Farm Water for the North-Eastern and Eastern Wheatbelt of Western Australia (Zones 2 and 5)
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Research Library Resource management technical reports Natural resources research 2007 Farm water for the north-eastern and eastern wheatbelt of Western Australia (Zones 2 and 5) Susan Murphy-White Follow this and additional works at: https://researchlibrary.agric.wa.gov.au/rmtr Part of the Agriculture Commons, Environmental Indicators and Impact Assessment Commons, Environmental Monitoring Commons, Fresh Water Studies Commons, Hydrology Commons, Natural Resources Management and Policy Commons, Soil Science Commons, and the Water Resource Management Commons Recommended Citation Murphy-White, S. (2007), Farm water for the north-eastern and eastern wheatbelt of Western Australia (Zones 2 and 5). Department of Primary Industries and Regional Development, Western Australia, Perth. Report 318. This report is brought to you for free and open access by the Natural resources research at Research Library. It has been accepted for inclusion in Resource management technical reports by an authorized administrator of Research Library. For more information, please contact [email protected]. FARM WATER FOR THE NORTH-EASTERN AND EASTERN WHEATBELT OF WESTERN AUSTRALIA Susie Murphy-White May 2007 RESOURCE MANAGEMENT TECHNICAL REPORT 318 ISSN 1039-7205 Resource Management Technical Report 318 Farm water for the North-eastern and Eastern Wheatbelt of Western Australia (Zones 2 and 5) Susie Murphy White Dryland Research Institute, Merredin May 2007 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 use or release of this information or any part of it. © State of Western Australia 2007 FARM WATER FOR THE NORTH-EASTERN AND EASTERN WHEATBELT 2 FARM WATER FOR THE NORTH-EASTERN AND EASTERN WHEATBELT Summary Large proportions of Western Australia’s dryland farms suffer from water supply problems in the form of shortages, poor quality or combinations of these two factors. The affected area relates to farmland receiving less than 600 mm average annual rainfall and encompasses most of the State’s commercial dryland farms. Continuing farm water supply problems throughout the north-eastern and eastern wheatbelt have highlighted the need for the development of an integrated approach to on-farm and off-farm water supply. The ‘Water Planning and Management for Sustainable Dryland Agriculture’ project for the North-eastern and Eastern Wheatbelt was funded by the Natural Heritage Trust for three years (July 1996-July 1999). The research was based at the Merredin Dryland Research Institute and focused on developing strategies for Zone 5 and the north-east of Zone 2 that covers the north-eastern and eastern parts of the wheatbelt. The Sustainable Rural Development project and the Sustainability of Wool Production Systems supported the integration of farm water planning into focus catchment planning and the development of agricultural water supply areas to form a Regional Farm Water Plan. Agricultural water supply areas were identified as part of the Regional Farm Water Plan developed for the project. The description of the water supply areas for the north-eastern and eastern wheatbelt will assist landholders in the development of new supplies and guide maintenance strategies and improvement of existing water supplies. A regional study for the North-eastern and Eastern Wheatbelt was undertaken to assist in the development of new and existing water supplies and to define a landform-based approach for surface water management. Five farm water supply areas were identified using natural resource management units that relate to different types of water supply development potential. The base data used to develop water supply areas included soil type, landscape units, geology, hydrogeology, native vegetation and existing farm water resource infrastructure. 3 FARM WATER FOR THE NORTH-EASTERN AND EASTERN WHEATBELT Contents Page 1. Introduction .......................................................................................................... 5 1.1 Historical development of farm water resources .......................................... 7 1.2 Water deficiency ........................................................................................... 9 2. North-eastern and Eastern Wheatbelt biophysical environment .................... 10 2.1 Climate ......................................................................................................... 10 2.2 Geology ........................................................................................................ 12 2.3 Hydrogeology ............................................................................................... 13 2.4 Land systems ............................................................................................... 15 2.5 Vegetation .................................................................................................... 17 2.6 Agricultural systems and water demand ....................................................... 21 3. Agricultural water supply areas ......................................................................... 24 3.1 Tamma: Area 1 ............................................................................................ 26 3.2 Rock: Area 2 ................................................................................................ 28 3.3 Mallee: Area 3 ............................................................................................. 29 3.4 Salmon Gum: Area 4 ................................................................................... 31 3.5 Morrel: Area 5 .............................................................................................. 33 4. Farm water resources development .................................................................. 35 4.1 On-farm water supply planning ..................................................................... 35 5. Water resources research: Needs and opportunities ..................................... 39 5.1 Community issues and attitudes .................................................................. 39 5.2 Low adoption survey .................................................................................... 39 5.3 Focus catchment surveys ............................................................................. 40 5.4 Community water day ................................................................................... 40 6. Conclusion ........................................................................................................... 41 7. References ........................................................................................................... 42 4 FARM WATER FOR THE NORTH-EASTERN AND EASTERN WHEATBELT 1. Introduction The area covered by this report is Zone 5 (North-eastern and Eastern Wheatbelt) and the north-eastern part of Zone 2 (Reticulated Scheme Area) of the Western Australian Farm Water Plan as shown in Figure 1. Although the reliability of water supply in Zone 2 is generally superior to Zone 5, there is ample scope for on-farm water supply development in Zone 2. The Local Government Areas (LGAs) in Zone 5 are Dalwallinu, Koorda, Mt Marshall, Mukinbudin, Westonia, Yilgarn and Narembeen covering 2 million hectares. The LGAs in Zone 2 considered are Trayning, Nungarin, Merredin, Bruce Rock and Kellerberrin. This represents a total of 2.9 million hectares. Figure 1. Western Australian Farm Water Plan Zones (Farm Water Strategy Group 1994) The Yilgarn catchment consists of 5.66 million hectares of land that extend from Kellerberrin to Southern Cross, east and north of Mukinbudin. The catchment is part of the Swan-Avon drainage system and includes the salt lakes which are part of the Zone of Ancient Drainage. These salt lakes exist as a linear chain that are interconnected, but rarely flow as they experience high evaporation and a shallow profile. The Yilgarn catchment was the area that overlapped with Zones 2 and 5 and studied in this project (Figure 2). Four focus catchments were studied from the Yilgarn catchment: Bodallin (Yilgarn LGA), Wallatin Creek (Kellerberrin LGA), Yeelanna and Yarragin TangPlang (Trayning LGA). The study area has a Mediterranean climate with cool wet winters and hot dry summers. Average annual rainfall varies between 280 and 360 mm with approximately two-thirds falling in the growing season (May to September). Average monthly maximum temperature ranges from 16 to 36oC with the average annual evaporation exceeding 2,000 mm. Farming systems are dominated by winter cereal production and grazing of livestock, primarily Merino sheep for wool. 5 FARM WATER FOR THE NORTH-EASTERN AND EASTERN WHEATBELT Mukinbudin Southern Cross Merredin Kellerberrin Zone 2. Reticulated Scheme Area Zone 5. North-eastern and Eastern Wheatbelt Figure 2. Farm Water Plan Zones 2 and 5 overlapped with the Yilgarn catchment Water supplies are described as either low quality (livestock) or high quality (domestic) sources. Low quality water from dams and bores is generally used for livestock, garden, laundry and toilet facilities. High quality water is used for drinking, domestic purposes and for specific needs in farm operations such as crop spraying. The main sources of high quality water are tanks connected to roofed structures and bores. A Farm Water Strategy Group was initiated in 1992 to advise on strategies that would reduce the severity and extent of supply problems. The Farm Water Plan 1994