Water Journal : Water Journal March 2011
industry news regular features 20 MARCH 2011 water Three-month Water Forecasts to Help Water Planners Water managers and planners now have a new tool to give them a better idea of how much water is expected to flow into specific rivers and catchments up to three months ahead. A Seasonal Streamflow Forecast service, developed by CSIRO and the Bureau of Meteorology (the Bureau) in consultation with water managers, was launched in Canberra in December. The forecasts, which will assist decision-making around seasonal water allocation outlooks, reservoir operations, environmental flow management and water markets, are issued monthly and freely on the Bureau's website. Dr Rob Vertessy, Bureau of Meteorology Deputy Director (Climate and Water) said: "Water managers and users now have access to skilful, reliable and robust forecasts of seasonal streamflows. Although there is a lot of water in some areas of Australia at the moment, water availability will continue to vary in the future as demand continues to grow and climate inevitably varies. This poses major challenges for water resource management, so the need to accurately monitor, assess and forecast the availability of water resources is more vital than ever." CSIRO provided the research and development that underpins the forecast service which the Bureau has developed for 13 river sites and eight storages in the south-east Murray- Darling Basin. The service will gradually expand to other locations in Australia over the next 12 to 24 months. The public launch of the forecast service follows a 12-month experimental phase in which the Bureau and CSIRO consulted closely with water organisations. The forecasts use a sophisticated statistical modelling approach, called Bayesian Joint Probability (BJP), to provide information on likely water inflows into major river and storage systems for the three months ahead. The BJP approach forecasts the likelihood of streamflows exceeding various volumes. Forecasts are based on how current catchment conditions and current climate patterns (such as El Niño cycles) influence future catchment runoff and are verified against observed streamflows. The experimental phase showed that the forecasts produced by the BJP approach are skilful, reliable and robust. "The research started only three years ago. To see the research outcome successfully adopted for a new service is amazingly rewarding for CSIRO," said Dr Bill Young, Director of CSIRO's 'Water for a Healthy Country' Flagship. For more information, please go to www.bom.gov.au. New Engineering Technique Reduces Environmental Impact South East Water is applying a new, more environmentally sound, engineering technique to the construction of sewer pump stations. The technique replaces traditional open cut methods and is currently being applied to the upgrade of a sewer pump station on Thornhill Street in Hastings, Victoria. Engineers were able to drill a pump shaft to the exact size required, meaning the resulting excavation site was only five metres in diameter, rather than the 24 metres that would generally be required with open cut methods. The technique not only minimises impacts on local plants and animals, but also lowers the likelihood of destroying archaeological artefacts. "As the new Thornhill Street Sewer Pump Station is located on a site of cultural significance near protected wetlands, South East Water was conscious of developing an engineering solution that would minimise impact and disturbance," said Shaun Cox, South East Water Managing Director. The new pump station is an integral part of the multi-million dollar Somers Recycled Water Project, which will see the production of Class A recycled water for BlueScope Steel's Western Port Plant in Hastings. Jointly funded by the Victorian Government, South East Water and BlueScope Steel, the project is expected to save around 660 million litres of drinking water each year, and reduce the volume of treated water discharged into Western Port Bay by around 280 million litres a year. The engineering technique is a modification to one used at South East Water's Pakenham South Sewer Pump Station earlier this year. As part of the improved construction process, a collapsible hydraulic formwork is lowered into place while the hole is being drilled and concrete is pumped in to form a temporary structure. "The new method enables us to cut our construction time in half. We have also been able to enhance safety for employees as they are not required to enter the excavated hole, as is usually the case," explained Mr Cox. Construction of the Thornhill Street Sewer Pump Station will be completed by mid-year, and it will play a key role in helping to achieve Victorian Government drinking water substitution targets. The new engineering technique being applied by South East Water results in a significantly smaller excavation site and less disturbance to the environment and community.
Water Journal April 2011