Research Library All other publications Research Publications 2-2010 Water Management Plan for the Town of Perenjori Mark Pridham Follow this and additional works at: https://researchlibrary.agric.wa.gov.au/pubns Part of the Environmental Monitoring Commons, Hydrology Commons, and the Water Resource Management Commons Recommended Citation Pridham, M. (2010), Water Management Plan for the Town of Perenjori. Department of Primary Industries and Regional Development, Western Australia, Perth. Report. This report is brought to you for free and open access by the Research Publications at Research Library. It has been accepted for inclusion in All other publications by an authorized administrator of Research Library. For more information, please contact [email protected]. Water Management Plan for the Town of Perenjori February 2010 Acknowledgements Thank you to all those who contributed to this Water Management Plan. This project was made possible through State and Commonwealth Government funding, some of the investment being determined by the Northern Agricultural Catchment Council. Funding and technical assistance was also provided by the council and staff of the Perenjori Shire. The water management report was prepared by Ceidwen Pengelly of the Department of Agriculture and Food, Western Australia (DAFWA) as part of DAFWA’s ‘Rural Towns – Liquid Assets’ Project. Supporting technical reports and appendices were contributed by Bob Paul, Chris Boyes and Russell Speed (DAFWA), Jeff Turner, Olga Barron, Andrew Grant, Ashok Sharma and others from the CSIRO, Peter McCafferty, Jenny McGuire (Chemistry Centre), Jo Pluske, Kate Shearer (UWA) and Paul Wilkes (Curtin University). The stormwater design services were provided by Geoff Love, Garrick Yandle and others from GHD Consultants. The document was edited and produced by Mark Pridham, DAFWA. Disclaimer The Chief Executive Officer of the Department of Agriculture and Food and the State of Western Australia accept no liability whatsoever by reason of negligence or otherwise arising from the use or release of this information or any part of it. Copyright © Western Australian Agriculture Authority, 2009 Copies of this document are available in alternative formats upon request. 3 Baron-Hay Court, South Perth WA 6151 Tel: (08) 9368 3333 Email: [email protected] www.agric.wa.gov.au/RTLA Water Management Plan for the Town of Perenjori Contents Page Summary ....................................................................................................................................... ii 1. Introduction ........................................................................................................................ 1 1.1 Background ................................................................................................................ 1 1.2 Water Management Objectives ................................................................................. 1 1.3 Purpose of the Water Management Plan .................................................................. 2 1.4 Summary of the Issues .............................................................................................. 3 2. Current Town Status .......................................................................................................... 5 2.1 Biophysical Environment ........................................................................................... 5 2.2 Townsite Water Management Problems .................................................................... 6 2.3 Groundwater Quality .................................................................................................. 6 2.4 Town Water Use ........................................................................................................ 6 2.5 Investigations ............................................................................................................. 8 2.6 Urban Water ............................................................................................................... 11 2.7 Town Water Resources ............................................................................................. 12 2.8 Socio-Economic Factors ............................................................................................ 13 3. Water Management Recommendations (Options) .......................................................... 13 High Priority Options ............................................................................................................ 13 Options ................................................................................................................................. 13 Other Options ....................................................................................................................... 14 4. Analysis Of Water Management Options ......................................................................... 17 4.1 Scheme Water Consumption ..................................................................................... 17 4.2 Existing Irrigation Water Supplies – Shire Dams ....................................................... 17 5. Conclusions ........................................................................................................................ 19 6. References .......................................................................................................................... 19 7. Appendices ......................................................................................................................... 19 i Water Management Plan for the Town of Perenjori Summary The Rural Towns – Liquid Assets (RT–LA) project was established with the aim of integrating salinity, waterlogging and flooding control with development of new water supplies in wheatbelt towns, and where possible, finding ways of putting the excess water to commercial use. Following the identification of effective integrated water management strategies, these have been applied to the 15 Shires participating in the DAFWA led RT–LA project. This report summarises the outcomes from all scientific investigations undertaken for Perenjori. In addition it presents the water management options, a preliminary analysis of those options and the priority recommended ones. Due to the decline in rainfall over the past 10 years, Perenjori groundwater levels have shown a declining trend below the townsite since 2000, when groundwater monitoring by DAFWA in the townsite commenced. Hydrogeological studies identified groundwater pumping was not an effective solution for Perenjori to control watertable levels in the high salinity risk areas of the townsite. The studies demonstrated that only limited volumes of groundwater could be abstracted by pumping because the drawdown affects would be constrained by the geological properties. It is concluded that salinity control or water production from under the townsite via groundwater pumping is not a technically viable option. Instead, the RT–LA project has focused on surface water management options that will enable new water supplies to be developed which will also alleviate salinity, watertable, waterlogging and flooding problems. An integrated scheme such as this will provide cost effective solutions to the annual problem of irrigation water shortages. Over time, the proposed surface water diversion and harvesting schemes will reduce salinity risk by diverting and utilising runoff water which would otherwise have contributed to local recharge. Option 1, construction of a new 30ML dam in the paddock east of town belonging to Mr Jim Gilmour, is recommended as the first priority action. Along with the other options outlined in this Water Management Plan, Option 1 offers a combination of surface water engineering solutions to capture the town’s runoff and provide up to an additional 31 ML/yr, or 155 per cent of the total existing demand. ii Water Management Plan for the Town of Perenjori 1. Introduction 1.1 Background The Department of Agriculture and Food, Western Australia (DAFWA) with project partners: CSIRO, CRC LEME, UWA and the WA Chemistry Centre, has delivered the $6 million Rural Towns – Liquid Assets (RT–LA) project. The project was funded by the Western Australian Government, 15 Local Government Authorities and the National Action Plan for Salinity and Water Quality. Other major stakeholders are the Avon Catchment Council, the Northern Agricultural Catchments Council, the South West Catchments Council and South Coast Natural Resource Management Inc. The Project aims to devise solutions to potential and existing townsite salinity problems as well as developing new locally based water resources for rural towns. New research and existing knowledge of groundwater systems will be used to identify water management options and prepare townsite Water Management Plans (WMPs) which focus on improved and integrated water management strategies. The Shire of Perenjori has been involved in the Rural Towns Program since 1998 and is now one of 15 towns participating in the RT-LA project. Perenjori is located approximately 285 kilometres north of Perth in the northern agricultural region of the wheatbelt (Figure 1) and has a population of approximately 200 residents. 1.2 Water management objectives The Perenjori Project objectives are to develop and partially implement a Water Management Plan which will: identify opportunities for ground and surface water resource development, producing water primarily for townsite irrigation alleviate salinity