Historical annual reference potential evaporation is already high in the region and projected increases into the future, highest in spring and summer, will impact on water availability. Higher potential evaporation from dams, wetlands and riparian zones will constitute an unavoidable loss to the region’s water resources. All else remaining the same, soils are anticipated to dry out more rapidly in future, leading to potential negative implications for runoff production. Irrigation water demands will be higher than at present, leading to both increased abstractions from dams and reduction in river flows where irrigation is from run-of-river. The following approaches to adaptation can be considered by growers:
- Seek cooler and more sheltered microsites on farms where ETo is milder;
- Shift to fruit types with a greater physical and economic water productivity;
- Ensure that irrigation practices are optimal, water stress is avoided, and non-productive water use and system losses are minimised;
- Use irrigation technologies and scheduling methods (including remote sensing tools) to maximise water productivity;
- Use mulches and cover crops to reduce soil evaporative water losses, build carbon-rich soil organic matter, and improve the water-holding capacity of the soil;
- Install protective netting to reduce the water demand by the trees;
- Shift fruit cultivation to regions with greater rainfall in summer to reduce the irrigation water requirement;
- Diversify access to diverse sustainable water sources, e.g. utilisation of groundwater in areas where the resource supply is still well in excess of extraction rate and the water is of suitable quality;
- Maximise streamflows, base flows (especially during the dry season and during dry spells and droughts), groundwater recharge, and on-farm potential for water storage during the rainfall season by practicing clearing of invasive alien plants (with regular maintenance), protection / rehabilitation / restoration of wetlands, and using hydrologically appropriate drainage systems in planted areas;
- Help nature to provide water purification services and thus improve water quality by protecting (and not planting in) riparian buffer zones and wetland drainage areas;
- Develop a River Maintenance Management Plan (MMP) in collaboration with LandCare to ensure long-term protection of the water resource and water-related infrastructure;
- Develop a Farm Drought Plan to guide management strategies and actions in times of dry spells and droughts.