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Background for Five Water Projects for Numurkah 16 April 2009 Strategy Development In 2007 Goulburn Valley Water completed a Water Treatment Master Plan for Numurkah and in 2008 a Water Pipe Network Master Plan was completed. Both these master plans addressed the future growth of Numurkah and Wunghnu. The growth rates used in the master plans are based on Victoria In Future Projections developed by the Department of Sustainability and Environment.
The growth rates equate to an additional 400 residential connections over the next 20 years. In addition to the residential and commercial growth, an increase in industrial water usage is expected over the next five years. Water Treatment Master Plan The Numurkah Water Treatment Plant (WTP) receives its raw water supply directly from the Broken Creek. The raw water quality can be highly variable and is subject to rapid change following rainfall. During the irrigation shutdown period (mid May to mid August) flows in the Broken Creek at Numurkah are limited to rainfall runoff upstream in the Broken Creek catchment. Flows are often very low during winter and sandbagging of a weir in the Creek is regularly required during this period to maintain supply to the raw water pump station. The Water Treatment Master Plan highlighted the need to improve water quality, supply security and the capacity of the water treatment plant. Options that were considered to develop the master plan are listed below: Alternative raw water supply sources considered were:
Alternative water treatment plant upgrade options considered were:
Construction of additional treated water storage was included in all options. The outcome of the master plan was the identification of a raw water storage project, treated water storage tank project and water treatment plant upgrade project. Raw Water Storage A raw water storage will enable raw water of a consistent quality to be supplied to the Numurkah WTP and will provide additional supply security during Winter. This project will involve the construction of a 280 megalitre earthen storage north of Numurkah which will receive raw water from the Murray Valley irrigation channel system. Water will be pumped from the raw water storage to the existing water treatment plant in the town. This project will provide improved supply security and improved raw water quality. The raw water storage will be of a suitable size to maintain supply during the annual shutdown period for the irrigation channel network. GVW will be completing investigations to identify a suitable site north of the town. Key requirements of a suitable site will be soil conditions, located outside of the flood overlay, located near an irrigation channel with available capacity and located outside of the urban growth boundary. Total Project Cost of $4.98M Could the Numurkah Lake be used as the Raw Water Storage? The construction of a raw water storage will provide improved raw water quality for the Numurkah water treatment plant. To ensure that the full water quality benefit is received from the raw water storage it should be in a secure location with contamination risks minimised. GVW is required to minimise contamination risks in accordance with the Safe Drinking Water Act. The Numurkah Lake is used for recreational purposes and has significant bird populations permanently around the Lake. The current recreational use of the Lake and the bird population are not compatible with the requirements to minimise contamination risks for a drinking water supply under the Safe Drinking Water Act. The Lake is also smaller than the required size of 280 megalitre for the raw water storage. Treated Water Storage Tank This project will involve the construction of a 3 megalitre roofed storage tank on vacant land at the existing water treatment plant. There is currently a 1.3 megalitre storage tank at the facility and a 1.0 megalitre storage tank across the road, next to the Broken Creek. This project will increase the volume of treated water storage that is available to a minimum of 8 hours supply at all times (currently minimum of 4 hours available). This will provide improved supply security for Numurkah and Wunghnu. Total Project Cost of $1.92M Water Treatment Plant Upgrade The upgrade to the water treatment plant will increase the capacity to 10 megalitres per day – the existing capacity is 7.5 megalitres per day. The upgrade will provide capacity for future growth in the town. The upgrade can be constructed at either the existing facility in Numurkah or at the raw water storage site. The exact works and technology adopted for the upgrade will be dependent on which site is chosen. Community engagement will be undertaken in future to obtain social inputs to the decision on the location for the upgrade. The location for the upgrade will be decided on a triple bottom line basis taking into account economic, environmental and social considerations. Total Project Cost of $4.35M The timing for the projects is summarised as follows:
Authorised By P.A. Quinn, 104-110 Fryers Street Shepparton
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Copyright
2009 Goulburn Valley Water 104-110 Fryers Street, Shepparton, Victoria, Australia DX 63036, P.O. Box 185, Shepparton 3632, Australia P: +61 3 5832 0400 F: +61 3 5831 1467 E: mail@gvwater.vic.gov.au |
