SIR Salt and Water Balance Project Protecting Investment in Modernised Irrigation Salinity Risk...
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Transcript of SIR Salt and Water Balance Project Protecting Investment in Modernised Irrigation Salinity Risk...
SIR Salt and Water Balance Project
Protecting Investment in
Modernised Irrigation
Salinity Risk Mitigation in the Shepparton Irrigation RegionTerry Hunter1; John Mansfield1; James Burkitt1; Carl
Walters2
SIR Salt and Water Balance Project
Partnership Acknowledgment
This project is funded as part of the Goulburn Broken Catchment Management Authority Regional Catchment Strategy in the Shepparton
Irrigation Region and is provided with support and funding from the Australian Government and Victorian Government. This project is
delivered primarily through partnerships between the Department of Environment and Primary Industries, Goulburn-Murray Water, the
Goulburn Broken Catchment Management Authority and other bodies.
SIR Salt and Water Balance Project
Where is the SIR?
You are
here
SIR Salt and Water Balance Project
Addressing Salinity Risk in the SIR– The Problem & Solutions in the Past– What’s Changed– New Understandings – Research– Implications for irrigation management and
what is being done to mitigate risk
SIR Salt and Water Balance Project
Late 20th Century
Wet Climate = Extreme & Inevitable Salinity Risk
SIR Salt and Water Balance Project
SIR Land & Water Salinity Management Plan - 1989
Significant investment in Salinity Mitigation. 30 Year Plan to Implement Works & Measures
•On Farm Planning•Surface Drainage•Public Managed Groundwater Pumps•Privately Operated Groundwater Pumps•Monitoring Programs•Community Involvement
SIR Salt and Water Balance Project
SIR Salinity HistorySIR Salinity HistoryEconomic Impacts by mid 1990’s
• 270,000 ha with watertables less than 2 m below NS
• 65,000 ha protected by groundwater pumps
• In current $ terms with no pumping
– Production losses due to salinisation estimated at ~$100 million/year
– Regional losses estimated at ~$400 million/year
SIR Salt and Water Balance Project
A Changed World1. Drought & Flood
SIR Salt and Water Balance Project
SIR Salt and Water Balance Project
SIR Salt and Water Balance Project
SIR Salt and Water Balance Project
SIR Salt and Water Balance Project
SIR Salt and Water Balance Project
SIR Salt and Water Balance Project
A Changed World1. Drought and Flood
2. Modernised Irrigation • Delivery System & On Farm
3. Drivers• Government emphasise on increased food and fibre production
4. Risk & Cost• Understanding
• Perceptions
SIR Salt and Water Balance Project
Understanding Future Salinity Risk
Salt & Water Balance Project (S&WBP)
• Understanding of water balance and salt mobilisation implications under variable climatic and water management regimes
• Development of adaptive management systems and “triggers” for salinity and shallow groundwater resource management
• Harmonisation of salinity management and shallow groundwater resource management
SIR Salt and Water Balance Project
• Hydrology
• Salinity
• Management Framework
Confirmation of ongoing risk of high watertables Recognition that the future risk will vary over time &
space – need adaptive management approach Rates of watertable rise & fall
Confirmation of understanding of salinisation risk Linkage between high watertables & salinisation Use of saline water needs to appropriately managed
Salinity risk management approach for privately pumped shallow groundwater
Salinity risk management system to manage shallow watertables & on-farm use of shallow groundwater within a variable climate
S&WBP Outputs
SIR Salt and Water Balance Project
Adaptive Management Approach
SIR Salt and Water Balance Project
S&WBP Conclusions:
• Winter/Spring rainfall on a wet catchment main driver for watertable response – irrigation wets the catchment
• High watertables (and an associated salinity threat) likely in all situations except severe drought
• Improved irrigation management will help but impact is minor compared with irrigation/rainfall interaction
• The Land & Water Management Plan is sound, however the hydrological loading is significantly more variable than originally envisaged
SIR Salt and Water Balance Project
Implications for Irrigation Management
• The groundwater from private pumps used for irrigation is generally between 500 and 4000 EC
• The use of the groundwater needs to be carefully managed by:
– Shandying (mixing with high quality water)
– Paddock rotation
– Matching irrigation to soil type
– Potentially remediating land (i.e Gypsum application)
• Transitioning from Regulatory Non regulatory approach with landholders managing their own risk
SIR Salt and Water Balance Project
Supporting Irrigators• Agency focus on developing digital delivery channels to
target irrigation landholders
• Targeted information on
– Managing brackish water
– Areas of salinity threat (e.g. risk maps)
– Groundwater level hydrographs
– Options for water table and salinity control
SIR Salt and Water Balance Project
Questions?